Steps to Solar Panels
As an Amazon Associate we earn from qualifying purchases.
Get information about solar panels here.
The sun is the original source of all energy,1 and we can all benefit from its resources. But how does solar power actually work? How is it that something as simple as a solar panel can take sunlight and use it to power things like your oven, television, and other appliances like your Xbox?
We can answer that for you. In this article, we’ll define solar for you, explain the solar process and how it works, help you understand where the concept of solar energy originated, explain why the renewability of solar energy can be so impactful, help you understand how solar can save you money, and go over a few other helpful things like how much solar can cost and how it relates to things like batteries and ev chargers. Let’s get started.
What is solar energy?
Solar energy is a type of fuel that’s powered by the sun. That’s really important because (hopefully) the sun will never run dry. We’ll never wake up one day and not see the sun. It’ll always be there (again, fingers crossed). Because the sun shines every day, it is the ultimate source of renewable energy (we’ll talk about that a little later on). We don’t have to refuel the sun unlike gas or oil.
Solar photovoltaics (also know as “PV”) take that sunlight and convert it into electricity, and we capture that electricity with solar panels. In those solar panels exist a ton of atoms (think back to 4th grade science for this). Atoms are the smallest particles of matter that we know of, and at the center of an atom is something called a nucleus (think of it as the heart or brain of the atom). The nucleus is made of tiny things called protons and neutrons. Solar energy works when the photons of an atom knock the electrons free from atoms, generating a flow of electricity.
Solar panels are made up of these small things called PV cells and many PV cells linked together make a solar panel. Most solar cells are made out of silicon. These solar cells are organized into sets or modules and then connected into solar panels, which you see on roofs.
How does solar power work?
Basically, what happens is that your solar panel system uses photons to separate electrons from atoms. Photons are light particles. The process of separating electrons from their atoms creates solar electricity.
Now let's learn more about how solar panels work. When it comes to solar panels, the process can really be summed up in five basic steps:
Step 1. Solar panels capture sunlight
Each solar panel contains photovoltaic (PV) cells. PV cells take light, or photons, and convert it to solar electricity. When sunlight hits the solar panel, PV cells produce direct current (DC) electricity. (Hey… want to know the science behind this in more detail? See the explanation from NASA).
This is all well and good — but DC electricity can't power your home on its own. This is where other pieces of solar power equipment come in. Let's move on to solar inverters!
Step 2. Inverters convert solar energy to useful electricity
Some solar panel system configurations have a single inverter (often called a string inverter) for the entire system. Some have a microinverter connected behind each solar panel. The most important thing to know about inverters is that they convert DC electricity from solar panels to alternating current (AC) electricity. This electricity is what powers your home. Here we go.
Step 3. Solar electricity is used in the home
Solar electricity runs through your net meter, makes itself comfortable in your home, and powers your appliances. It works just like your traditional electricity does now—you don’t have to change a thing. If your solar panels don’t produce enough energy to cover all of your electricity needs, don’t worry. You’re still connected to traditional power companies via the grid, so you can automatically draw more energy from your utility when you need. What happens if you produce more power than you use? Let’s find out.
Step 4. Leftover solar electricity goes to the grid
It might seem counterintuitive to be on the traditional power grid when you have a solar energy system, but being on the power grid has its advantages. It allows you to use as much electricity as you need before sending any excess solar power to your power company to use. Solar panels generate electricity when the sun is up, but we use electricity at night too, when we’re not producing solar power. That’s why it’s important to stay connected to the power grid. Here's how it works:
Step 5. Solar Electricity is measured by the net meter
For this last part, you’ll need to know what a net metering agreement is. Net metering is when your local utility company agrees to provide energy credits for any surplus solar power you produce and send it back to the power grid. In some cases, these energy credits can roll over so you accrue them long-term, and some utilities will even cut you a check for your power production credits.
The net meter device is installed in the home and measures the electricity going to and from the power grid. This meter is similar to the electric meter you probably have now, but it measures power going in two directions instead of just one. Have more questions? Get even more specifics on net metering here.
A note on net metering
It’s important to note that if you have a shared PPA agreement where you pay for the solar energy your panels produce, you will most likely pay more for your solar power in the summer. This seems backward right? Let us explain: summer means more sunlight which also means more solar power production. BUT the good news is because you’re relying less on traditional electricity, it should help offset your total usage costs.
Now add in the value of accruing net metering credits, and while it may seem slow at first, it ends up saving you money in the long-run. Give it about twelve months after you’ve installed your solar energy system to see the net metering process begin to tip in your favor. Where did the idea of solar come from?
From what history we’ve recorded as a people, we know that humanity has been using solar power as far back in history as the 7th century B.C. From focusing solar energy on glass to start fires, to directing sunlight through mirrors to illuminate a room, man has always had a very close relationship with the awesome power of the sun. However, the concept of harnessing solar power via PV cells really came about, from 1839-1883, by the ingenuity of the following five men:
1839: Edmond Becquerel In 1839, French physicist Edmond Becquerel discovered the impact of photovoltaics while experimenting with a cell made of metal electrodes and noted that the cell produced more electricity when it was exposed to light.
1873: Willoughby Smith In 1873, Willoughby Smith discovered that selenium could function as a photoconductor.
1876: William Grylls Adams and Richard Evans Day In 1876 William Grylls Adams and Richard Evans Day applied the photovoltaic principle discovered by Becquerel to selenium and recorded that it could, in fact, generate electricity when exposed to light.
1876: William Grylls Adams and Richard Evans Day In 1883, American inventor Charles Fritz created the first working selenium solar cell.
Why is solar power considered “renewable” and what does that mean?
Remember how we talked about the sun being the ultimate source of renewable energy because it (hopefully) will never run out? When we talk about renewable in terms of solar energy, we’re talking about something that’s sustainable, easy to use, requires very little maintenance, and will keep itself going for a long period of time.
That’s the sun. The sun is renewable because it literally renews itself. It is a source of power that will not run out (again, we hope) which means we can continue using the impacts to generate energy for us without having to refuel of renew it. Aside from the sun, other sources of renewable energy include the wind and hydropower.
The opposite of renewable would be a fossil fuel. Fossil fuels (gas, oil, coal, petroleum, etc.) are not renewable because they require constant refuling, maintenance, and they are finite resources which will eventually run out over time. They are also horrendously bad for the environment because of the amount of carbon emissions they generate which pollutes the air, plants, and this beautiful earth we live on.
Source: Vivint Solar
Obtain resources for solar panels here.
Power play: Utilities want solar users to pay up
Since 2008, the price of solar panels has declined 75 percent.
Solar energy use is exploding in the U.S. In fact, a new rooftop system was installed every four minutes in 2013, according to the Solar Energy Industries Association.
But the growth has utility companies pushing in several states to scale back what they call unfair rate advantages that solar users have long received.
“The principal issue is making sure everyone is paying a fair price for what they use,” said Ted Craver, CEO and chairman of Edison International, the parent company of utility Southern California Edison.
The debate centers on net metering, which requires utility companies to credit customers for solar energy that they generate in excess of their own usage. The credits were part of financial incentives to invest in solar energy.
Policies for net metering, which is used in 43 states, vary from state to state, but most credits are set at the local retail price for electricity. That bothers utilities, which contend that the retail price is set too high, resulting in excessive credits to solar users. Utilities want credits set by wholesale prices, which are much lower than retail.
“We don’t care where or who we buy the power from, but it should be purchased at the wholesale price,” Edison International’s Craver told CNBC.
But some experts say the mere fact that utilities—which generate $360 billion a year in energy sales—are battling with solar indicates the threat it now poses to them.
“The success of solar power is forcing utilities to rethink their business model and push for the changes,” said Franc Del Fosse, an energy industry lawyer and partner at Snell & Wilmer. “If you have an individual putting solar panels on the roof, it’s easy to suggest that a utility is making less money.”
The effort for higher fees on solar panel users could backfire, said Alan Beale, general manager of SolarMax.
If the fees are too high, he said, “it will just delay ... the inevitable, and more companies and individuals will go to the independent energy producers.”
According to Carver at Edison International, part of the problem is that many power users, such as apartment renters, lack access to solar energy, which creates a two-tier system that shifts higher costs to nonsolar users.
According to a policy paper from the Edison Electric Institute, a trade association, solar users avoid paying for the system’s fixed costs but still take power from the grid when they need it, such as after sunset, when solar panels aren’t generating. (Most solar users don’t have solar storage capacity, the paper states.)
The solar industry seems willing to accept some changes but stops at what it sees as the utilities’ exorbitant price proposals.
“Solar customers give much more valuable peak power to utilities for free during the day than they get back at night,” said John Berger, CEO and founder of solar energy provider Sunnova. “Utilities are like socialist monopolies.They don’t provide good service or pricing.”
Solar is now cheap enough to compete
Utility companies are having some success getting net metering rules changed.
In California, the No. 1 solar state in panels installed, lawmakers let net metering continue but directed its public utility commission to devise a new program by 2017 to ensure that nonsolar customers aren’t burdened unfairly in paying for the grid.
In Arizona, regulators voted in November to allow the largest utility to tack a monthly fee of $5 onto the bill of customers with new solar installations. Arizona Public Service originally sought a $50 surcharge.
Colorado’s utility commission is considering a proposal to halve credits for solar energy households. Other states, including Louisiana and Idaho, are also contemplating changes in net metering rates.
Even some solar power users see change as necessary.
“I believe there’s a way of restructuring metering rules and rate structures that won’t impact the solar industry for the long term,” said Karin Corfee, managing director of the energy practice for consulting firm Navigant, who has solar panels on her Danville, Calif., home.
Utility firms have valid cost issues, she said, but she is concerned that fixed rate increases or rate restructuring could affect solar users’ ability to pay off their energy investment.
“I figure I can pay if off in seven years,” Corfee said. “But if decisions are made to shift the economics of my system ... that will be difficult.”
Money is at the heart of solar energy growth.
Since 2008, the price of solar panels has fallen by 75 percent. The cost of installation has also decline as more contractors entered the market. Leasing options for users also fostered growth.
And Wall Street still likes solar. An estimated $13 billion was invested in such projects last year, 10 times as much as in 2007, according to GTM Research,
Even as they push for net metering changes, utilities are jumping on the solar bandwagon.
“We’ve invested in a solar distribution firm ourselves,” said Craver.
“Some utilities have embraced solar and worked with users, while others have not,” said Roy Palk, who spent 37 years in the utility industry and now advises the law firm LeClairRyan on energy. “But solar is not going away and will offer consumers more choices, and that’s good.”
And compromise on net metering may prove elusive, said Del Fosse at Snell & Wilmer.
“The real answer lies somewhere between the two sides, but it’s hard to see if that will happen,” he said. “The marketplace will have to provide solutions.”
—By CNBC’s Mark Koba.
Source: CNBC News
A Solar-Powered Home: Will It Pay Off?
What Is Solar Power for the Home?
Homeowners who install photovoltaic power systems receive numerous benefits: lower electric bills, lower carbon footprints, and potentially higher home values. But these benefits typically come with significant installation and maintenance costs, and the magnitude of the gains can vary widely from one house to another. This article will help homeowners make the financial calculations required to determine the viability of solar power in their homes.
Those seeking to go green may want to consider equipping their home with solar panels.
Not only is solar power good for the environment, but you can earn money selling back excess power to the grid.
While costs have come down over the past years, installation and maintenance of solar panels can be quite costly.
Solar panels are best-suited for homes that receive ample sun exposure throughout the year.
Before committing to solar power, be sure to understand both the social and economic factors.
Understanding Solar Power
Photovoltaic (PV) solar technology has been around since the 1950s, but, thanks to declining solar module prices, it has only been considered a financially viable technology for widespread use since the turn of the millennium.1
Solar panel size is quoted in terms of the theoretical electrical output potential in watts. However, the typical output realized for installed PV systems—known as the "capacity factor"—is between 15% and 30% of the theoretical output.2 A 3 kilowatt-hour (kWh) household system running at a 15% capacity factor would produce 3 kWh x 15% x 24 hr/day x 365 days/year = 3,942 kWh/year, or roughly one-third of the typical electricity consumption of a U.S. household.
But this calculation may be misleading because there is little reason to speak of "typical" results; in fact, solar may make sense for one household, but not for the house next door. This discrepancy can be attributed to the financial and practical considerations considered in determining viability.
Before getting solar panels, get quotes from several reputable installers to compare.
Solar Power for the Home: Costs
Solar power is capital intensive, and the main cost of owning a system comes upfront when buying the equipment. The solar module will almost certainly represent the largest single component of the overall expense.
Other equipment necessary for installation includes an inverter (to turn the direct current produced by the panel into the alternating current used by household appliances), metering equipment (if it is necessary to see how much power is produced), and various housing components along with cables and wiring gear.
Some homeowners also consider battery storage. Historically, batteries have been prohibitively expensive and unnecessary if the utility pays for excess electricity that is fed into the grid (see below). The installation labor cost must also be factored in.
In addition to installation costs, there are some further costs associated with operating and maintaining a PV solar array. Aside from cleaning the panels regularly, inverters and batteries (if installed) generally need replacement after several years of use.
While the above costs are relatively straightforward—often a solar installation company can quote a price for these for a homeowner—determining subsidies available from the government and/or your local utility can prove more of a challenge. Government incentives change often, but historically, the U.S. government has allowed a tax credit of up to 30% of the system's cost.3
More details on incentive programs in the U.S., including programs within each state, can be found on the Database of State Incentives for Renewables & Efficiency (DSIRE) website. In other countries, such information is often available on government or solar advocacy websites. Homeowners should also check with their local utility company to see whether it offers financial incentives for solar installation, and to determine what its policy is for grid interconnection and for selling excess power into the grid.
The U.S. installed 19.2 gigawatts of solar PV capacity in 2020 to reach 97.7 GWdc of total installed capacity, enough to power 17.7 million American homes.
4. Solar Power for the Home: Benefits
A significant benefit to PV installation is a lower energy bill, but the magnitude of this benefit depends on the amount of solar energy that can be produced given the available conditions and the way in which utilities charge for electricity.
The first consideration is the solar irradiation levels available in the home's geographical location. When it comes to using solar panels, being closer to the equator is generally better, but other factors must be considered. The National Renewable Energy Laboratory (NREL) produces maps for the U.S. showing solar irradiation levels; the tools on its website provide detailed solar information for specific locations within the U.S.5
Similar maps and data are available in other countries as well, often from government environmental agencies or renewable energy organizations. Equally important is the home's orientation; for rooftop arrays, a south-facing roof without trees or other objects obstructing sunlight maximizes the available solar energy. If this is not available, panels can be mounted on external supports and installed away from the house, incurring additional costs for the extra hardware and cables.
The second consideration is the timing of solar power production, and how utilities charge for electricity. Solar power generation occurs primarily during the afternoon and is higher during summer, thus corresponding relatively well to overall electricity demand in warm climates because it is at these times that air conditioners consume the most energy. Consequently, solar power is valuable because the alternative methods of energy production (often natural gas power plants) used to meet peak energy demand tend to be expensive.
But utilities often charge residential consumers a flat rate for electricity, regardless of the time of consumption. This means that instead of offsetting the expensive cost of peak electricity production, homeowners' solar power systems merely offset the price they are charged for electricity, which is much closer to the average cost of power production.
However, many utility companies in the U.S. have introduced pricing schemes that allow homeowners to be charged at different rates throughout the day in an attempt to mirror the actual cost of electricity production at different times; this means higher rates in the afternoon and lower rates at night. A PV solar array may be very beneficial in areas where this sort of time-varying rate is used since the solar power produced would offset the most costly electricity.
Exactly how beneficial this is for a given homeowner depends on the exact timing and magnitude of the rate changes under such a plan. Similarly, utilities in some locations have pricing schemes that vary over different times of the year due to regular seasonal demand fluctuations. Those with higher rates during the summer make solar power more valuable.
Some utilities have tiered pricing plans in which the marginal price of electricity changes as consumption rises. Under this type of plan, the benefit from a solar system can depend on the electricity use of the home; in certain areas subject to rates that increase dramatically as consumption increases, large homes (with large energy needs) may benefit most from solar arrays that offset high-cost marginal consumption.
Another benefit of a solar system is that homeowners can sell solar-generated electricity to utilities. In the U.S., this is done through "net metering" plans, in which residential consumers use the power that they put into the grid (when the rate of electricity generation from the solar array is greater than the rate of household electricity consumption) to offset the power consumed at other times; the monthly electric bill reflects net energy consumption. The specific net metering regulations and policies vary across regions. Homeowners can refer to the DSIRE database and should also contact their local utilities to find more specific information.
The final benefit is the potential effect on a home's value due to the addition of a solar array. In general, it is reasonable to assume that solar panels would raise the value of most homes.
First, there is an undeniable financial benefit to having lower electricity bills as a result of a solar array. Second, the trend toward "green" living means there is a growing demand for homes that have a smaller carbon footprint and are powered by renewable sources.
Finally, buying a home with solar already installed means the investment is financed (for the homebuyer) through the mortgage. This ease of financing potentially makes solar more affordable for a homebuyer than buying a house without solar and subsequently adding a solar array.
Calculating Solar Power Costs
Once the above costs and benefits are determined, a solar system can theoretically be evaluated using the discounted cash flow (DCF) method. Outflows at the beginning of the project would consist of installation costs (net of subsidies), and inflows would arrive later in the form of offset electricity costs (both directly and through net metering).
Rather than using DCF, the viability of solar power is usually evaluated by calculating the levelized cost of electricity (LCOE), then comparing it to the cost of electricity charged by the local utility. The LCOE for household solar will typically be calculated as cost/kilowatt-hour ($/kWh or ¢/kWh) - the same format commonly used on electricity bills. To approximate the LCOE, one can use the following equation:
LCOE ($/kWh) = Net Present Value (NPV) of the Lifetime Cost of Ownership ($) / Lifetime Energy Output (kWh)
The useful life of a PV solar module is generally assumed to be 25-40 years.6 The cost of ownership includes the maintenance costs, which must be discounted to find the NPV. The LCOE can then be compared to the cost of electricity from a utility; remember, the relevant price is that which occurs during times at or near peak PV solar production.
Pros and Cons of Solar Panels for Your Home
Like most things, solar power has its benefits and drawbacks. At the same time, some economic costs may be defrayed by the social benefits to the environment and lowering your carbon footprint, which exceeds pure monetary evaluation.
Green energy that lowers your carbon footprint
Net metering allows you to sell back excess energy produced
You may be eligible for certain tax breaks
Installation and maintenance costs still high
Solar only works when the sun is out
Parts of the system need to be replaced every few years
Some tax breaks may have expired or will be expiring
Frequently Asked Questions
Can a House Run on Solar Power Alone?
Practically, it is not often possible. This is because solar only works when the sun is shining - which means when it is cloudy or nighttime, they do not generate electricity. There are some battery solutions to provide power during these times, but they still tend to be quite expensive. Most homes with solar panels still rely on the grid from time to time.
Do You Really Save Money With Solar Panels?
Depending on where you live, it is possible that the system can pay itself back and more over time. This is because you won't be spending as much money buying electricity from your utility, and if net metering is in place you can reduce your bills even further,
How Much Does a Solar Panel Cost?
Prices have been coming down steadily over the years. The total cost will depend on how many kilowatts of power your array will generate. According to consumer reports, after solar tax credits are accounted for, the cost for a solar panel system on an average-sized house in the U.S. in 2021 ranges from $11,000 to $15,000.7.
How Long Will It Take for Solar Panels To Pay for Themselves?
Depending on where you live and the size of your system, it can take on average anywhere from 10 to 20 years to breakeven on a solar installation.
The Bottom Line
Determining whether to install a PV solar system may seem like a daunting task, but it is important to remember that such a system is a long-term investment. In many locations, solar power is a good choice from a financial perspective.
Even if the cost of solar power is found to be marginally more expensive than electricity purchased from a utility, homeowners may wish to install solar power to avoid future potential fluctuations in energy costs, or may simply wish to look beyond their personal financial motivations and use solar for "green" living.
We make nothing from these financing resources and can neither endorse nor not endorse these resources. We Simply offer them as a resources and invite you to contact us with your feedback for the benefit of the SR Garden & Cook Community. Thank you.
3. Training & Education
Learn about solar panels here.
Grid & Hybrid Systems
On-Grid, Off-Grid and Hybrid Systems
All solar power systems work on the same basic principles. Solar panels first convert solar energy or sunlight into DC power using what is known as the photovoltaic (PV) effect. The DC power can then be stored in a battery or converted by a solar inverter into AC power which can be used to run home appliances. Depending on the type of system, excess solar energy can either be fed into the electricity grid for credits, or stored in a variety of different battery storage systems.
The three main types of solar power systems
1. On-grid - also known as a grid-tie or grid-feed solar system
2. Off-grid - also known as a stand-alone power system (SAPS)
3. Hybrid - grid-connected solar system with battery storage
Simplified layout of a common grid connected (on-grid) solar power system
First we will describe the common components used by all three types before going into more detail about the different systems and how they work.
Main Components Of A Solar System
Winaico 300W mono PERC solar panel
Most modern solar panels are made up of many silicon based photovoltaic cells (PV cells) which generate direct current (DC) electricity from sunlight. The PV cells are linked together within the solar panel and connected to adjacent panels using cables. Note: It is sunlight or irradiance, not heat, which produces electricity in photovoltaic cells. Solar panels, also known as solar modules, are generally connected together in ‘strings’ to create a what is known as a solar array. The amount of solar energy generated depends on several factors including the orientation and tilt angle of the solar panels, efficiency of the solar panel, plus any losses due to shading, dirt and even ambient temperature. There are many different solar panel manufacturers on the market, so it worth knowing which are the best solar panels and why.
Solar panels can generate energy during cloudy and overcast weather, but the amount of energy depends on the 'thickness' and height of the clouds, which determines how much light can pass through. The amount of light energy is known as solar irradiation and usually averaged over the whole day using the term Peak Sun Hours (PSH). The PSH or average daily sunlight hours depends mainly on the location and time of year.
Fronius Primo solar ‘string’ inverter
Solar panels generate DC electricity which must be converted to alternating current (AC) electricity for use in our homes and businesses. This is primary the role of the solar inverter. In a ‘string’ inverter system, the solar panels are linked together in series, and the DC electricity is brought to the inverter which converts the DC power to AC power. In a micro inverter system, each panel has its own micro-inverter attached to the rear side of the panel. The panel still produces DC, but is converted to AC on the roof and is fed straight to the electrical switchboard.
There are also more advanced string inverter systems which use small power optimisers attached to back of each solar panel. Power optimisers are able to monitor and control each panel individually and ensure every panel is operating at maximum efficiency under all conditions.
Batteries used for solar energy storage are available in two main types, lead-acid (AGM & Gel) and lithium-Ion. There are several other types available such as redox flow batteries and sodium-ion but we will focus on the most common two. Most modern energy storage systems use rechargeable lithium-ion batteries and are available in many shapes and sizes which can be configured in several ways.
Battery capacity is generally measured is either Amp hours (Ah) for lead-acid, or kilowatt hours (kWh) for lithium-ion. However, not all of the capacity is available for use. Lithium-ion based batteries can typically supply up to 90% of their available capacity per day, while lead-acid batteries generally only supply 30% to 40% of their total capacity per day to increase battery life. Lead-acid batteries can be discharged fully, but this should only be done in emergency backup situations.
Off-grid solar systems require specialised off-grid inverters and battery systems large enough to store energy for 2 or more days. Hybrid grid-connected systems use lower cost hybrid (battery) inverters, and only require a battery large enough to supply energy for 5 to 10 hours (overnight) depending on the application.
In a common grid-tie solar system, AC electricity from the solar inverter is sent to the switchboard where it is drawn into the various circuits and appliances in your home. This is known as Net metering, where any excess electricity generated by the solar system is sent the electricity grid through an energy meter or stored a battery storage system if you have a hybrid system. Some countries however, use ‘Gross metering’ where all solar energy is exported to the electricity grid.
Hybrid systems can both export excess electricity and store excess energy in a battery. Some Hybrid inverters maybe also be connected to a dedicated backup switchboard which enables some ‘essential circuits’ or critical loads to be powered during a grid outage or blackout.
1. On-Grid System
On-grid or grid-tie solar systems are by far the most common and widely used by homes and businesses. These systems do not need batteries and use either solar inverters or micro-inverters and are connected to the public electricity grid. Any excess solar power that you generate is exported to the electricity grid and you usually get paid a feed-in-tariff (FiT) or credits for the energy you export.
Unlike hybrid systems, on-grid solar systems are not able to function or generate electricity during a blackout due to safety reasons. Since blackouts usually occur when the electricity grid is damaged; If the solar inverter was still feeding electricity into a damaged grid it would risk the safety of the people repairing the fault/s in the network. Most hybrid solar systems with battery storage are able to automatically isolate from the grid (known as islanding) and continue to supply some power during a blackout.
In an on-grid system, this is what happens after electricity reaches the switchboard:
The meter. Excess solar energy runs through the meter, which calculates how much power you are either exporting or importing (purchasing).
Metering systems work differently in many states and countries around the world. In this description I am assuming that the meter is only measuring the electricity being exported to the grid, as is the case in most of Australia. In some states, meters measure all solar electricity produced by your system, and therefore your electricity will run through your meter before reaching the switchboard and not after it. In some areas (currently in California), the meter measures both production and export, and the consumer is charged (or credited) for net electricity used over a month or year period. I will explain more about metering in a later blog.
The electricity grid. Electricity that is sent to the grid from your solar system can then be used by other consumers on the grid (your neighbours). When your solar system is not operating, or you are using more electricity than your system is producing, you will start importing or consuming electricity from the grid.
2. Off-Grid System
An off-grid system is not connected to the electricity grid and therefore requires battery storage. Off-grid solar systems must be designed appropriately so that they will generate enough power throughout the year and have enough battery capacity to meet the home’s requirements, even in the depths of winter when there is generally much less sunlight.
The high cost of batteries and off-grid inverters means off-grid systems are much more expensive than on-grid systems and so are usually only needed in more remote areas that are far from the electricity grid. However battery costs are reducing rapidly, so there is now a growing market for off-grid solar battery systems even in cities and towns.
AC-coupled off-grid solar systems use a solar inverter together with a multi-mode battery inverter.
There are different types of off-grid systems which we will go into more detail later, but for now I will keep it simple. This description is for an AC coupled system, in a DC coupled system power is first sent to the battery bank, then sent to your appliances. To understand more about building and setting up an efficient off-grid home see our sister site go off-grid/hybrid
Simple, affordable, small scale DC-coupled off-grid solar power system use solar charge controllers to manage the battery charging, plus an a simple inverter to supply AC power.
The battery bank. In an off-grid system there is no public electricity grid. Once solar power is used by the appliances in your property, any excess power will be sent to your battery bank. Once the battery is full it will stop receiving power from the solar system. When your solar system is not working (night time or cloudy days), your appliances will draw power from the batteries.
Backup Generator. For times of the year when the batteries are low on charge and the weather is very cloudy you will generally need a backup power source, such as a backup generator or gen-set. The size of the gen-set (measured in kVA) should to be adequate to supply your house and charge the batteries at the same time.
3. Hybrid System
Modern hybrid systems combine solar and battery storage in one and are now available in many different forms and configurations. Due to the decreasing cost of battery storage, systems that are already connected to the electricity grid can start taking advantage of battery storage as well. This means being able to store solar energy that is generated during the day and using it at night. When the stored energy is depleted, the grid is there as a back up, allowing consumers to have the best of both worlds. Hybrid systems are also able to charge the batteries using cheap off-peak electricity (usually after midnight to 6am).
There are also different ways to design hybrid systems but we will keep it simple for now. To learn more about the different hybrid and off-grid power systems refer to our detailed guide to home solar battery systems.
The battery bank. In a hybrid system once the solar power is used by the appliances in your property, any excess power will be sent to the battery bank. Once the battery bank is fully charged, it will stop receiving power from the solar system. The energy from the battery can then be discharged and used to power your home, usually during the peak evening period when the cost of electricity is typically at it’s highest.
The meter and electricity grid. Depending on how your hybrid system is set up and whether your utility allows it, once your batteries are fully charged excess solar power not required by your appliances can be exported to the grid via your meter. When your solar system is not in use, and if you have drained the usable power in your batteries your appliances will then start drawing power from the grid.
Source: Clean Energy Reviews
Types of solar panels
Most of the solar panel options currently available fit in one of three types: monocrystalline, polycrystalline (also known as multi-crystalline), and thin-film. These solar panels vary in how they’re made, appearance, performance, costs, and the installations each are best suited for.
Depending on the type of installation you’re considering, one option may be more suitable than the others.
The major types of solar panels
There are three major types of solar panels: monocrystalline, polycrystalline, and thin-film. Each type has its own unique advantages and disadvantages, and the solar panel type best suited for your installation will depend on factors specific to your own property and desired system characteristics.
Solar panel type
Portable and flexible
Below, we’ll break down some common questions and concerns about solar panels and how different types of panels have varying characteristics.
What are different solar panels made of?
To produce electricity, solar cells are made from a semiconducting material that converts light into electricity. The most common material used as a semiconductor during the solar cell manufacturing process is silicon.
Monocrystalline and polycrystalline solar panels.
Both monocrystalline and polycrystalline solar panels have cells made of silicon wafers. To build a monocrystalline or polycrystalline panel, wafers are assembled into rows and columns to form a rectangle, covered with a glass sheet, and framed together.
While both of these types of solar panels have cells made from silicon, monocrystalline and polycrystalline panels vary in the composition of the silicon itself. Monocrystalline solar cells are cut from a single, pure crystal of silicon. Alternatively, polycrystalline solar cells are composed of fragments of silicon crystals that are melted together in a mold before being cut into wafers.
Thin-film solar panels
Unlike monocrystalline and polycrystalline solar panels, thin-film panels are made from a variety of materials. The most prevalent type of thin-film solar panel is made from cadmium telluride (CdTe). To make this type of thin-film panel, manufacturers place a layer of CdTe between transparent conducting layers that help capture sunlight. This type of thin-film technology also has a glass layer on the top for protection.
Thin-film solar panels can also be made from amorphous silicon (a-Si), which is similar to the composition of monocrystalline and polycrystalline panels. Though these thin-film panels use silicon in their composition, they are not made up of solid silicon wafers. Rather, they’re composed of non-crystalline silicon placed on top of glass, plastic, or metal.
Lastly, Copper Indium Gallium Selenide (CIGS) panels are another popular type of thin-film technology. CIGS panels have all four elements placed between two conductive layers (i.e. glass, plastic, aluminum, or steel), and electrodes are placed on the front and the back of the material to capture electrical currents.
What do different solar panel types look like?
The differences in materials and production cause differences in appearance between each type of solar panel:
Monocrystalline solar panels
If you see a solar panel with black cells, it’s most likely a monocrystalline panel. These cells appear black because of how light interacts with the pure silicon crystal.
While the solar cells themselves are black, monocrystalline solar panels have a variety of colors for their back sheets and frames. The back sheet of the solar panel will most often be black, silver or white, while the metal frames are typically black or silver.
Polycrystalline solar panels
Unlike monocrystalline solar cells, polycrystalline solar cells tend to have a bluish hue to them due to the light reflecting off the silicon fragments in the cell in a different way than it reflects off a pure monocrystalline silicon wafer.
Similarly to monocrystalline, polycrystalline panels have different colors for back sheets and frames. Most often, the frames of polycrystalline panels are silver, and the back sheets are either silver or white.
Thin-film solar panels
The biggest differentiating aesthetic factor when it comes to thin-film solar panels is how thin and low-profile the technology is. As their name suggests, thin-film panels are often slimmer than other panel ty[es. This is because the cells within the panels are roughly 350 times thinner than the crystalline wafers used in monocrystalline and polycrystalline solar panels.
It’s important to keep in mind that while the thin-film cells themselves may be much thinner than traditional solar cells, an entire thin-film panel may be similar in thickness to a monocrystalline or polycrystalline solar panel if it includes a thick frame. There are adhesive thin-film solar panels that lie as-close-as-possible to the surface of a roof, but there are more durable thin-film panels that have frames up to 50 millimeters thick.
As far as color goes, thin-film solar panels can come in both blue and black hues, depending on what they’re made from.
What are bifacial solar panels?
Bifacial solar panels can capture sunlight from both the front and back of the panel, thus producing more electricity than comparably sized, traditional solar panels. Many bifacial solar panels will have a transparent back sheet so that sunlight can go through the panel, reflect off the ground surface and back upwards towards the solar cells on the back side of the panel. These solar panels are typically manufactured with monocrystalline solar cells, but polycrystalline bifacial solar panels exist as well.
Solar panel power and efficiency ratings
Each type of solar panel varies in the amount of power it can produce.
Monocrystalline and polycrystalline solar panels.
Of all panel types, monocrystalline typically have the highest efficiencies and power capacity. Monocrystalline solar panels can reach efficiencies higher than 20 percent, while polycrystalline solar panels usually have efficiencies between 15 to 17 percent.
Monocrystalline solar panels tend to generate more power than other types of panels not only because of their efficiency but because they have come in higher wattage modules as well. Most monocrystalline solar panels come with more than 300 watts (W) of power capacity, some now even exceeding 400 W. Polycrystalline solar panels, on the other hand, tend to have lower wattages.
This doesn’t mean that monocrystalline and polycrystalline solar panels aren’t physically the same size - in fact, both types of solar panels tend to come with 60 silicon cells each, with 72 or 96 cell variants (usually for large-scale installations). But even with the same number of cells, monocrystalline panels are capable of producing more electricity.
Thin-film solar panels
Thin-film solar panels tend to have lower efficiencies and power capacities than monocrystalline or polycrystalline varieties. Efficiencies will vary based on the specific material used in the cells, but they usually have efficiencies closer to 11 percent.
Unlike monocrystalline and polycrystalline solar panels that come in standardized 60, 72 and 96 cell variants, thin-film technology does not come in uniform sizes. As such, the power capacity from one thin-film panel to another to another will largely depend on its physical size. Generally speaking, the power capacity per square foot of monocrystalline or polycrystalline solar panel will exceed thin-film panel technology.
Do any solar panels have more than 96 cells?
Though not as common as 60, 72, or 96 cell panels, some solar panel manufacturers produce solar panels with half-cut cells, essentially doubling the number of solar cells within the panel. Half-cut solar cells are monocrystalline or polycrystalline solar cells cut in half using a laser cutter. By cutting the solar cells in half, solar panels can experience marginal gains in efficiency and durability.
Different types of solar panels have varying costs.
The manufacturing processes differ between monocrystalline, polycrystalline, and thin-film; as such, each type of panel comes with a different price tag.
Monocrystalline solar panels
Of all types of solar panels, monocrystalline panels are likely to be the most expensive option. This is largely due to the manufacturing process - because the solar cells are made from a single silicon crystal, manufacturers have to absorb the costs of creating these crystals. This process, known as the Czochralski process, is energy intensive and results in wasted silicon (that can later be used to manufacture polycrystalline solar cells).
Polycrystalline solar panels
Polycrystalline solar panels are typically cheaper than monocrystalline solar panels. This is because the cells are produced from silicon fragments rather than a single, pure silicon crystal. This allows for a much simpler cell manufacturing process, thus costing less for manufacturers and eventually end users.
Thin-film solar panels
What you pay for thin-film solar panels will largely depend on the type of thin-film panel; CdTe is generally the cheapest type of solar panel to manufacture, while CIGS solar panels are much more expensive to produce than both CdTe or amorphous silicon.
Regardless of the cost of the panel themselves, the overall cost of a thin-film solar panel installation may be lower than installing a monocrystalline or polycrystalline solar panel system due to additional labor requirements. Thin-film solar panel installations are less labor-intensive because they are lighter weight and more maneuverable, making it easier for installers to carry panels up onto rooftops and secure them in place. This means reduced labor costs, which can help contribute to an overall less expensive solar installation.
Type of panel best for your installation
As you’re choosing the type of solar panel you’d like for your system, much of your decision will come down to the specifics of your property and situation. Monocrystalline, polycrystalline, and thin-film panels each have their own advantages and disadvantages, and the solution you should move forward with depends on your property and your goals for the solar project.
Property owners with a lot of space for solar panels can save money upfront by installing lower efficiency, lower-cost polycrystalline panels. If you have limited space available and are looking to maximize your electric bill savings, you can do so by installing high-efficiency, monocrystalline solar panels.
As far as thin-film panels go, it’s most common to choose this type of solar panel if you’re installing on a large, commercial roof that cannot handle the additional weight of traditional solar equipment. These types of roofs can also afford the lower efficiencies of thin-film panels because they have more area to place them on. Additionally, thin-film panels can sometimes be a useful solution for portable solar systems, like on RVs or boats.
Source: Energy Sage
The Positive and Negative Environmental Impacts of Solar Panels
Are solar panels as green as you think? There are good and bad environmental impacts of solar power...
Are solar panels really that ‘green’? The environmental impacts of solar panels are widely discussed and commented on but what arguments are valid, and what is social media noise?
Key arguments against solar panels are that they require more energy and fossil fuel-burning equipment to mine, manufacture, and transport than they save. Another argument is that toxic chemicals are used in the manufacturing process which do more harm than good.
Solar power isn’t perfect
On the other side, it is argued that solar panels create more clean energy than they take to create and top global companies are truly leading by example with regards to chemical usage.
Here we will examine the positive and negative environmental impacts of solar panels and what the future has in store for the solar energy industry.
Negative Environmental Impacts Solar Panels
Let’s start by stating the obvious - solar power isn’t perfect. Like everything in life, there are upsides and downsides.
This is especially true for small topics like generating energy for 7 billion people in a sustainable, economical way.
Solar power is not without its downsides. Let’s examine them here:
1. Energy Demand - Solar requires a significant amount of energy up front to produce. Mining, manufacturing and transportation all require substantial amounts energy. Quartz must be processed, and cleaned and then manufactured with other components which may come from different facilities (aluminum, copper etc..) to produce a single solar module. Heating the quartz during the processing stage requires very high heat. Manufacturing requires combining multiple materials with incredible precision to produce high efficiency panels.
All of this requires lots of up-front energy. With traditional fuels such as gas or goal,they are extracted, cleaned/processed and burned at very large scales,typically in a single location.
2. Chemicals – To produce solar-grade silicon, semi-conductor processing typically involves hazardous chemicals. Depending on the solar panel manufacturer and country of origin, these chemicals may or may not be disposed properly. Like every industry, there are companies leading by example, and others which cut corners to save cash. Not every company will dump chemicals, or won’t recycle their byproducts properly, but there are bad apples out there.
3. Recycling – What happens when solar panels break or are decommissioned? Although solar panel recycling has not become a major issue yet, it will in the coming decades as solar panels need to be replaced. Currently, solar modules can be disposed of with other standard e-waste. Countries without robust e-waste disposal means are at a higher risk of recycling related issues.
These are the major environmental concerns surrounding the PV industry. The fear is certainly cause for further investigation but may be unfounded according to the numbers.
Chemicals, Recycling and Disposal of Solar Panels
Recycling and disposal of solar panels is a key area of concern. There is a clear problem with solutions on the horizon.
This is not as widespread or toxic as it may seem though. Standard solar modules' silicon wafers are encapsulated, commonly by ethyly vinyl acetate (EVA). This layer protects the silicon wafer. If modules are not disposed of properly and exposed to specific test conditions is it possible some leaching may occur. Under normal operating conditions these materials will not be released.
Solar power is very effective at carbon mitigation. As with all technologies, the unintended waste or byproducts is something that must be dealt with.
An obvious answer is to recycle solar panels and sell their base elements. Great in theory, but this path is not an economical, scalable one – yet.
Large scale solar panel recycling plants do exist, but are not as prevalent as they need to be.
This lag is expected with new industries and technologies. Auto recyclers did not appear the day after the Model T rolled off the line. Bottle depots were not waiting around for the advent of bottles. E-waste recyclers have just recently become common place, decades after the explosion of consumer electronics.
It takes time for secondary industries to develop around primary industries.
An alternative or additional solution to aid the economics of recycling is to put a fee onto solar panel manufacturers to ease the recycling process or mandate a recycling program be implemented from the manufacturers.
Both options will take time to implement and perfect.
The economics of solar panel recycling will be improved as more solar panels are decommissioned. Higher volumes in any industry allow the economics of scale to work their magic.
A simple solution to the chemicals used in solar panels would be to find alternative methods for manufacturing modules. This solution is already underway, although its timeline for commercialization is difficult to predict.
Although chemicals are used in solar panels production, comparison to traditional fuels may provide useful context. Generating any form of energy on a mass scale will require some use of chemicals in the supply chain.
Coal must be chemically cleaned and treated after mining. Fracked natural gas must be extracted using chemical mixtures. Both coal and gas are combusted to create electricity. Nuclear energy itself requires the handling of extremely radioactive materials.
No fuel source is perfect, each has their own environmental advantages and disadvantages. But some are better than others.
Environmental Impact of Solar Panel Manufacturing
How are solar panels made and what are the environmental impacts of that process?
Solar panels have few components: a frame, cells, backsheet, protective film, conductors and a tempered glass cover. The frame is aluminum, the cells are silicon, the conductors are copper and the backsheet & film are typically a polymer or plastic-based material.
Components of a Solar Panel
To make solar panels, the raw material must be mined, this is predominantly Quartz which is processed into silicon. Aluminum, and copper or silver are also key materials involved which must be mined, or obtained from recycled sources, but mostly they are mined due to the increased expansion of the PV industry in the last 10 years.
Following the mining of raw materials, the quartz is processed into electronic-grade silicon. This process involves heating the quartz in a high temperature furnace and reacting it with various chemicals.
Other manufacturing processes are required for forming the extruded aluminum frame and rolling the tempered glass. Manufacturing anything generally requires vast amounts of energy.
Solar Panel Manufacturing Process
Solar panels take a lot of energy to create, but the total emissions are heavily front-loaded. After solar panels are installed, they produce emission-free energy for 25+ years.
The manufacturing process is irrelevant without context of the lifetime generated energy as well as how other fuel sources stack up.
The answers to two key questions will provide this context:
1. Does the clean energy generated from solar panels offset the negative impacts during the mining and manufacturing process?
2. How does solar power’s emission intensity compare to traditional electricity fuel sources such as coal?
Carbon Emission Intensity of Solar Panels and Other Fuels
Emission intensity is the lifetime (total) carbon emissions evaluated per unit of energy. This is shown by grams of carbon dioxide equivalent per kilowatt-hour (gC02e/kWh) or an equivalent value, tons of carbon dioxide equivalent per megawatt-hour (tC02/MWh).
The lower the emission intensity, the better the environmental impact, as less CO2 is emitted to generate the same amount of energy.
Lifetime Carbon Emissions from Solar
To paint a clear picture of solar's carbon footprint, hundreds of life cycle assessments studies have been performed over the past couple decades on solar power’s emission profile.
These assessments included upstream, operational and downstream stages of energy generation from various fuel sources such as the solar PV, solar thermal, wind, nuclear, natural gas and coal.
In 2014, the U.S. Department of Energy’s National Renewable Energy Laboratory (NREL) screened 400 of these studies accounting for discrepancies, outliers and other variable contributing factors to the data. The data was then harmonized using a discrete set of assumptions for comparison purposes.
The results showed that solar panels require approximately 60% to 70% of their energy upfront, approximately 25% during operation and approximately 5% to 20% following their productive life.
Coal on the other hand generated ~98% of its emissions during the operation process (mining, transportation, combustion etc) and only 1% during upstream and downstream processes.
Solar panels today are nearly 50% more efficient than when this study occurred.
As one might expect fossil fuel-based energy generation methods produce more CO2 than renewable sources per kWh.
What one might not have expected is just how large of a gap there is between the fuel types.
Emission Intensity of Electricity Fuels by Type, NREL 2014.
The life cycle emission intensity of solar PV is approximately 40 gC02/kWh.
The life cycle emission intensity of coal is approximately 1,000 gC02/kWh.
Coal produces 25x more carbon dioxide than solar energy to produce the same amount of energy.
Emission Intensity Variance
One caveat to note in favour of renewable energy is that the silicon solar panels in NREL’s harmonization were 13.2% to 14.0% efficient.
This was the accurate in the years leading up to 2014, but today, poly-crystalline solar modules regularly achieve efficiencies of >19.5%.
Solar panels today are nearly 50% more efficient than when this study occurred. Creating more kWh’s of clean energy from the same manufacturing deficit which will further reduce solar PV’s emission intensity.
Even the worst estimates for solar PV is still 3x better than the best estimates for coal (both situations being true is unlikely).
The median and harmonized values paint a more accurate picture of the emission intensity of the fuel types (accounting for statistical outliers).
The harmonized value also considered a solar irradiance value of 1700kWh/m2 which is approximately equal to the levels seen across Alberta and Saskatchewan.
Emission intensity is an incredibly important metric that must be considered when evaluating the environmental impacts of solar power.
Other studies and meta-analysis have been conducted which confirm the environmental impacts of solar panels compared to other fuel sources found by NREL.
Energy Payback Time of Solar Panels
If solar panels take more energy to create than they will produce over their lifetime, or similarly, if the upstream effects of solar panel manufacturing are worse than the operational benefits, the technology is fundamentally flawed.
People often look at the return on investment (ROI) or payback period to gauge the value of a financial investment. How long will it be until I get my money back?
A 25-year payback period doesn’t get most people excited but a 3-year payback period would have most investors’ attention.
This same question can be framed for energy generation and assessing the environmental impact of solar panels – how long will it be until the solar power system generates enough energy to offset the energy it took to produce?
The energy payback period for solar power depends on your location as different weather patterns affect solar generation. A solar panel installed in the Sahara Desert will produce more energy and payback much quicker than the same panel installed above the arctic circle.
Once again, NREL provides some noteworthy data. This data includes manufacturing of the module, frame and balance of system components.
Solar Panels Energy Payback Time, NREL 2004
Multi-crystalline solar panels have an energy payback period of just 2 years.
Another favourable caveat to note is that value is based off an assumed solar panel efficiency of 14%. Today, solar panels are 40% to 50% more efficient.
With that in mind, it is reasonable to assume that solar panels have an approximate energy payback period of 1 to 2 years.
If you were offered an investment with a 2-year payback period, would you take it?
Electricity Fuel Sources Environmental Impact
The environmental benefits of solar also vary depending on what form of energy is displaced.
As the earlier figure suggests, generating solar energy instead of using coal-fired grid electricity will be far more advantageous than if you were installing solar panels to offset primarily hydro or wind electricity from the grid.
There are a number of other reasons to install solar panels even if your grid is powered by renewable sources (such as relieving pressure on the grid and lowering your lifetime cost of electricity ownership) but those won’t be detailed here.
Canada's energy generation by province and fuel type. Compiled by Kuby Renewable Energy.
Provinces such as Nova Scotia, Saskatchewan and Alberta would benefit from solar power the most since energy in these provinces come from primarily fossil fuels.
Quebec stands to gain the least from solar power deployment as their grid is already nearly emission-free.
Solar power is not perfect, but overall it provides a positive net environmental impact and financial impact.
Yes, vast amounts of energy are required to mine/manufacture solar panels and yes, chemicals are used during the manufacturing process. These two irrefutable facts do not equate to solar panels having a net negative impact though, as the data suggests.
The energy required to create a solar panel will be recouped in less than 2 years. Even considering the manufacturing and processing stage of solar, the emissions generated are 3x to 25x less than generating the same amount of energy from fossil fuels.
The reduced emissions from using solarenergy versus any fossil fuel (especially coal) make the technology extremely beneficial.
Source: Kuby Energy
Solar Panels - Buyer's Guide
A Dynamic Industry
At times, supply delays and surpluses have plagued the solar industry. For example, China slashed solar subsidies for domestic solar installations in May 2018. This move created a lag in demand, causing a surplus of solar panels and falling prices across the industry. More recently, the Trump administration enacted a U.S. solar tariff on panels, but this is tapering down. Also, the federal tax credit was extended by two years at 26%, effective in 2021.
Because solar panel technology is advancing, the market is very dynamic. New products are frequently being released as others become obsolete. The cost of advanced solar batteries has been dropping as demand has surged. The most efficient solar panels on the market today will probably not seem so efficient in a decade as the technology matures. Companies that are relatively unknown could capture a larger share of the market.
Solar Panel Considerations
Solar panels have become significantly more efficient in recent years. And the more efficient a solar panel is, the more electricity it generates in a given space. Space becomes more critical when there are constraints due to the size of your roof or property. Unfortunately, more efficient panels typically cost more. If space isn’t an issue, efficiency becomes less crucial. For installations limited by space, panel efficiency is an essential consideration. It is also important to consider the long-term efficiency of solar modules.
Long-Term Power Generation
Like most other things, solar panels degrade over time. They become less efficient in turning sunlight into electricity. Degradation is important because solar panels can last 30 years or more. You want your solar system to be churning out a lot of energy a couple of decades from now, even if someone else owns the house.
Solar panel manufacturers offer a power production guarantee to ensure a particular output level over a given time. Many solar panel manufacturers guarantee 90% production for 10 years and 80% for 25 years.
Some manufacturers differentiate themselves by offering more robust warranties. For example, SunPower leads the industry by providing a 25-year performance guarantee of 92% or higher, depending on the model. The higher the value of the 25-year production warranty, the more power the panels will likely generate 25 years down the road.
Product warranties cover defects and failures, helping to protect your investment. Solar panel warranties vary a lot by the manufacturer, and this often corresponds with the price range of the solar panel. For example, SunPower and Silfab offer a 25-year product warranty, whereas Trina and Jinko offer just a 10-year warranty. The longer the warranty, the lower the investment risk. In many cases, a more extended product warranty means higher solar panel prices.
Also, just because the manufacturer offers a long product warranty doesn’t mean the solar installer will provide a warranty that’s just as long. Thus, it might be necessary to pay an installer to replace defective panels even if the manufacturer’s warranty covers the equipment.
The Silicon Valley Toxics Coalition (SVTC) is dedicated to a safe and sustainable solar photovoltaic (PV) industry. They produce a solar scorecard that rates manufacturers on extended producer responsibility, supply chain, workers rights, emissions reporting, module toxicity, greenhouse gas emissions, conflict minerals, and water use. The companies with the highest ratings are the most sustainable.
Solar Panel Module Testing
Look for DNV GL test results. The company tests solar panels for reliability and durability for common degradation mechanisms. Solar panel performance has a significant impact on the solar electricity of an array over time. Such testing helps ensure high-quality panels, reducing financial risk.
Source: Earth 911
Learn how to implement solar panels here.
15 Things to Consider Before Installing Rooftop Solar Panels
Across the United States, more and more people are starting to invest in solar power systems. They are outfitting their roofs with solar panels — and why not? Solar power technology has seen incredible advancements in recent years, many of which have helped to lower the cost of the equipment involved. Installing solar panels on your roof is also a wonderful way to generate electricity for your home and business, as well as the grid, without increasing your impact on the environment.
However, there are many things that you need to consider before you jump in and start the installation process. Understanding the different factors involved in a project like this is so important — taking a look at common solar panel myths is a good idea, too.
To help you decide whether or not solar power is the right option for you, your home, or your business, we’ve put together a list of the top 15 things you need to take into consideration before you install those rooftop solar panels.
1. Does your roof need repairs?
Before you even consider installing solar panels, ask yourself, how old is my roof? If you know that you will need a new roof soon, or that a part of your roof is damaged, it probably isn’t the best idea to install solar panels. If you can, take care of any roof repairs before the installation. That way, you won’t need to pay extra to dismantle the work and then put it up again (in some cases for at least 20 years).
Another aspect to consider is the warranty on your roof compared to the warranty on the solar panels. If you have solar panels that will last for 20 years and a roof that will only last between 10 – 15, it increases the cost of maintenance. Try to match both projects in terms of how long they will last in order to reduce the amount of effort, time and money you will need to invest.
2. What is the shape of your roof?
Roofs come in many different shapes and sizes. Before you go ahead with any installation, make sure that your roof has enough space for the solar panels. If there isn’t enough room, you likely will not get the return you expect on your investment.
3. Which direction do the slopes of your roof face?
Solar panels require specific placement in order to generate the maximum amount of power. Most professionals say that the best placement is to have the panels face south while others say west. Regardless, this information is important for you to determine before the installation starts.
4. How much weight can your roof handle?
Installing solar panels will increase the weight on the structure of your roof. If the weight of these solar panels is too much for your roof to handle, there is a potential that it will collapse. This is very dangerous for many reasons, not to mention costly. To avoid both situations, it is critical to have a professional evaluate your roof to determine if additional support is required to complete the installation.
5. Where will the water go?
When it rains, water runs down the roof, into the gutters and out and away from your home. When installing solar panels, equipment like racking and wire harnesses can prevent the water from flowing and draining properly. In some cases, solar equipment can move the water in a different direction, which can create leaks and other problems. These problems will need repair, which means the solar panels will need to be removed.
To avoid all of these issues, make sure that you inform your contractor of these concerns. They will be able to present a plan to you to prove that the installation will not impact the water runoff in any way.
6. What about nature’s other surprises?
Part of maintaining your solar power system is dealing with severe weather like lightning storms, hurricanes, hail, and more. There is a potential for some solar power equipment to get damaged during these events. While some insurance will cover these types of events, it is something to consider, especially if you live in an area where this type of weather occurs often.
7. How do you connect to the grid?
In addition to the structure and shape of your roof, you also need to consider how you are going to connect your solar power system to the grid. When connecting with a local utility, there are many things that you need to determine.
How long will it take to get hooked up?
Do you need to pay any fees?
How will you be credited for the generated electricity?
When will you be credited for your generated electricity?
8. Did you shop around?
Before signing any agreement with a contractor, make sure that you’ve done your research. Picking the first contractor you come across might seem like a quick and easy way to start saving money sooner rather than later. However, this isn’t necessarily true! If you are serious about installing solar panels on your roof, shop around and get different quotes from different contractors. Do some research on these companies to make sure that they are reputable and their customers are satisfied.
After you speak with a few contractors, you will be glad you did. You can compare quotes, customer reviews, and other information to make the best, informed decision.
Signing a Contract
When you are ready to sign a contract, there are a few things to look out for in the agreement. Some of these items include:
Entities that might collect data on your electricity production and usage
Companies that have access to your electricity production and usage data
If this information is not clearly defined in the contract, you might want to ask the contractor a few clarification questions. Never sign for anything you are not comfortable with!
9. Do you trust your contractor?
Installing a solar power system is both a home improvement and electrical project. This is why when you start your search for the right contractor, you validate that they have the correct credentials. For example, asking if they have accreditation from the North American Board of Certified Energy Practitioners (NABCEP) is a good place to start.
Choosing a contractor that you feel will also be around for the long term is also an important factor to consider. While there is little maintenance that is required, if something stops working, you want your contractor available to fix it under warranty.
10. Did you pick the cheapest options?
Cheaper solar panels rarely translate to better solar panels. While the technology has dropped significantly in price over the past decade, investing in the cheapest models or brands of solar panels can leave you in the dark. Cheaper or low end solar panels are often manufactured in a way that makes them less durable. When solar panels are less durable, it decreases your investment value as well as potential future savings. The scary part is that these lower quality panels can sometimes be dangerous, resulting in safety hazards. The last thing you want is to have a fire start in your home because of low quality solar panels.
As a consumer, it is so important to invest the time and money into installing the right solar panels. In the long run, it they will last longer and give you a much higher return.
11. What about warranties?
Warranties are an important aspect of protecting your solar panels and other related equipment. If anything happens to your solar panels, having a warranty helps you to keep the manufacturer accountable — without any additional cost to you. There are also some incentive programs (available in many different states) that require you to have a warranty for your solar equipment.
If you don’t have a warranty, these programs will not accept your application.
Types of Warranties
A few different types of warranties exist for solar panels, equipment and installation. Some of these warranties include,
Solar Panel Warranty
This type of warranty should cover your solar panels for 25 – 30 years. If the warranty offered to you is for less than 25 years, understand that this is considered lower than the industry standard. This warranty covers a guaranteed minimum power output over the warranty period of the panel. Industry standards indicate that you should receive a minimum of 80% energy output for the length of time the panels are covered under the warranty.
This warranty covers situations where the solar panels and related equipment have been installed incorrectly. These types of warranties can generally last from 2 – 10 years. Many of these warranties cover things like, the labor and parts related to repair or replacing elements of the system, roof penetrations, shipping, replacing defective parts, and more. For more information, make sure to ask your contractor what kind of installation warranties they provide.
This type of warranty can change from company to company.
That being said, there are a few industry standards that can help you to get a better idea about the warranties that you should be offered. Standard “string inverters”, which handle power from a “string” of panels, often have a warranty period between 5 – 10 years. Generic “micro-inverters”, which attach to individual panels, have warranties that can last between 20 – 25 years. Inverter warranties generally cover, material or manufacturing defects and flaws. Inverter warranties generally don’t cover, improper installations, normal wear and tear caused by extreme conditions, and improper maintenance.
12. Do you have the right insurance?
Having the right insurance to cover both yourself and any damage to your home during installation is something you absolutely need to consider. Many problems can arise during the installation of your solar panels that you might not even think about until it happens. In addition, before the work can even begin many building codes, requirements for rebates, legal regulations and certifications require insurance. These rules and regulations vary by state, so it is important to contact the correct resources for your state before your project starts.
13. Did you take advantage of rebates?
The cost of installing a solar panel system in your home can cost anywhere between $10,000 and $30,000. The good news is many states, cities and solar companies in the United States offer rebates for installing solar panels on your roof. Before your project begins, ask your contractor what options they have and if they don’t have any options, they should know of rebates that are offered by the state and city.
Overall, the government really wants to get people interested in investing in solar power. The Department of Energy itself offers as much as 30% in savings through rebates and tax credits. Your local utility and electricity providers might also offer savings.
14. Can you really DIY?
Solar panel installation is best left to the professionals. Period. There are many things that could potentially go wrong if you aren’t properly trained in the installation process. Examples include:
Wiring Problems: This is a job that requires you to work with electrical elements. If setup incorrectly, you can generate electricity shocks that are harmful to you and everyone around you. Always consult an electrician for any electric work.
Leaky Roof: Installing solar panels require you to create holes in the roof. If these holes are not created or sealed properly, you will damage your roof and cause leaks.
Safety Standards and Code Compliance: Many solar panel warranties require installation by a licensed professional. If you install that equipment yourself, those warranties become void. If there is any damage caused during installation, or if there is problem with the way the panels were manufactured, you will not receive any compensation.
In addition, building permits and other related rules and regulations are difficult to follow if you are not familiar with them. All paperwork must be completed correctly because the project can be rejected.
15. Don’t forget about maintenance.
Keeping your solar panels working and your roof in good condition is all about establishing proper maintenance procedures. It’s a good idea to find out from your contractor what those maintenance procedures are before the installation begins. If you are unable to meet those maintenance requirements, there is a good chance your equipment will not last as long as you want it to.
Source: Electric Choice
How Much Does Solar Panel Installation Cost?
AVERAGE COST:$9,255 - $28,000
Solar panel installation costs a national average of $18,500 for a 6kW solar panel system for a 1,500 square ft. home. The price per watt for solar panels can range from $2.50 to $3.50, and largely depends on the home’s geographical area. Residential solar panels are usually sized at 3kW to 8kW and can cost anywhere from $9,255 and $28,000 in total installation costs. See average solar panel system costs by size (before tax credits or discounts).
How Much Do Solar Panels Cost?
These are a few main factors that will determine exactly how much it will cost to install solar panels on your home:
Your home’s average utility costs and energy usage
Your rooftop’s solar potential, or the amount of sun it receives yearly
The average local cost for a solar panel system in your area
The average labor costs and demand in your area
Local incentives and rebates you could receive
Keep in mind that the cost to install solar panels varies from state to state. However, according to the Department of Energy, the cost to install solar panels is dropping nationally year over year due to new solar energy initiatives.
Solar costs dropped dramatically in the last few years, when the Chinese government influenced the worldwide solar market by pouring low-cost financing into the sector, which boosted solar panel manufacturing more than ten-fold. The DOE’s goal is to cut solar installation costs by half by 2030, which means now is the time to invest.
Solar Panel Installation Costs by Size
Solar Panel SizeAverage Solar Installation Costs
What Size Solar Panel System Do You Need?
The average home uses 905 kWh per month, or around 10,850 kWh per year, in electricity. The average size home with a decent amount of sunshine could install a 5 kW to 6 kW solar panel system to help reduce utility bills. You may want to learn about your sun number score for solar based on your home’s location and average sunlight exposure discussed below. Also explore the different solar panels dimensions and sizes for more context.
The larger the solar panel system you install for your home, the lower the cost per watt will be. The cost per watt – including solar panels, parts, labor costs, permits, and overhead – is between $6 a watt and $8 a watt.
With solar panels, the money you save on your electricity bills can more than earn back your initial installation costs in 7 to 20 years. There are plenty of solar rebates and incentives available from both the government and local energy providers, which can significantly speed up your return on investment.
You may also be able to participate in selling excess electricity from your solar panels by net metering in your area.
Additional Solar Panel System Costs
There are a few things you’ll want to add to your solar energy system’s total cost to get the most accurate price estimate. Here are a few additional factors that will impact how much your solar panels will cost:
Labor costs – Local labor costs for solar installation will change depending on your area and the average costs solar installers charge in your area.
Installing solar mounts – The costs to install the racks that hold your residential solar panels will effect cost as well. There are a few options for solar mounting.
Installing solar inverters – A solar inverter will need to be installed to transform direct current (DC) power from the panels into the alternating current (AC) you can use in your home
Other costs: There may also be costs for any local permit fees, inspection fees, and taxes on the solar panels.
With the fall in solar panel prices, these “soft solar panel costs” now constitute the bulk of what you pay when you install solar for your home.
Fortunately, as more people adopt solar power, soft costs have fallen as a result—a trend that’s very likely to continue in the future. An analysis by the federal government’s National Renewable Energy Laboratory (NREL) discovered that installed prices have fallen at an average annual rate of 13% to 18%.
Always make sure to speak with a local solar professional to get a more accurate estimate of what your installation will cost.
How Many Solar Panels Will You Need?
To know how many solar panels you will need, you will want to determine how much electricity you use in your home and the solar panel types installed.
The average house in the United States uses about 900 kilowatt hours (kWh) a month—roughly 11,000 kWh a year. You can easily calculate your actual usage by looking back at your electricity bills. As a general rule of thumb…
A 3-kWh solar panel system will generate about 3,600 kWh – 4,800 kWh per year.
A 5-kWh system produces about 6,000 – 8,000 kWh per year.
A 10-kWh system can produce about 12,000 kWh – 16,000 kWh per year.
Depending on the size of the system, the solar panels’ cost would be between $4,000 and $16,000. Add in another $3,000 to $10,000 for other necessary components, such as racks for the panels, wiring, solar inverter costs, and the total solar panel installation cost would now be closer to $20,000.
TALK TO CONTRACTORS
How Does Sunlight Amount Affect Solar Panels?
Different areas of the United States receive more or less sunlight compared to other areas. The amount of sunlight you receive directly correlates with how many solar panels you will need.
Typically, southern states get more sun than northern states. But southern states with higher altitudes and less cloud cover—think of Arizona and New Mexico—get more energy from the sun than states such as Florida or Georgia. So, for the same size house, you would generally need more solar panels in Georgia than you would in Arizona.
Remember, the sun may be shining, but if it is behind a cloud, you’re not getting the same amount of solar energy absorbed by your solar PV system. This means that a solar panel in San Diego will produce more energy in a year than the same exact solar panel located in Seattle.
The image below will help you determine the solar energy, known as solar insolation, in your area. Exploring your sun number score should also be helpful. If your roof does not get a good amount of sunlight and you live on a good size amount of land, you may have other options for mounting solar panels elsewhere with better sunlight.
What is the ROI on Solar Panels?
You can calculate the return on investment for installing solar panels by calculating your total payback. Calculate the amount you spent to install a solar panel system and then figure out the amount you will save on energy bills monthly. These two numbers show how quickly your savings will cover your initial costs. Electricity rates will vary by region, being higher in the Northeast than in the Northwest. Solar tends to be more cost effective where electricity prices are high and sunshine is abundant.
In a March 2021 Modernize survey, 40 percent of homeowners said they are actively pursuing home improvement projects to save money on their utility and electric bills. Installing solar panels is an energy-efficient way to save money on energy bills for the long-term. Learn more by exploring Modernize’s Homeowner
Does Solar Net Metering effect ROI?
In states where net metering is in effect, consumers can sell the excess solar energy they produce back to their local utility. That lowers their electricity bill, shortening their payback period and raising their cost savings.
Should You Lease Solar Panels?
There are several payment options that bundle solar installation costs into a consumer’s electric bill, either as a solar panel leasing option or as a power purchase agreement (PPA). Solar leases allow the homeowner to install solar panels without paying anything (or much) up front reducing the overall solar panel cost. After the panels are installed, the homeowner pays only a flat monthly fee. The fee includes the installation costs, which are spread out over time, and the cost of electricity supply.
These type of third-party financing arrangements have a lot of benefits for consumers—the best being no large out-of-pocket investment. And the solar system becomes cash flow positive from day one. Not surprisingly, these agreements have been a big factor in driving today’s solar energy installation boom.
It is worth noting that under most solar lease arrangements, the solar company usually keeps any incentives that are associated with owning the solar panels. But the consumer