What are solar roof tiles?
Solar shingles, also known as photovoltaic shingles, solar roof tiles, are solar
panels that are designed to look like and function as conventional roofingmaterials, like asphalt shingle or slate, but at the same time, they produce electricity. Because of this, they are considered as a type of solar energy solution known as building-integrated photovoltaics (BIPV).
Solar shingles come in various shapes and kinds. Some of the most popular kinds include the shingle-sized solar panels that take the place of conventional shingles in a strip, semi-rigid designs that contain several silicon solar cells that are sized more like conventional shingles, and newer systems that use various thin-film solar cell technologies that match conventional shingles both in size and flexibility.
Despite the years of development that they took, solar shingles only became commercially available in 2005. But even though that is the case, there are already several companies that manufacture solar shingles. The three main manufacturers of solar roof shingles are RGS Energy, SolarCity, and CertainTeed. There are other active manufacturers.
For example, Tesla has their own version of solar shingles, which is called the Solar Roof. And SunTegra Solar Roof System and Atlantis Energy Systems also manufacture solar shingles of their own design.
History of solar roof tiles
Solar shingles share the same developmental history as solar panels. In other words, its developmental history can be traced back to 1908 when the idea for creating photovoltaic cells, which are the building blocks for all solar technology, came to be and initial ventures for solar technology began. In addition to that, the technology behind solar shingles was patented back in the 1970s.
However, people only came to know about solar shingles when solar shingles became commercially available back in 2005. This was when Dow Chemical Company revealed their new roof shingles that also doubled as solar panels, which they named the POWERHOUSE Solar System. In a 2009 interview, a spokesperson for the company hypothesized that their entry into the solar shingle market would generate $5 billion in revenue by 2015 and $10 billion by 2020.
But in 2016, Dow ended up dumping the project and selling their POWERHOUSE product line to RGS Energy in 2017. As of right now, the RGS POWERHOUSE line continues to live on in its 3rd generation iteration.
How Solar Roof Tiles Work
Simply put, solar shingles work like traditional solar panels in that they also make use of the sun as an energy source to generate electricity. Each cell on the solar shingles has semiconductors that capture the sunlight once it hits the shingles. Once the semiconductors have captured the sunlight, an electron from a light particle is knocked off. And this freed electron travels through an electrical circuit to an area where the other electrons are stored, thus finally generating a current that can be used for electrical power.
Solar shingles can allegedly power anything, from a small calculator to a tall skyscraper. Additionally, they are also reported to be able to produce 100% of a building’s electricity usage. However, the second point is still debatable because there are various factors that affect the efficiency of solar shingles on buildings. These factors are the demand of a building, the amount of sunlight the building gets at that particular location, the building’s current utility rates, and the availability of sufficient space on the roof that opens to southern skies.
However, despite all of that, solar shingles are still highly efficient since they can be placed anywhere, even in places that aren’t particularly sunny. This is because solar shingles can use diffused and scattered sunlight on overcast or rainy days. Moreover, if the building is located in a place that is exposed to a lot of sunlight, then the solar shingles can produce excess energy that will be sent to the electrical grid. Basically, no matter what the climate is like in a particular geographical location, solar shingles are still efficient.
Technologies used in Solar Roof Tiles
Some of the early manufacturers of solar shingles made use of solar thin-film technologies, such as a copper indium gallium selenide (CIGS) solar cells which are less common in the solar industry than silicon-based cells. However, as of right now, manufacturers are already choosing to use the industry-standard monocrystalline or polycrystalline silicon solar cells.
As for the installation methods, some solar shingle solutions can be easier than traditional panel installations. This is because solar shingles avoid the need to locate rafters and install with a process much more similar to asphalt shingles than standard solar panels.
How Solar Shingles Look Like
Most solar shingles come in 12 in x 86 in (300 mm x 2,180 mm) and can be stapled directly to the roofing cloth. When applied, they have a 5 in x 86 in (130 mm x 2,180 mm) strip of exposed surface. Different models of shingles have different mounting requirements. Some of them can be applied directly onto the roofing intermixed with regular asphalt shingles while there are others that may need special installation.
A lot of the times, solar shingled roofs have a deep, dark, purplish-blue, or black color. As a result, they tend to look similar to other roofs in most cases. In particular, Tesla Solar has developed shingles that come in several styles so as to better match traditional roofs. And in 2018, the company started offering in slate and Tuscan styles. This tendency for manufacturers to make solar shingles resemble roofs is because of the fact that homeowners tend to avoid having large panels on their roofs.
Solar Roof Tiles Maintenance
Because of the fact that solar shingles look like traditional roof tiles, their maintenance is actually really simple. Understandably, homeowners still need to look out for snowfall and leaves. But other than that, they won’t need specialized equipment to clean the shingles. It is enough to use a typical garden hose.
Long story short, solar shingles don’t need that much maintenance. In fact, some people would even argue that even without any maintenance at all, solar shingles can still last between 25 and 30 years.
Cost of Solar Roof Tiles
Unlike the typical roof shingle and solar panels, solar shingles have a dual purpose: to act as both a roof and a solar panel. Because of that, it can be expected that their price is going to be expensive.
Regular roofing materials typically cost around $80 to $375 per square. In other words, it is estimated that most homeowners would spend between $5,000 and $10,000 to install a roof using the regular roofing materials.
On the other hand, the cost of solar shingles varies depending on how the manufacturer chooses to price it — whether it’s per watt or per square. Usually, per watt is the standard pricing method, and the cost can range from $3.80 to $9. As of May 2019, the average cost of a traditional, roof-mounted residential solar panel installation in the U.S. is just above $3 per watt, according to the Solar Energy Industry Association. This shows that solar shingles are more expensive than both regular roofing materials and solar panels. But even though that’s the case, some companies in recent years have made efforts to lessen the gap between the installed cost of going solar with panels versus going solar with shingles.
According to Dow Chemical Company reports, a typical residential install that consists of 350 solar shingles can cost at least $20,000. Moreover, according to Tesla, their solar roof will cost $21.85 per square foot, and so, if a home with 2,000 square feet of roofing were to install solar shingles, that would cost about $44,000. This all seems quite costly, but federal and state incentives depending on the location might be able to significantly bring down the cost.
Solar contractors usually offer homeowners a full-service price for solar installation, which includes equipment purchasing, permit preparation and filing, registration with the local utility company, workmanship warranties, and complete on-site installation. Additionally, because photovoltaic solutions produce power in the form of direct current (DC) and the standard in homes is alternative current (AC), all grid-connected solar installations include an inverter to convert DC to AC.
Solar Incentives and Tax Credits
Currently, the U.S. federal government provides a $2,000 tax deduction for homeowners to put a PV device and another $2,000 credit if they in solar hot water or a solar thermal unit. Aside from that, some states and local jurisdictions offer even additional incentives. And since solar shingles are considered to be a PV device, all these solar incentives and tax credits can be applied to them.
Availability: Top Solar Shingle Brands
Tesla Solar Roof
Tesla Solar Roof isn’t really the first solar shingle brand, but it is the one that launched the popularity of solar shingles. The primary reason why Tesla was the one that brought back the popularity of solar shingles is because of their innovation on the product. Unlike the other companies before them, Tesla has made sure that their solar system is a roof first. And since the idea of a complete solar roof has not yet been successfully brought to market, it was quite a feat that Tesla was able to achieve that.
The Tesla Solar Roof costs at around $21.85 per square foot. So, if a house has about 2,000 square feet of roofing, then the homeowner would need to pay roughly $44,000. In addition to that, the Tesla solar shingles are made up of quartz, and they come with four available designs: Tuscan glass tile, slate glass tile, textured glass tile, and smooth glass tile.
CertainTeed Apollo II Solar Roofing System
CertainTeed is a North American company that specializes in the manufacturing of products for roofing, insulation, wallboard, and more. Currently, they have two solar products under their Apollo line. The first is Apollo II, which is a shingle that is applied on top of an existing roof, and the second is the Apollo II Tile, which is a replacement tile just like the Tesla Solar Roof.
CertainTeed uses monocrystalline silicon solar cells for their Apollo products. They also don’t use glass louvers or hydrographic printing, and the products don’t have a variety of appearances that allow them to mimic conventional high-end roofing products such as slate. As a result, the CertainTeed Apollo II isn’t as aesthetically attractive as their competitors.
However, even though that is the case, the Apollo tiles still have their own attractive qualities. For one thing, the Apollo tiles sit flush on top of your existing roof, unlike the solar panel where there will be several inches of air space between the back of the panel and the roof. Aside from that, in terms of size, the Apollo product is approximately 47 in x 17 in, and it has an STC rating of 63 watts and a PTC rating of 53.5 watts.
Luma Solar Roof
Just like Tesla, Luma Solar offers a complete roof replacement product that is simply named the Solar Roof. And these solar roof replacement products include both non-solar and solar cell components that give the roof a more uniform appearance than the solar-only shingles offered by other companies such as CertainTeed.
Aside from that, Luma Solar also offers their PV shingles as a standalone product that can be mixed with conventional roof shingles. Each of their shingles has the dimensions of 54.37 in x 15.62 in and is made up of polycrystalline cells to generate 60 watts.
RGS POWERHOUSE 3.0
The POWERHOUSE line of solar shingles actually started out as a Dow Chemical product that was based on thin-film solar. After Dow stopped producing solar products back in 2016 and RGS Energy bought the product line, the first change that RGS Energy implemented onto the POWERHOUSE line is to use monocrystalline cells instead of thin-film.
Similar to the CertainTeed Apollo Tile, POWERHOUSE is a roofing shingle that can be used instead of the conventional asphalt shingle. The dimensions of one shingle are 41.6 in x 31.5 in, and each of them generates 60 watts. Additionally, RGS reports that the efficiency of each cell is 17.1%.
Unlike the Tesla Solar Roof which has a lot of designs, POWERHOUSE only comes in one style — an all-black appearance just like the Apollo Tile. This design allows the solar cells to be clearly visible when viewed from above but not apparent when viewed from street level.
SunTegra Tile and Shingle
A New York-based solar products company, SunTegra offers two solar roof products. The first is their Shingle, which is mounted on top of your existing asphalt shingles, and the second is their Tile, which is the replacement for concrete tile products. Both of these products are offered with PV-option only. Basically, both the SunTegra Shingle and Tile are intended to be integrated alongside conventional roofing shingles or tiles.
The SunTegra Shingle is somewhat different from the other solar shingles considering that it is larger than asphalt shingle. To be specific, the SunTegra Shingle measures at 52 ⅝ in x 23 ⅛ in. This because the Shingles sit on top of the roof and do not replace your existing shingles. Additionally, the Shingle is also very low-profile as it only measures ¾ inches high. Because of that, SunTegra has incorporated an air channel on the backside of the module, thus keeping the panel cooler and improving efficiency.
Exasun X-Tile and X-Roof
A company based in the Netherlands, Exasun offers multiple solar products. Two of which are solar-roof-related: the X-Tile which resembles a terracotta tile that can be laid in place of roof tiles, and the X-Roof, which is a complete roof replacement.
The Exasun X-Tile is based on its back-contact-on-glass technology and equipped with a suspension system for quick assembly. It has a high-efficiency rate of 18-18.6% as well as a high-performance ration of 4-7% more kWh/kWp.
Meanwhile, the Exasun X-Roof system consists of small X-Glass panels of 60 cm by 82 cm. These roof panels are attached to the roof in seconds with an innovative but simple mounting system. These panels also have great ventilation behind them, optimally cooling them for a high-performance ratio. Moreover, the X-Roof is also perfectly perfected against rain, hail, and any other extreme weather conditions.
Forward Solar Roofing
Forward Solar Roofing is a startup that used a Kickstarter campaign to develop their solar roofing projects. The company actually intends to make their solar shingle line similar to the Tesla Solar Roof in that it is a whole-roof replacement product. In addition to that, the Forward Solar Roof also includes PV and non-PV components for a seamless visual appearance — just like Luma Solar.
As of right now, they have two styles in development: Metal, which resembles a steel roof, and Tile, which resembles terracotta. In the future, Forward aims to have eight colors available for their products.
Based in San Francisco, Hanenergy is a solar company that specializes in thin-film solar. The HanTile product aims to look like a dark terracotta roofing tile, and it also integrates thin-film PV. There is not much information available for this product considering that it is still in the development process.
Sunflare has been in the business of PV design and manufacturing since 2009. Ever since the company’s establishment, they have offered a wide array of PV products: from parking retrofit systems to semi-rigid products for large-scale ground-mount installations. Their most popular product is most likely their flexible solar panels that are designed for rooftop installations. These panels stick to roofs without any need for mounting hardware or roof penetration.
Even with their wide assortment of products, Sunflare still aims to branch out. And this time, they plan to get into the residential solar shingle market. As a result, they’re currently working on developing on a new line that will be similar to the other BIPV options. Sunflare plans that these solar shingles will not be adhesive but instead will be applied using traditional roofing methods.
Just like the Hanenergy HanTile, not much information is available for this particular product. That said, Sunflare has made an announcement that they expect to release their solar shingle technology to the public in 2020.
The Installation of Solar Shingles
Installation example: Apollo II Solar Roofing System
Some Solar Shingles Reviews
Pros and Cons of Solar Shingles
The Future of Solar Shingles
It is quite difficult to determine what the future holds for solar shingles. This is because this technology has its own advantages and disadvantages, so making a valid hypothesis will be a difficult task.
On one hand, the solar industry is booming nowadays. With the urgency of a global action to combat against climate change heightened, people have started to turn to renewables like solar and wind as their primary source of energy. And because of that demand, solar products are selling really well.
However, on the other hand, solar shingles are having a hard time competing against their fellow solar product which the solar panels. This is because solar panels are a more mature and affordable technology, and so people tend to gravitate towards them instead of solar shingles. It also doesn’t help the fact that if a roof is in good shape, then installing solar shingles would be a needless expense. As a result, if homeowners really want to integrate solar into their house, solar panels just sound more practical for them.
Despite the fact that solar shingles aren’t that popular compared to solar shingles, there still remains a great deal of excitement around solar shingles. This is primarily because the solar industry keeps moving forward, and with the rise of BIPV technologies, solar shingles will just be able to help in launching this industry further.
Furthermore, even though solar panels dominate over solar shingles, there are some qualities that solar shingles have that the panels don’t. The first is the fact that solar shingles can replace panels in residential areas based on their aesthetic appeal. Solar shingles usually come in various designs and shapes while solar panels don’t. Aside from that, they are also a lot easier to install. With all these advantages, some people have even theorized that there is a possibility that solar shingles can replace panels in the near future.
As of right now, there is still a small number of solar shingle manufacturers. And that is why it’s a little difficult to estimate in a general way about how the market reacts to new solar shingle products or deals. But solar shingles seem to be thriving as of the moment and showing no signs of going away. With that, people can only guess that solar shingles will indeed rise someday. It will only be a matter of time.
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