As an MIT alum interested in clean energy, I subscribe to the free semiannual magazine Energy Futures.
The purpose of the magazine is to tout MIT advances in energy technology, but since MIT (with the MIT Energy Initiative) is one of the world's cutting-edge energy research labs, I find that it is often a provocative look into a possible future that may or may not* come to fruition. (*The technology may not work, it may not scale, it may not be cost effective, something better may come out, etc. — such are the risks of technology entrepreneurship).
In the spring issue, one article describes the work of Prof. Vladimir Bulović, recent PhD grad Miles Barr and ex-postdoc Richard Lunt to create transparent solar cells. The cells absorb energy in the UV and near-infrared, but only about 30% of the visible light. This would allow the PV cells to become just another layer on a building’s windows, and could also use the window class to protect the (currently fragile) layers from the elements.
Right now, the efficiency is only 2%, but are hoping to get the efficiency up to 10-12%.
As with any BIPV (Building Integrated Photovoltaic), integrating the PV into windows would eliminate most of the installation cost; it would also mean that the PV is not an obstacle in use of the existing roof, interfere with drainage, need to cope with snow accumulation, etc.
The big win seems to be for large commercial buildings. The article claims that a 5% efficient PV cell could generate 25% of a building’s electricity. Absorbing near IR would reduce cooling in the summer (but increase heating in the window). With such a cost-benefit, the builder of a new commercial building would invest in such efficiencies (even ignoring the LEED bragging rights) while a consumer might worry about increasing the price of a house $20-50k (and would also tend to have more shading problems). If every new skyscraper had such BIPV, it would both generate a lot of energy and also be a big market.
To exploit the opportunity, the three men formed a company called Ubiquitous Energy, where Barr is president and CTO, and the other two are on the scientific advisory board. They have a $1m in seed funding and $375k in SBIR funding so far.
Like any tech startup, it’s a gamble — but this seems one with a big payout if they can solve all the challenges.