The Solar Roof

By Brian Murphy

Gamechanger alert:  Tesla just stomped on the accelerator of solar technology for buildings.

Last Friday Tesla CEO Elon Musk announced the company’s new Solar Roof and Powerwall 2 electricity storage system.  The company significantly advanced electric powered automobiles before focusing its efforts on that technology’s rather important weakness: electric power storage. Tesla’s beautiful and impressive cars were perhaps most limited by battery life, a trait shared with solar technology for buildings.  Harvesting energy from the sun to power buildings has become pretty easy but it’s still a challenge to store it for use in the absence of sunlight.  The Powerwall 2 is making strides in that regard.

What’s really big about Tesla’s recent news, however, is that there is finally a major brand name with strong consumer identity that is acting on climate change in the building industry.  In a span of less than 15 years Tesla built itself into a powerhouse brand with everyday recognition internationally, which is something that hardly exists in the building science and materials arena.  The company achieved its status with its uber-sexy electric cars and an association with the stylish, social-elite set.  For them to delve into something as unsexy as roofing technology for buildings speaks volumes to the importance of tackling climate change mitigation on the buildings front.  Construction, operation and maintenance of buildings are responsible for about half the energy consumption as well as nearly half of all carbon emissions in the United States (U.S. Energy Information Administration).  We would gain more ground in slowing climate change by being more careful about what we’re doing with buildings than with automobiles.

It’s important to note that Tesla’s Solar Roof technology conceives of photovoltaic systems as a building material integrated into the building’s construction – tiles are applied to the roof like shingles – rather than distinctly autonomous equipment attached to the building like conventional solar panels.  They can be attached to a low ground-mounted structure just the same.

Also important to note is that when introducing the new product in Universal City, CA Musk identified aesthetics as being among the goals with the Solar Roof.  Though sometimes obtrusive and clunky, a solar array on a building can be perceived as an ideological statement as much as a responsible utility.  Other times the visual impact of the equipment turns out to be a non-starter for its use, especially in historic districts or homeowners associations.

It doesn’t necessarily take a power brand with critical market attention to come up with these innovative ideas – building integrated photovoltaics (BIPV) have been under development for many years to transform regular windows, cladding materials, and paint into solar collectors – but it sure helps with education and consumer awareness when companies like Tesla flash them in front of us. 

Of course the new Solar Roof system provokes some questions about construction methodology and how it integrates with conventional roof assemblies as well as concerns about snowy climates and obstructed roof surface.  These and many other questions will need to be addressed in the application of the technology.  For us, the most interesting point is that Tesla has made serious strides in bringing building science and renewable energy technology closer together.  We look forward to its development and application.