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Behind the Design: How Solar Roof Tiles Really Work

Tesla’s solar tiles are the latest in roofing technology. Why are these sun-soaking mini panels such a big deal?

Sydney Franklin Sydney Franklin

Each week, Architizer is highlighting a different building product and how to specify it. This week’s topic is roof tiles and shingles. If you’re looking for the perfect roof tile or shingle for your next project, search for it Architizer’s new network marketplace for building-products. Click here to join our waitlist. It’s free for architects.

News has radiated around the roofing industry in recent weeks thanks to Tesla’s introduction of its new solar roof shingles, which are coming into pilot production right now. Elon Musk’s plan to provide homeowners with a new-and-improved version of resilient, miniature solar panels is a monumental step for proponents of sustainable housing — and overall for the future of green building in the United States. Musk’s goal is to sell the preeminent product as an ultra-attractive roof replacement method. With over five million roofs annually swapped out in this country alone, solar cell roof tiles have the potential to make a big impact.

Image via Tesla

But what exactly are the benefits of this sunshiny science, and how is it different than the conventional solar panels that people have been installing on top of their existing roofs for the last few decades?

To answer that question, we must go back to 2011. The Dow Chemical Company was the first manufacturer to venture into the solar shingle business, launching the game-changing PowerHouse Solar Shingle, which was made to look like a normal asphalt shingle. Essentially a small-scale version of their popular solar panels, the solar shingle was infused with copper indium gallium (di)selenide (CIGS), allowing the thin-film solar cells to reach a conversion efficiency of 19.9 percent — just 0.4 away from the maximum output of the standard solar panel.

Image via 150 Points

Not only was the solar shingle nearly as sun-soaking as its solar panel big brother, it was easy to install. Solar panels, which are traditionally large-frame products with silicone cells, must be drilled onto a roof through existing shingles and sealed with caulk to ensure watertightness. Solar shingles, on the other hand, require zero drilling. They’ve quickly became known as not an extension of the roof, but the roof itself.

Talk about getting off the grid without being obvious. These types of products fall under the category of building-integrated photovoltaics (BIPVs): solar modules that are incorporated as construction materials. BIPV is already a hot topic in green building, as we’re seeing parts of architectural envelopes being commonly replaced with photovoltaics. BIPVs are aesthetically pleasing and reduce labor and installation costs.

A typical example of a BIPV roofing system; via Haidu

We already know how solar power systems work and have seen their benefits, but we don’t yet know the long-term success of those systems becoming embedded within construction technology. After all, direct electricity generation isn’t something only our bodies can do, but something buildings can do, as well. And with solar shingles serving as the future staple roofing product, there’s no end to the savings — both physically and fiscally.

But selling building-integrated photovoltaics has not proven an easy feat. That’s why companies like Tesla, SunTegra and CertainTeed are vying to rebrand the solar shingle. SunTegra’s shingles are offered as a two-in-one roof and solar solution. Its shingles and tiles are long, lean and directly attach to a roof while integrating with composition shingles and flat concrete tiles, respectively. CertainTeed offers the same approach with Apollo II, using high-efficiency, monocrystalline, silicon solar cells to generate clean power.

SunTegra’s solar shingle installation process ensures a seamless look next to existing shingles; via TreeHugger

Via SunTegra

Tesla’s solar tiles, however, are next-level. After Dow closed production on its solar shingles last year, a huge gap was left open for an innovative company like Tesla — driverless cars, move aside! — to disrupt the solar power industry even further with a forward-thinking product that looks and acts like ordinary shingles. SunTegra and CertainTeed offer homeowners perfectly functioning BIPV systems but without the distinct appearance of a real shingle or tile.

Last fall, Tesla acquired SolarCity, a developer and solar-services provider, to engineer a sleeker and stronger shingle that’s more than three times as strong as standard roofing tiles.

Tesla’s tile make-up; via Tesla

Tesla’s tile (left) withstands a huge hailstone, while conventional tiles shatter; videos via Tesla.

The tempered glass tile is said to be able to withstand the impact of a hailstone traveling 100 miles per hour. What’s more, Tesla’s elegant solar tiles are set to come in four stunning forms come 2018: textured, smooth, tuscan and slate. These tiles, once aligned together encompassing an entire roof, will perfectly mimic the look of normal shingles and tiles.

Images via Tesla

Despite its technological significance, this is a conversation about aesthetics as much as functionality. But what is a roof other than the physical thing that encloses and protects a building? It is part of its cladding. It is part of the architecture’s overall design. It has the potential to be beautiful. As all good architects know, such small-scale details can hold extraordinary power.

Hero images via Tesla

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