MIT produces glass-like solar photovoltaic cells

A potentially major breakthrough for the future of solar photovoltaic power has been achieved at the Massachusetts Institute of Technology (MIT): organic solar cells that are transparent for visible light, but collect infrared radiation for electrical power production. This promising technology could offer savings on construction costs as well as operational costs (i.e. less need for air conditioning during hot summers) for buildings.

In a previous Solar Choice blog entry, we discussed the future of BIPV, or building-integrated photovoltaics: solar photovoltaic cells that can be used in the place of building materials, simplifying solar system installation and eliminating the need for additional components such as solar panel array mounting brackets. Some of the multifunction technologies mentioned were photovoltaic awnings and windows, which integrate solar cells of different compositions into glass, blocking light and creating shade from the sun while at the same time capturing sunlight for power generation. The new technology under development at MIT is another major step toward seamlessly working PV technologies into everyday building materials; another tool in the toolbox of sustainable building design.

An MIT News article about the technology references the academic journal article co-written by Richard Lunt and Vladimir Bulović in which the research results were published. It points out that at the moment half to two-thirds of the costs associated with thin-film solar power are attributable to the installation itself, and up to half are due to the glass and structural structural of thin-film PV modules.

The amorphous PV technology has achieved a new high level of efficiency for organic, transparent cells–a level that may become comparable to conventional silicon cells–but currently stands at 1.7%. At the moment, for similar technologies, this number stands at less than 1%.  Bulović admits that it will be a challenge to reach 12%, the conversion efficiency that is commonly achieved by modern mono- and poly-crystalline silicon panels. Getting to that point will require excitonic engineering to optimise the composition and configuration of the photovoltaic materials, Bulović says. He also speculates that it could be available as a practical, manufacturable building component within a decade, although as part of a ‘family of solutions to the world’s energy needs.

Written by James Martin

Solar Choice Analyst

Sources and Links:

Applied Physics Letters (academic journal), “Transparent, near-infrared organic photovoltaic solar cells for window and energy-scavenging applications”

MIT News, “Turning windows into power plants” (Photograph of Richard Lunt by Geoffrey Supran, from this article)

Previous Solar Choice blog entries: BIPV : Thin-film flexible solar cells : What type of solar cells are right for you? : PV awnings, asbestos concerns

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