Last Updated: Aug 4, 2021
When you ask most homeowners about the available options for integrating solar energy into their homes, the vast majority of people will likely respond that rooftop solar panels are their primary option. There are, of course, people who either do not own their home. Others live in multi-family condos or apartments. Many people have roofs that do not receive enough direct sunlight to make rooftop solar feasible. For these situations, participating in community solar programs, purchasing green power, or finding other solar-powered products (like solar grills) enable them to benefit from clean, renewable solar energy.
Recently, however, building-integrated photovoltaics (BIPV) energy is revolutionizing how homeowners can incorporate solar energy production into their homes. This short article takes an in-depth look at BIPVs to help you determine if this might be an option for a new home or a renewable energy retrofit of your existing home.
The main difference separating building-integrated photovoltaics from traditional solar panels can be easily summed up. Whereas solar panels are attached to the home (most often rooftops), BIPVs are built into the house's vital exterior elements. In this sense, BIPVs serve the double function of generating renewable energy for your home from the sun while also performing the necessary structural tasks of certain building elements.
The most common type of building-integrated photovoltaic product is solar shingles or solar roofing materials. Check out this complete RISE guide for more detailed information on solar roofing options for homeowners. Building-integrated photovoltaics officially got their start when the company Tesla began marketing their solar shingle in 2017. In the roughly four years since that launch, the variety of BIPV products continues to expand, and not just for your roof.
Essentially, anywhere that sunlight directly hits the exterior surface of your home, homeowners can potentially incorporate BIPV products into the building design. Companies that operate in the BIPV market continue to find ingenious ways to integrate BIPV products into the building envelope seamlessly. They can be part of standard building components such as façades, roofs, or windows. Though you could not generate electricity by placing solar panels on your home foundation, virtually anywhere that sunlight is present, you may be able to find a BIPV product to install.
BIPV products used to be exclusively for roofing. This feature makes sense since our roofs generally receive the most direct solar radiation. Most early innovators in BIPV technology focused on replacing traditional roofing with panels, tiles, or shingles that could generate renewable solar energy while protecting the home from the elements. The impetus for this innovation stemmed from a simple economic calculation. Suppose the average cost of a roofing replacement in the USA costs between $5,500 and $11,500. In that case, solar panels that doubled as a roof could essentially "subsidize" part of the cost of going solar.
More recently, companies have begun to look for ways to incorporate solar energy production in other traditional building elements. Today, homeowners can find BIPV products to "replace" the following building elements:
BIPV products are systems that can function as a component of the building skin or envelope while simultaneously converting solar energy into electricity by serving a dual purpose. Instead of attaching solar panels to a separate roof or façade, BIPV products can offer weather protection, thermal insulation, noise protection, daylight illumination, and even increased safety, along with an independent, clean source of renewable energy for your home.
According to one financial analysis, building-integrated photovoltaic products' total global market size will grow to an astounding $59.5 billion by 2028. As more and more companies rush to enter the BIPV industry, the market could see a compound annual growth rate of at least 20 percent! In practical terms, this means that the options for building-integrated photovoltaics currently available to homeowners and builders will only continue to expand. Prices should also continue to drop as competition stiffens and more innovative products become available. The combination of the plummeting cost of solar energy and innovative technologies in solar energy production (such as thin-film technologies, solar cell efficiency, open-circuit voltage, short circuit current, maximum effect, and fill factor) will almost certainly continue to drive innovation in BIPV products.
Across North American, there is a significant push for achieving net-zero energy use in our homes. The Energy Information Administration (EIA) states bleakly that natural gas (a fossil fuel) continues to be the primary source of electricity, accounting for 42 percent of residential sector end-use energy consumption in 2020. Petroleum was the next most-consumed energy source in the residential sector in 2020, accounting for 8 percent of total residential sector energy end-use. It is hopeful to see that coal is being slowly phased out for residential uses. Still, renewable energy sources such as geothermal, solar, and wood fuels together only account for about seven percent of the residential sector energy end-use in 2020.
BIPVs can play a significant role in helping to speed up the widespread adoption of renewable energies and help more and more homeowners attain net-zero energy use.
The exact amount of energy that BIPV products or systems can produce is contextual. The total amount of energy will depend on several environmental factors related to your home location, including:
Given the environmental factors mentioned above, many homeowners ask when considering BIPV systems: Will these systems produce nearly as much energy as standard solar panels? In the case of solar roofing or solar shingles, the answer is yes. Solar panels permit installers to tilt the individual panels to the optimum orientation to catch more sunlight. In contrast, solar shingles generally cover the total roofing area, thus making up for this slight difference in inefficiency. In many cases, a roof covered in solar shingles or another type of BIPV roofing should be able to provide the needed electricity for efficient homes to achieve net-zero energy use.
Because of proper orientation, other BIPV products such as solar facades and windows may be less efficient than solar panels. However, this will vary on a case-by-case basis. The south-facing façade of your home may be the best place to capture solar radiation if your roof orientation is not ideal.
In terms of generation efficiency, the case for BIPV systems is less straightforward. The darker BIPV panels such as those used for solar shingles or other types of solar roofing generally have comparable efficiency ratings to regular solar panels. However, the transparent or semi-transparent BIPV panels used on windows, skylights, and other similar surfaces continue to be significantly less efficient. Because these transparent BIPV products allow some solar radiation to pass through, the total generation efficiency might only be 50 to 75 percent as efficient as regular solar panels.
The primary appeal of BIPV products is twofold. BIPV systems increase the space on and around that home where you can turn solar radiation into usable energy for your home. More importantly, is the economic factor because BIPV products serve a double function. They provide renewable energy while also protecting the house, reducing the cost of autonomous solar energy generation for homeowners.
By using solar shingles instead of asphalt panels, homeowners can essentially "discount" the roofing price from their solar installation. The same "discount" could also be applied to skylights, railings, skylights, and other places where manufacturers could design BIPV systems.
Another added economic benefit with some BIPV systems is that they could potentially be much more durable than the building systems/elements they replace. For example, most asphalt shingle roofs have an average lifespan of 15 years. Conversely, most solar shingles will last 25-30 years with only a small drop in efficiency towards the end of that lifespan. The total economic savings associated with a BIPV roof, then, should take into consideration the cost of two roof installations. You could apply the same principle to solar facades and other BIPV systems.
Several different companies are developing building-integrated photovoltaic products and systems. Tesla was the pioneer of solar shingles but for other types of BIPV products and systems, consider the following brands:
As it stands, BIPV systems continue to be slightly more expensive than traditional solar panels. They are also less efficient in terms of converting solar radiation into usable energy for your home. However, as innovation in the world of BIPV continues to advance, homeowners should expect to see cost-effective and efficient renewable energy solutions that can integrate directly into the building components of their homes.
Tobias runs an agroecology farm and a natural building collective in the mountains of El Salvador. He specializes in earthen construction methods and uses permaculture design methods to integrate structures into the sustainability of the landscape.