Everything you Need to Know About Modern Residential Solar Panel Roofs
Solar power is a renewable energy source that can offer a wide range of benefits for homeowners. Until fairly recently homeowners had to choose between an appealing roof that was attractive but that did not offer the ability to capture solar energy or a roof that provided solar power using large solar panels that stood out and detracted from the home architecture and aesthetics though.
That is no longer the case with the development of residential solar panel roofing though. Today it can be difficult to tell which homes utilize solar panel because new panel models are designed to flawlessly blend with the rest of the roof instead of standing out and detracting from the appearance of the home.
How do Solar Panel Roofs Work?
Solar panels have photovoltaic cells embedded in them. These PV cells have the ability to convert sunlight into electricity, or more specifically into direct current or DC power. An inverter is then used to convert the DC power collected into alternating current or AC electricity that can be used to power the electrical components of your home. An electrical panel controls the power that has been collected, sending electricity to appliances, lights, and other electrical components when power is needed.
Batteries can be used to store any excess electricity that is not needed at the time of collection. This energy can be used at a later time or even sold back to a local utility company for credits on future energy bills so that the energy can be used on the grid for other customers. A utility meter will measure energy that is drawn by the solar panels and fed back to the grid to keep track of what you are using and supplying.
Traditional Solar Panels Versus Solar Panel Roofing Materials
Traditional solar panels can be effective but they have many drawbacks. The panels can be large and bulky, they are installed over the roof so they are highly visible, the panels may not stand up well to adverse or extreme weather conditions, and they can detract from the overall look and beauty of the home.
Solar panel roofing materials eliminate many of the drawbacks that traditional solar panels have. Solar shingles with photovoltaic cells have been developed which get rid of the panels that sit on top of the roof. These specialized shingles are strategically placed on the surface of the roof to provide protection and collect solar energy when sunlight is available. Areas where PV shingles can not be placed are covered with shingles that do not contain the special PV cells, providing a roof that is attractive and that seamlessly blends both shingle types while still capturing any solar energy available.
Home Design and Solar Panel Roof Integration
Modern residential solar panel roofs combine architecture and home design with innovative solar panel technology, providing products that look great, that blend well into the roof and complement neighboring residences, and that are highly effective. Since the PV cells are embedded in the shingles there is nothing to stick up, leaving the roof flat and attractive. Solar roofing panels will collect sunlight without making the residence stand out from the rest of the neighborhood or lowering the property value of the home. You no longer have to choose between going green and using renewable solar energy or a home that is attractive and comfortable.
Solar panel roofs can be installed on any type of architecture. These roofs are becoming increasingly popular, and they can be found on residences, commercial buildings, industrial structures, and even on government buildings in some areas. Home design and architecture plans for new residences will typically consider alternative renewable energy sources as well as conventional energy sources from the very beginning of the planning stage. Many architects and home designers are integrating solar panel roofs into residential design from the start today because of the energy efficiency they provide and the beauty that they offer to any home.
New Homes Versus Existing Residences
Solar panel roofs can be installed on both new homes and existing homes, but the costs and requirements may be different depending on a number of variables. Some variables include:
A new residence does not have an existing roof that may need to be removed, and the roof deck and other roofing structures can be planned for almost any weight load or design element.
Wiring in new homes can be designed to support any necessary components for solar energy conversion and other energy factors.
Older homes may require upgrades before solar panel roofing can be installed.
Installing a solar panel roof on an existing home can significantly cut energy costs as long as the home is well insulated and other energy conservation and weatherization efforts have been made as well.
Solar panel roofing can be easily implemented in the planning stage for a new residence. Adding this element to an existing home can be more challenging but it is still possible and usually very affordable as well.
Costs Associated with Installing Solar Panel Roofs
Solar panel roofs have come down considerably in price since the first PV panels were introduced. Today solar energy can be both affordable and effective, providing beauty and energy efficiency to your home at the same time. Tesla offers a solar panel roof that looks identical to the roof on neighboring residences by using specially designed glass tiles. Some of these glass tiles are embedded with advanced technology PV cells and some that do not have these specialized cells. The result is a roof that is consistent in appearance.
The cost of installing a solar panel roof can vary widely, depending on many factors and considerations. Some considerations include:
The cost of the solar energy technology used. A Tesla solar panel roof and a traditional roof with added solar panels may have comparable costs when the entire roof is replaced or a roof is installed on a new residence.
Is full roof replacement necessary? If a new roof is needed then replacing the existing roof with a solar panel roof should not be much more expensive. If only minor roof repairs are necessary or the roof is still in great condition then replacing the entire structure with a solar panel roof may not be cost effective at this time.
How much energy storage do you want? Some type of energy storage technology will be used to capture any excess solar energy that the PV cells collect. It is important that you have enough energy storage capacity so that no solar energy is wasted. Batteries are typically used to store any extra energy that is not being currently used. The Tesla solar panel roof offers the Powerwall, which can efficiently store extra energy until it is needed or sent to the grid.
Roof size matters. The square footage of the roof will be a factor in calculating the costs involved in installing solar panel roofing. A larger roof will require more components and roofing materials than a smaller roof, meaning more material expenses and a higher labor cost as well.
Where can Solar Panel Roofs be Used?
Solar panel roofs can be installed almost anywhere, but they are most cost effective and efficient in areas that receive a fair amount of sun much of the year. A location that receives more sun means more solar energy will be collected, and less energy will be needed from other sources. Even homes in colder climates can benefit from solar panel roofs, because at least some of the roof will be exposed to sunshine much of the time even when the temperatures drop.
Solar panel roofs are in demand across the USA, from California to Washington to Colorado. Cities and states which see sunshine all year long started the solar energy trend but the rest of the country has caught on to the benefits of solar energy as well.
Industry Leaders in the Solar Roof Panel Industry
In the solar panel industry there are some industry leaders who really stand out, and one of the most prominent is Tesla. The solar panels, solar panel roofing options, and Powerwall energy storage options available make the move to renewable solar energy an easy one. The Tesla solar panel roof offers flawless beauty, a streamlined look and design, and a high level of energy efficiency and conservation. Gone are the ugly solar panels of the past, the unsightly devices that perch on the roof and detract from the beauty of the home.
Adding solar power to your home without drawing away from the architecture and beauty of the structure is easy and affordable today when compared to the past. The Tesla solar panel roof does not stand out in a negative way, instead it blends seamlessly so that the residence has all of the appeal that you want plus an increase in energy efficiency. Any architectural style or home design plan can benefit from a solar panel roof, as long as the right solar products are chosen from an industry leader.
Tesla Solar Roof in Florida?
We were lucky enough to have recently met with the Tesla team regarding solar roofing in Florida. Their current estimation is an availability date in 2019, unfortunately, our customers will have to wait until then. However, when you see the first Tesla solar panel roof, whether Orlando, Miami, Tampa, Jacksonville, Fort Lauderdale, it will be a Phil Kean home!
New solar roof emulates asphalt shingles, right down to the nails
- Tim De Chant
- 01/4/2022 7:17 pm
- Categories: Tech
reader Комментарии и мнения владельцев
A new solar technology introduced yesterday at CES could bring power-producing roofs mainstream by relying on an old building material—nails.
For years, homeowners who wanted solar power have stripped their old roofs of shingles, added new ones, and then slapped large solar panels on top using sturdy frames. It’s a model that works well, but it also creates a two-step process that engineers have been striving to simplify.
Plenty of companies have offered their own take on solar roofs, but so far, they’ve remained niche products. GAF Energy is hoping to change that with the Timberline Solar Energy Shingle that looks strikingly like typical asphalt shingles. But their key feature isn’t so much that they emulate the look of asphalt shingles, but that they’re installed in nearly the same way. Roofers can slap the flexible sheets down and nail the top strip to the roof, just like they do for traditional roofs.
By relying on the shingle installation process, GAF Energy is counting on the scale of the roofing industry to make solar more accessible. “The roofing ecosystem is 20–30 times larger than solar. In the United States, 200,000–300,000 people get a new solar system each year. Over 5 million get a new roof,” Martin DeBono, CEO of GAF Energy, told Ars. “Our innovation is you now have a nailable solar roof, which fits the way that the majority of roofs are installed.”
New spin on an old idea
The solar roof concept has been around for years, and so far the best known is Tesla’s. Their solar roofs are stylish and subtle, with power-producing shingles that are nearly indistinguishable from regular tiles. But despite several revisions, they remain challenging to install at a reasonable cost. Just this year, the company significantly increased the cost of its solar roofs, adding a “roof complexity” factor that affects the total price.
GAF Energy’s approach attempts to simplify several parts of the process. The first, DeBono said, is customer acquisition. Solar installers spend enormous sums to sign up new customers, which gets added on to the price of each installation. Last year, installers spent 0.75 per watt to find new customers, according to analysts at WoodMackenzie. On a typical 7 kW system, customer acquisition adds 5,250, or about 23 percent of the system’s cost. By comparison, DeBono said that “roofers spend very little on sales and marketing.”
The company sought to reduce the time and complexity of the installation process by using a format that roofers are familiar with. They also increased the dimensions of each shingle, which reduces the total install time for the entire roof.
Lastly, GAF Energy moved much of the wiring on top of the roof rather than burying it beneath the shingles. Rows of solar shingles are daisy-chained together and connected with wiring runs that look like seams on a metal roof. Each wiring run supports 2 kW of solar panels. Roofers make the electrical connections between shingles, and an electrician inspects them all when installing the inverter and tying the system into the grid.
Plenty of tweaks
Engineers changed the wiring layout based on the company’s experience with previous generations of solar roof. “With our current product, Decotech, the wires are underneath,” DeBono said. “It’s a bear when the inspector wants to see the wiring—you’re taking off flashing. And similarly for other built-in photovoltaic roofs if the inspector says, ‘I want to see all the connections are made,’ you’re going to be popping up the waterproof layer to show them.” With the new top-mounted system, installers just have to pop off a waterproof cover. It’s an approach that should also make troubleshooting and repairs simpler.
DeBono also said that the panel’s smaller scale made it easier to wring more efficiency out of the system. “Because each one of our panels is 45 Watts and only 10 volts, we have access to a whole host of electronic components that don’t have to be able to withstand 300 Watts, 50 volts,” he said. “That allows us to be more efficient in the electricity generated from those panels.”
The panels themselves are made out of monocrystalline PERC cells, which stands for “passivated emitter and rear contact,” a type of construction that allows some of the photons that pass through the panel to be reflected back to it. That helps boost efficiency to 23 percent per cell, DeBono said. (He wouldn’t say who their supplier is but made a point to say that they’re not made in China.) The cells are fixed to a flexible substrate and topped with a hardened glass that’ll withstand hail. The entire system can withstand hurricane-force winds up to 130 mph, and it’s Class A fire rated. UL certified the shingles as both solar panels and roofing materials, a first, and they can be walked on like traditional shingles.
Though the entire system uses one inverter, GAF Energy added electronics to the panels to allow them to cope with shading. And because the solar shingle panels are relatively small, they should be able to deliver more power under shady conditions than traditional, larger panels.
The entire roof comes warrantied for 25 years, and DeBono said they will be offering a more comprehensive warranty that will also include guaranteed power output. Plus, he points out that GAF Energy’s parent company, Standard Industries, has been around for over a century. “Whether we succeed or fail, the parent company is going to be around to honor our warranty claims,” he said.
Is the price right?
The big question, of course, is price. DeBono wouldn’t give a hard number since the total cost includes installation and the rest of the roof, all of which vary by market. But “a homeowner won’t pay any more for a GAF solar roof than they would if they were to get a new roof and have someone put solar on it. That’s our benchmark,” he said. “We’re half the cost of a Tesla solar roof in any given market right now.”
Though GAF Energy announced the shingles yesterday, DeBono said they’ve already been installing them in various markets in the US. “We’ve actually installed this. We’ve got permits, we’ve passed inspections.”
DeBono is hoping that, by selling a new roof and solar power as one package, his company can convince more people to go solar. “What we say,” he said, “is that with this roof, mister and misses customer, you can generate enough electricity that it will not only pay for the solar system, but also pay for the roof itself. And that’s a very compelling value proposition.”
Solar Roof Shingles 2023 Cost and Buying Guide
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Kristina Zagame is a journalist, editor and content writer with expertise in solar and other energy-related topics. Before joining EcoWatch, Kristina was a TV news reporter and producer, covering a wide variety of topics including West Coast wildfires and hurricane relief efforts. Kristina’s reporting has taken her all over the U.S., as well as to Puerto Rico and Chile. Learn About This Person
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Karsten is an editor and energy specialist focused on environmental, social and cultural development. His work has been shared by sources including NPR, the World Economic Forum, Marketwatch and the SEIA, and he is certified in ESG with the CFA Institute. Before joining EcoWatch, Karsten worked in the solar energy sector, studying energy policy, climate tech and environmental education. A lover of music and the outdoors, Karsten might be found rock climbing, canoeing or writing songs when away from the workplace. Learn About This Person
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- Solar Shingles Cost is High Up Front But ROI is Higher
- Cost of Installing a Solar Shingle Roof
- How to Calculate the Cost of Your New Solar Roof Shingles
- Factors That Go Into Solar Roof Shingle Pricing
- Pros and Cons of Installing Solar Roof Shingles
- Lifetime and Durability of Solar Roof Shingles
- Are Solar Shingles Environmentally Friendly?
- Financing Your New Solar Roof Shingles
- Costs of Maintenance and Repairs for Solar Roof Shingles
- Costs of Cleaning Your Solar Shingles
- Are Solar Roof Shingles Worth the Cost?
- FAQs: Solar Shingles vs Solar Panels
Find the best price from solar installers in your area.
Solar Shingles Cost is High Up Front But ROI is Higher
The average cost of solar roof shingles ranges between 25,000 to 60,000. or between 15 to 35 per square foot. for the average U.S. roof size of 1,700 square feet. The total cost will depend on the solar roof tile brand and the roofing contractor you choose for installation.
Compared to traditional solar panels, solar shingles are much more aesthetically pleasing. They look like mini solar panels shaped in the form of traditional roof shingles, allowing homeowners to bypass the bulky appearance of standard photovoltaic (PV) panels.
If you are interested in adding solar panels to your new roof. solar shingles are a much more cost-effective option. With solar shingles, you’ll knock out the cost of a roof replacement and the cost of a renewable energy system with one combined price tag.
SunPower designs and installs industry-leading residential solar and storage solutions across all 50 states. With a storied history of innovation dating back to 1985, no other company on this list can match SunPower’s experience and expertise.
SunPower earns its position as the top national installer on our list for a handful of reasons: It installs the most efficient solar technology on the residential market, offers the most expansive service area and backs its installations with a warranty well above the industry standard. All the while, SunPower pioneers sustainability efforts within the industry.
If that weren’t enough, SunPower systems come packaged with products all manufactured in-house by its sister company, Maxeon. This means that your panels, solar cells, inverters, battery and EV chargers are designed to work together and are all covered under the same warranty.
SunPower’s biggest downside? Its high-efficiency panels are considerably more expensive than most of its competitors’ products. However, its powerful panels are workhorses that make up for the initial cost with more backend production (think about this like spending more money for a car that gets more miles per gallon).
Facts and Figures: SunPower
|Solar Panels, Solar Batteries, EV Chargers, System Monitoring|
|25-year all-inclusive warranty|
Blue Raven Solar
We like Blue Raven Solar because it understands that, for most homeowners, the cost of solar presents the biggest barrier to entry.
For that reason, Blue Raven Solar developed an innovative solar financing plan that offers in-house, flexible, zero-money-down options. The results speak for themselves, as Blue Raven Solar is now one of the fastest-growing solar companies in the nation and was recently acquired by SunPower. Its BluePower Plus plan (exclusive to Blue Raven) mimics the flexible structure of a lease while still providing the greatest benefits of owning your system.
Eligible homeowners enjoy 18 months of solar power before having to pay their first bill. When coupled with the federal solar investment tax credit (ITC), the initial energy savings can offset more than a third of the overall cost of a system before requiring a dollar down.
In contrast, other installers can only offer similar financing through solar leases, PPAs or third-party providers (such as Mosaic or Sunlight). Third-party loan providers can complicate the process, while opting for a loan or PPA will disqualify you from some of solar’s biggest benefits (additional property value, federal solar tax credit and local solar incentives).
Facts and Figures: Blue Raven Solar
|Solar Panels, System Monitoring|
|Trina Solar, Canadian Solar, SolarEdge, Silfab, SunPower|
|25-year manufacturer warranty; 10-year workmanship warranty, 2-year production guarantee|
ADT Solar sets the industry standard for warranty coverage by including a multifaceted guarantee, making it one of the top installers for homeowners who want added peace of mind.
Its warranty coverage includes all of the following for 25 years:
- Power Production Guarantee: Also known as a performance guarantee, this ensures your solar system will produce the amount of electricity that’s outlined in your proposal, or ADT will write you a check for the difference.
- Labor Guarantee: This covers any issues with the installation of your system and is also known as a workmanship warranty.
- Panel Module Performance Guarantee: This is what ADT Solar refers to the manufacturer warranty as, and it ensures that any manufacturing defects are repaired or your ineffective panels replaced.
- Enphase Microinverters Guarantee: This backs the performance of your inverters.
Though in recent years other solar companies have started to offer similar guarantees, ADT Solar has been at it since 2008, performing over 30,000 installations across the country.
Facts and Figures: ADT Solar
|Solar Panels, Solar Batteries, EV Chargers, Energy-Efficiency Upgrades|
|Silfab, Panasonic and others depending on location|
|25-year all-inclusive warranty|
Cost of Installing a Solar Shingle Roof
The overall cost for a solar shingle installation ranges between 25,000 to 60,000 for the average U.S. home, which comes out to around 15 to 35 per square foot.
But unlike regular shingles, shingles with solar cells — a type of building-integrated photovoltaic (BIPV) technology — are priced per watt. not per square foot. The cost of a solar shingle ranges between 3.50 and 8.00 per watt depending on the brand.
Most solar companies don’t advertise pricing online, but market research shows the total cost of a solar shingle installation is typically 15%-25% higher compared to a traditional solar panel system installation. The national average solar panel installation costs roughly 24,000, which puts the national average solar shingle installation at around 30,000.
Of course, there are some outliers. For example, a Tesla Solar Roof may cost as much as 70,000 or more for full roof installation, while the budget-friendly SunTegra solar shingles may run closer to 20,000 for the entire roof.
While solar roof shingles cost substantially more than asphalt shingles. you’ll be producing your own electricity, therefore lowering your electric bills (or in some cases completely offsetting) by producing your own clean energy.
“A solar roof is a great and obvious way to reduce energy use and has the added benefit of being environmentally friendly,” said David Snyder, CEO of Nova Home Buyers, LLC.
If you go solar, you’ll also be eligible for solar financial incentives and rebates, like the 30% federal tax credit and net metering credits.
How to Calculate the Cost of Your New Solar Roof Shingles
As discussed, BIPV solar shingles are priced per watt. So to calculate the cost of your solar shingle roof, you’ll need to know how much solar power you need to power your house.
The only way to know the exact cost of your solar roof is to get a professional estimate, but you can calculate it yourself by walking through the follow the following steps:
- Find out how much energy your home consumes (typically found on your energy bills)
- Assess your roof space and the amount of sunlight your home receives
- Figure out the average system size in your area to estimate necessary system size (you can also use our solar calculator to find an estimate)
- Check the wattage of the shingles you intend to purchase
- Divide the required wattage of your system by the solar panel wattage
The average U.S. home needs a solar system that produces 9,000 watts (or 9 kilowatts) to completely offset their utility bills. With the cost of solar shingles ranging between 3.50 and 8.00 per watt, a 9,000-watt solar shingle installation would range from 31,500 to 72,000.
But don’t let those numbers scare you. Remember, your solar shingles don’t need to power your entire home.
Having a roof that produces any amount of clean energy can still significantly reduce your energy bills and your carbon footprint, making it much more impressive than a regular roof made of asphalt.
The Cost of Solar Panels: Is It Worth It?
Do the benefits of solar panels outweigh their costs?
Nathaniel Riley brings 28 years of experience in financial services, including merger-arbitrage trading, hedge funds, and alternative investments.
Somer G. Anderson is CPA, doctor of accounting, and an accounting and finance professor who has been working in the accounting and finance industries for more than 20 years. Her expertise covers a wide range of accounting, corporate finance, taxes, lending, and personal finance areas.
Skylar Clarine is a fact-checker and expert in personal finance with a range of experience including veterinary technology and film studies.
What Is Solar Power for the Home?
Homeowners who install solar power systems can 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 expensive.
- 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
In principle, working out whether it makes financial sense to install solar power for your home is simple. You will need to calculate:
- The cost of a solar power system
- How much energy it will produce
- What you would otherwise pay for the same amount of energy
- How many years it will take for your upfront investment to pay for itself in saved energy costs
- Whether the system will pay for itself in five years
If it does and you have the upfront capital, it’s probably a great idea. If you’ll have to wait longer for savings or take out a loan to afford the system, you’ll need to think the decision through carefully.
In practice, however, things are not this simple. There is a large variation in each of these factors, and that can make the costs and benefits of installing solar power for two homes—even if they are neighbors—radically different.
There are some tools that can help, though. Solar Reviews offer a calculator that will quickly provide you with representative costs and savings for a solar power system in every part of the U.S. Calculators like this are a good place to start if you are new to solar energy and want to understand the basic cost model.
In the rest of this article, we’ll take you through each of the key factors you should consider when calculating the costs and potential savings of solar power for your home.
Before getting solar panels, get quotes from several reputable installers to compare.
The Cost of Solar Power for Homeowners
First, let’s look at the cost of installing a solar power system for your home. The average, upfront cost of a residential solar power system is between 3,500 and 16,000.
Why the huge range of costs? Well, a lot of the variation depends on the size of the system you’d like to install and the type of panels you want to use. Whatever system you use, keep in mind that 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.
There are some additional costs, as well. 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.
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.
Calculating Your Energy Production
The second factor you’ll need to consider in your calculations is the amount of energy your system will produce and when it will do that. This can be a very complicated calculation to make, even for experienced solar engineers. However, let’s run through the basics.
One of the most important considerations is the solar irradiation levels available in the home’s geographical location; in other words, how sunny it is where you live. 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 and the tools on its website provide detailed solar information for specific locations within the U.S.
Equally important is your 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.
And then you must factor in the size of your system. 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. 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.
How Much Will You Save?
Once you know how much a solar power system will cost upfront, and how much energy it will produce, you can (theoretically) predict how much you can save in energy costs per year.
This is another tricky calculation, however, because a lot depends on how you pay for electricity at the moment. 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.
For some homes, it might even be possible to make money by selling solar power back to the grid. 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.
Calculating Solar Power Costs
At this point, you will be in a position to make a final calculation, and an assessment of whether solar power makes sense for you.
The overall cost and benefit of 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).
However, 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 to 40 years. 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.
Is Solar Power Worth It?
Once you’ve worked through all of these calculations, you’ll likely end up with a single number—the number of years it will take for a solar system to pay for itself in savings from your energy bills. If you live in a sunny part of the country and have high utility bills at the moment, you could be looking at a system that will reach this point in five years. Other homeowners may have to wait 10 or 20 years to reach this point.
In other words, most homeowners will eventually see a benefit from a solar power system; it might just take decades for this to be realized. Whether it is worth installing such a system therefore often comes down to a number of much less technical factors than those we’ve listed above: how long you are going to stay in your home, the subsidies available in your area, and simply whether you want to do your bit for the environment.
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 may be more important to you than a purely 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 are 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
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—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. If net metering is in place, you could reduce your bills even further.
How Much Does a Solar Panel Cost?
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.
How Long Will It Take To Recoup the Initial Cost?
Depending on where you live and the size of your system it can take, on average, anywhere from 10 to 20 years to break even 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.