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Roof photovoltaic panels. Tesla Solar Roof

Roof photovoltaic panels. Tesla Solar Roof

    Is My Roof Strong Enough for Solar Panels?

    Installing a solar system on your roof is a great way to take advantage of underused space. While roofs provide the obvious benefits of keeping us safe and dry, we can’t use them for much else. With a solar system, however, you can use the space to create cost-free and emissions-free electricity.

    If you’re considering installing a solar system, you may be questioning whether or not your roof can actually support the additional weight. That’s a valid concern, and we’re here to help.

    How Much Do Roof-Mounted Solar Panels Weigh?

    When it comes to the exact weight of a solar panel, it will vary from brand to brand and model to model. While solar panels are not extremely heavy, they’re built solid to withstand all kinds of environmental pressures.

    Most 60-cell PV solar panels are somewhere in the range of 35 to 45 pounds, with the majority settling around the middle of this range at 40 pounds. This weight is spread out over the full surface area of the panel. At roughly 5.5 feet by 3.25 feet, a solar panel ends up being around 2.3 pounds per square feet.

    roof, panels, tesla, solar

    72-cell panels will weigh a few more pounds, but because the weight is spread out over a larger surface area, the weight-per-square-foot is about the same. The average weight of a 72-cell solar panel is just over 50 pounds. With a rough dimension of 6.6 feet by 3.25 feet, which ends up being 2.4 pounds per square feet.

    Typically, either 60-cell or 72-cell solar panels are used for residential solar installations, but only 72-cell panels will be used on commercial installations.

    At Paradise Energy, we offer our customers three brands of solar panels we’ve found to be the best combination of performance, quality, manufacturer warranties, and cost. These panel manufacturers are AXITEC Solar, Hanwha Q CELLS, and LG Solar. Here’s a quick look at how much these manufacturers’ 60-cell and 72-cell solar panels weigh:

    LG Solar offers the lightest options and they are among the industry leaders in efficiency and quality. However, they will be one of the more expensive options.

    In addition to the solar panels themselves, there will also be mounting equipment installed on your roof to ensure the panels stay in place. This racking adds a small amount of weight to the solar system.

    Can Your Roof Support the Added Weight of Solar Panels?

    In the vast majority of solar installations, let’s say 95%, the existing roof can adequately handle the additional weight of the roof-mounted solar system.

    However, we need to be sure your roof falls within that 95%. To do this, a third-party architect or structural engineer will evaluate your building and the solar system that’s been designed for your property. If they find that the roof can adequately support the weight of the panels, they’ll provide a certified letter stating their approval.

    If they find that the roof cannot support the added weight, they’ll recommend what changes need to be made in order to safely install the panels. These could include things like repairing or replacing the roof or adding additional support to the rafters or beams

    You and your solar installer will review these changes to see if they fit your goals for the project. If they do, the changes will be made and the revamped structure will be reevaluated. If the structural engineer deems the structure safe, they’ll give their letter of approval and the solar installation can start.

    How a solar roof works

    Tesla introduced its solar roof in 2016, shaking up the solar industry forever. But how does a solar roof work?

    The Tesla roof uses tempered glass shingles to replace all the standard shingles on your home’s roof. Some of these shingles are also solar panels, meaning that nearly every inch of your roof could, in theory, generate electricity.

    Because most roofs have a few spots that don’t get much sunlight, Tesla Roofs also include a few inactive panels. These look the same as the solar shingles but don’t produce energy, which helps to keep down the cost of installation and saves resources.

    Tesla Roofs are the only full solar roof currently available, but they’re not the only option for going solar without solar panels. In fact, the first solar shingles were brought to market in 2009 by DOW Company, and several other companies also make solar shingles.

    roof, panels, tesla, solar

    What’s the difference? Solar shingles are just that: shingles. They’re designed to either integrate with your existing or new roof shingles or tiles or to sit on top of them. Either way, the look isn’t quite as seamless as a full Tesla Roof.

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    The benefits of a solar roof

    There are many benefits to going solar, and solar roofs and shingles offer all these and more.

    The look

    Solar roofs provide all the benefits of a rooftop solar array without dramatically changing the appearance of your home. That’s because solar shingles are designed to look as much like regular roof shingles as possible. Most solar shingles can be integrated into an existing tile or shingle roof, or can be laid over top as a sort of second skin for your roof. Even if they’re attached on top of your roof’s regular tiles, the profile of solar shingles is a lot lower than with mounted solar panels.

    With a Tesla Roof, all the tiles look the same, regardless of whether they’re active solar shingles or inactive tiles. This makes a solar roof or solar shingles a great fit for homeowners who don’t like the look of more conventional solar panels. A solar roof may also enable homeowners to benefit from solar without invoking the ire of homeowner associations.

    Cost-effective roofing and solar combined

    A new roof can be a costly proposition, as can a solar installation. What if you could combine the two and save some cash?

    If your roof is due for an upgrade, consider a solar roof. Sure, it will cost more than a regular roof, but it will typically cost less than a regular roof plus a conventional solar array with similar power output.

    A high-performance roofing solution

    Worried that a solar roof won’t be as good as a regular roof? There’s no need for concern. These roofing shingles perform just like regular shingles, only they produce electricity while keeping your home watertight and safe from the elements.

    The key here is that solar shingles combine solar cells with the roof sheathing. In more conventional solar arrays, solar modules are mounted on top of shingles (or other roofing material).

    Effective use of space

    Solar shingles can be a great way to go solar if you have a small roof that makes a standard solar set-up difficult or even impossible. For the same reason, solar shingles can be a good choice for a roof with awkward space constraints, such as dormers, skylights, and so forth.

    After all, a shingle is far smaller than a solar panel. This means you can squeeze a few shingles onto a small area and maximize your rooftop real estate. You might even decide to skip your rooftop entirely and instead install a solar roof on your garage, shed, or an auxiliary dwelling, especially if these get more sun exposure than your home.

    No external wiring

    Standard solar panel installations require external wiring that connects the mounted solar panels to the inverter and main service panel inside your home. With a solar roof and most solar shingles, all the wiring is internal and hidden. This reduces the risk of damage from wind, rain, birds and other wildlife, and so forth.

    Standard solar arrays also have to be mounted on top of roofing material, which usually means drilling into the roof. Some metal roofs allow for solar modules to be clicked into place, but regular roof shingles and tiles require solar installers to penetrate the roofing material, which can cause damage and create weak spots.

    These problems are unlikely if you use an experienced and skilled solar installer, but they’re still a risk with regular arrays.

    Some solar shingles are direct to deck, acting like both a solar panel and a roofing shingle. Others attach to existing roofing shingles or tiles. As such, the potential for damage to an existing roof varies greatly between differing solar roofing options.

    Easier to repair and replace

    Another key benefit to solar shingles is that they’re lightweight and relatively easy to repair and replace. If one or two get damaged, you can quickly replace these with fresh solar shingles or inactive shingles as needed. It’s much harder and more costly to replace or repair an entire solar panel.

    Solar shingles are also built to withstand rain, snow, and wind. And if something does go wrong, most companies offer a good warranty, so you can get your shingles replaced for free. Tesla even offers a lifetime warranty for its physical shingles, which is great if you’re planning on staying in the same home for a long time. If you think you’ll move home in the next 25 years or so, though, that lifetime warranty might not be all that useful, given it’s hard to take your solar roof with you (unlike solar panels).

    Are there any downsides to solar roofs?

    So far, so good, but what about the disadvantages of solar roofs?

    Cost and efficiency

    As discussed, solar shingles aren’t cheap, despite being more cost-effective per watt. Compared to the price of a standard rooftop solar installation (15,000 to 40,000), the Tesla solar roof has been reported as ranging from 30,000 to nearly 100,000. What’s more, Tesla has shifted its dramatically, and without warning, several times, catching customers off guard. Tesla also now insists that solar roof customers buy the Tesla Powerwall battery, which raises the cost even more.

    Tesla isn’t the only name in town, though, and you definitely pay a premium for the brand.

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    High-efficiency shingles from other companies tend to be less expensive and just as efficient as Tesla’s shingles, but they’re all less efficient than the best solar panels. In general, a solar shingle typically produces between 13 and 63 watts. They need high sun exposure and a good slope to meet their maximum output, though.

    Why are solar shingles less efficient than solar panels?

    The main reason is that building-integrated solar panels (BISPs, or BIPVs) don’t typically allow for air to circulate underneath, which means they overheat quickly, which impairs electricity production.

    This lack of efficiency combined with higher upfront costs can mean a longer payback period for solar roofs. In fact, solar roofs don’t offer anything like the return on investment of a standard solar array, unless you’re in need of a new roof anyway.

    Lifespan and flexibility

    Solar roofs and shingles also have a shorter lifespan than most regular solar panels. While a standard solar panel can usually keep producing electricity at around 80% of original output for 25 years or more, solar shingles usually maintain that level of output for just 20 or so years. They also produce less electricity to start with.

    One other downside of a solar roof is that it can be hard to take with you if you move. Unlike solar panels, solar roofs are custom-made to fit your home. Solar shingles or DecoTech integrated panels may be able to go with you if you move, depending on the type of roof at your new home.

    Other downsides to solar roofs

    While solar roofs are increasingly popular, you might not be able to find a skilled installer in your area. In contrast, conventional solar installers are easy to find, which also means the labor cost of an installation is typically lower than for a solar roof.

    The same goes for solar shingles. While there are more installers for these than for Tesla Roofs, it’s still very hard to find a credentialled installer in most places, especially if you live outside of a big city.

    Finally, you’ll want to consider the environmental cost of installing a solar roof. Chances are you’re interested in these products because you want to live a greener lifestyle. Sending your current, perfectly respectable roof to a landfill just so you can install a solar roof isn’t very sustainable.

    Understanding Solar Roofs vs Solar Panels

    • A solar panel–also called solar cell panels, solar electric panels, or photo-voltaic (PV) modules–is a group of cells that make energy from sunlight–all mounted together in a framework, called a panel. Homeowners then install these panels on top of their roof.
    • A solar roof goes a step further by using materials in the roof’s construction that can absorb sunlight directly rather than installing panels on top of an existing roof. The term “solar roof” may refer to an entire roof or just a section.

    Most people today have some familiarity with solar panels, whether on camping equipment or on rooftops. Believe it or not, the first rooftop solar panels, connected directly to a building’s roof, were installed in the late 1800s.

    The first solar roof appeared almost a century later, in 1973. Innovators at the University of Delaware integrated solar cells into the roof instead of putting them on top.

    Since then, the solar energy industry has evolved considerably. Now that we understand it as a viable, sustainable energy source, today’s consumers seek the best ways to leverage solar and other renewable sources to meet ever-increasing energy demands.

    The comparison below explains some features of solar roofs vs solar panels that can help you harness a virtually endless energy supply from the Southern California sun. It also offers some tips to help you decide which option best suits your needs.

    What is a Solar Roof?

    Simply put, the difference between a solar roof and solar panels is the relationship of whole (roof) to part (panel). Solar roofs are constructed with integrated materials that convert sunlight into electrical power, rather than placing panels on top. The integrated solar energy cells may be part of a building’s initial construction, or function as a later, post-construction upgrade.

    Homeowners may upgrade to a solar roof if they discover the original structure needs replacing, or simply because they want to save money on utility bills while simultaneously increasing their home’s value.

    While solar panel installations can look like obvious additions, solar roofs appear as seamless elements of architectural design. Homeowners concerned with improving solar energy’s aesthetics proved to be a factor in driving the industry’s growth.

    Although typically thin, solar roofs are quite durable and resilient against harsh weather. In and around San Diego, they also tend to shine, as they’re commonly made of materials like gallium, indium, selenide, and copper. Several different types of solar roofs are listed below.

    Types of Solar Roofs

    A solar metal roof looks just like those on metal buildings. They contain several layers with a solar cell layer–including tempered glass–on top. With invisible wiring or connection hardware and a variety of available colors, you can select a metal roof that complements your home’s appearance.

    This roof type features sections of solar panels that replace traditional roofs of asphalt shingles or clay tiles. Without roofing materials beneath, the solar panels interlock to keep out air, water, and debris.

    Solar shingles, which look similar to other roofing shingles, are a popular choice. Their hidden wiring and connections give them a sleek appearance. Monocrystalline shingles–made from silicon–offer the highest efficiency.

    The initial cost of installing a solar roof will likely be much more expensive than installing solar panels to cover a comparable size.

    The advantages of a solar roof include significant added home value, lower electricity bills, and rebates and/or credits. Added together, these benefits can easily outweigh your installation investment.

    Solar Panel Advantages

    Solar panels, which are more well known, have more practical advantages and lower costs than solar roofs.

    • AdjustabilityPanels can be angled to maximize insolation and energy efficiency.
    • PortabilitySolar panels can be removed and reinstalled, although this option is not usually advisable, especially if the installation company lacks sufficient experience.
    • AffordabilitySolar panel installations are typically less expensive than solar roofs, if no roof work is required. However, if you know your roof will require repairs in the near future, plan on scheduling them before installing solar panels.

    How to Choose Between a Solar Roof vs Solar Panels

    One of the main reasons homeowners choose a solar roof instead of solar panels–once they have confirmed that solar panels will work on their roof–is their aesthetic appeal.

    While choosing between solar roofs vs solar panels can be difficult, answering the questions using the table below can help you make the best selection.

    These suggestions weigh the strengths and weaknesses of both options to help you decide when to consider installing a solar roof, solar panels, or both.

    Before committing to any kind of solar installation, make sure to consult with an experienced company that can give you specific, detailed answers about using solar energy sources. You need a company that can obviously perform the installation to the highest standards, but will also be there to support you in the future.

    Baker Electric Home Energy has served the Southern California area for over 15 years and provided clean energy solutions to more than 17,000 of your neighbors. Our way of doing business, The Baker Way®, which includes delivering extraordinary service and building customer confidence, is exemplified by being awarded the Torch Award for 2021. For more information on whether to go with solar roofs vs solar panels, contact us.

    What Is the Best Roof Design for Solar Panels and What If Mine’s Not Perfect?

    If you’re looking to go solar at home, chances are you’re going to put those panels up on your roof. Ground-mounted solar is a great option, but it’s uncommon to have enough space to put up a decent-sized system in your yard. So that begs the question, what is the best roof design for solar panels?

    Let’s get this out of the way first: Almost no one has the perfect roof for solar. Although some roof shapes and angles are better for solar production than others, solar panels are extremely versatile and can provide energy cost savings and carbon footprint reduction in a wide range of configurations.

    In other words: Don’t let perfect be the enemy of good.

    In this article, we’ll explore that makes a good roof for solar panels and some frequently asked questions.

    roof design traits that effect your solar production

    There are several roof characteristics that effect how much your solar panels will produce. Here is the top six:

    Orientation

    Also known as azimuth, orientation is the direction your roof faces. For North American solar systems, the best roof design for solar panels is one with a large, unshaded south face (an azimuth of 180 degrees).

    Not having a south-facing roof is not a deal-breaker. However, many roofs are multi-faceted, and if your roof is mostly west- and east-facing, you’re likely to only see a 10-20 percent reduction in the amount of energy you’re generating.

    There’s been an ongoing debate about south-facing vs. west-facing panels over the last couple of years. While south-facing panels will generate the most energy, west-facing panels generate the most energy when demand is highest. That’s why some big proponents, including the California Energy Commission, encourage builders to include some west-facing solar panels in their developments.

    In the end, south is best, but west and east are also good; having panels facing south and west will help you generate energy throughout the day.

    Size

    Along with orientation, the size of your roof will determine how many solar panels you can install. The average US home solar system size is 5 kilowatts or 12-13 panels with a rating of 400 Watts. With solar panels requiring about 15 square feet each, you need about 200 square feet of (south- or west-facing) roof space to fit 13 panels on your roof.

    Shade

    Big surprise: Solar panels only work when the sun is shining directly on them. If you’re surrounded by tall trees and your roof and yard are shaded most of the day, your choices are limited to either:

    • Taking down trees
    • Buying clean energy from a community solar system instead
    • Opting for a clean energy mix from your utility (if available)

    It’s important to note that shading doesn’t always come from trees and outside objects — sometimes roofs can shade themselves. The best roof design for solar panels is one with minimal tiers and overhangs that could cause shading.

    Material

    What is your roof made of? The most common type of roofing material is asphalt shingles, but solar installers can put panels on just about any of the most common types of roofing materials, including tile, metal, slate and even wood shingle.

    Some roof types are more difficult to install on than others, and if your roof is made of trickier materials it may add to the cost of your solar installation.

    Age

    important than the roof type you have is how old your roof is. According to a study by the National Home Builders Association, an asphalt shingle roof should last for around 20 years, while slate, copper, tile, and metal roofs can last 50 years or more. Meanwhile, most home solar systems are guaranteed to last for 25 years, and will likely last much longer.

    So if your roof will need to be replaced in the next 10 years or less, consider doing so before your solar panels are installed. You can always replace the roof after your panels are in place, but it involves removing the panels and racks, replacing the roof, and then re-installing the panels, which adds more cost to the project.

    Pitch

    The slope of your roof isn’t as important as the orientation, but it can affect your solar energy output. The ideal roof angle for power generation is about 30 degrees, but roofs that are too steep make installation difficult, while flat roofs mean that you can set the panels at just the right angle, but you’ll be paying extra for the required racking.

    As a rule of thumb, your panels should be tilted at about the degrees as your latitude. So if you live in Los Angeles at 34 degrees north, then your panels should face south and be tilted about 34 degrees.

    What if I don’t have the best roof design for solar panels?

    Not everybody has a large, unshaded, south-facing roof. So what happens if your roof design is less than perfect for solar panels?

    In these scenarios, there are two ways to increase your solar output:

    Use panels with a higher power rating – Solar panels are rated from 250 to 450 based on how many Watts of DC electricity they can produce per hour. So, if you don’t have enough space for 16 250W panels, then you can achieve the same output with 10 400W panels.

    Increase the number of panels – If you have limited sun exposure due to shading, pitch, orientation, or location you can simply add more panels. For example, Los Angeles averages around 6 peak sun hours per day while New York City averages around 4.5. That means it would require 15 panels to achieve 27,000 kWh per day in New York City, and around 11 panels to achieve 27,000 kWh per day in Los Angeles.

    In both cases, you can expect your project to cost a little more than if you had a perfect roof for solar. However, the solar panels themselves make up a small fraction of your project cost, and adding or upgrading will have little effect on your energy cost savings over 25 years.

    roof, panels, tesla, solar

    Best roof design for solar panels FAQs

    What type of roof is best for solar panels?

    A south-facing composite asphalt shingle roof with plenty of space is typically considered the best roof design for solar panels. However, solar systems can be very versatile and provide clean energy and cost savings in a wide variety of applications.

    What is the best roof design for solar?

    It may sound simple, but a large square roof with a standard pitch between 20-30 degrees is ideal for a simple solar system. Roofs with lots of tiers with little extended space can create challenges for designers and installers.

    What type of roof is not good for solar panels?

    We hate to be the bearer of bad news, but if you have a slate or wood roof, your options are limited. Many solar companies will refuse to install on these materials, which can limit your options.

    Some work-arounds include re-roofing with a new material or installing the system on the ground.

    What if my roof is old?

    Most roofs must be replaced at some point, but you have a couple options when assessing your roofs current state before going solar. If your roof is too old, some solar installers will replace your roof as part of the same project, which can help you save by combining the projects.

    If your roof is getting old but not quite at point of replacing, it may be worthwhile to install the solar panels knowing you’ll need a roof replacement at some point down the road. In this case, re-roofing requires the added cost of having your solar company un-install and re-install the panels.

    Solar panels can help aid the longevity of your roof, because they help protect against a lot of nature’s elements.

    Will my roof have issues with leaks?

    Leaks after solar installation are extremely rare. Yet, if they do happen it’s important to be covered by a warranty. Good installers offer extended warranties on workmanship, which means you won’t have to worry about being on the hook for any issues that could arise during an install.

    If your roof seems like a fit, use Solar.com to receive free, no-obligation bids on a solar installation for your home.

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