The inventor of a see-through solar technology reviewed by Lloyd some years ago made news again this week with an article in Nature Energy on the "Emergence of highly transparent photovoltaics for distributed applications."
Based on a review of the current state of transparent photovoltaic technology, Lunt reports,
"We analyzed their potential and show that by harvesting only invisible light, these devices can provide a similar electricity-generation potential as rooftop solar while providing additional functionality to enhance the efficiency of buildings, automobiles and mobile electronics."
Roof-top solar and solar field arrays have made great inroads in supplying renewable energy from the sun, but these options leave a lot to desire in dense urban areas where the roof-top area per capita and unused real estate offer little hope of keeping up with demand.Lunt's team calculates that with 5-7 billion square meters of glass in the USA, the use of transparent solar cells on glass surfaces combined with traditional rooftop panels could come close to meeting U.S. electricity demands. Presumably the calculations hold even more true in the more population dense countries of the world.
Lunt reports that transparent solar cells are now recording efficiencies that top 5%, which is still only about a third of the efficiency boasted by commercial standard solar panels and a pale shadow of the current record in research solar cell efficiency of 46%.
As Lloyd often notes, architects need to take care to get energy conservation right before charging full speed into claims that transparent photovoltaics coating an inefficient building magically make poor design "green." But the ability to use innovative solar harvesting technology will certainly expand the capacity to generate the energy needed to make a break from fossil fuels and improve CO2 emissions performance.