Roof Tiles in Solar’s Future
Paul Kando
According to New York solar company Suntegra, three out of four homeowners would prefer a building-integrated solar system. And solar roof tiles and solar shingles have been evolving for many years, with a number of companies working on PV as a roofing material rather than an add-on module.
photo credit: Telsa
This month, electric car and battery maker Tesla has begun taking orders for their Tesla solar glass roof, with installations to begin in June on the west coast, starting in California. It is unclear when the new roof product will be available nationwide. In addition to its new solar roof, Tesla is also introducing a conventional solar panel product and has launched an online calculator that provides cost estimates.
In contrast to traditional rooftop solar installations, which involve attaching PV modules to a building in a separate operation, building-integrated Photovoltaics (BIPV) incorporates PV in building materials, Integrating solar installation with construction, rather than adding it as a post-construction task, can result in significant savings by reducing labor and installation costs and eliminating the need for separate mounting equipment. With BIPV, solar, in effect becomes a building material and solar installers of the future may become more like roofers than solar installers.
However, significant challenges remain. These include the complexity of reliably wiring many small PV units out in the field, instead of assembling panels in a factory. Also, the hotter PV cells become, the lower their efficiency. Rooftop solar panels are mounted so that there is cooling air circulating behind them. Roof tiles get as hot as the rest of the roof.
In testing, the new Tesla roof withstood the pressure of multiple weights, including the weight of a moving person, better than conventional roof tiles. It’s made of quartz
explained Elon Musk, Tesla’s CEO. It has a quasi-infinite lifetime
and an infinite warranty
.