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Solar industry : "We are within 5-15 years of full competitiveness"
8 Aug, 2009 10:11 pm
Last week, solar-industry experts at a symposium of the National Academies in Washington DC on the topic of scaling up the solar industry complained that the emphasis on finding new technologies was misplaced. Prof. Ken Zweibel, director of Solar Institute at the George Washington University, answers Scitizen's questions.
You declared in Washington DC : "To some degree, we're fighting the last war". Can you elaborate on this?
The meeting was about channeling public funding into a very rigid technical roadmap based on a semiconductor industry model. That was regarded by most experienced attendees as unnecessary and likely destructive because there is a plethora of existing solar technologies that differ radically from each other. Similarly, the idea of focusing a majority of federal funding on “futuristic” photovoltaic (PV) technologies was also regarded as unnecessary and even counterproductive (distracting from, and reducing the talent accessible for existing options).
What are futuristic solar technologies?
Futuristic technologies are pre-commercial ones not based on crystalline silicon, or the thin films that have been commercialized – cadmium telluride (CdTe), amorphous silicon, copper indium diselenide alloys; or on gallium arsenide (GaAs) or its alloys for multijunctions used in solar concentrators. Dye cells are between futuristic and commercial since they have attracted some investment. Examples of futuristic technologies are plastic solar cells and those that depend on novel nano-style designs.
Futuristic solar options have been repeatedly examined and dropped over the last three decades; others that have promise will take decades to fully develop; and many have not actually been evaluated for their potential to even contribute more than has been achieved.
Is solar competitive right now?
No, but it has come down in cost from an order of magnitude more expense and is now within range of being competitive. It has a track record of continuous improvement that suggests we are within 5-15 years of full competitiveness. Meanwhile, technical roadmaps for reaching full competitiveness exist for multiple existing PV technologies. Not only are breakthroughs not needed, but the futuristic options are less promising than the existing ones (and haven’t been evaluated in comparison to them).
What should the solar industry focus on next?
The solar industry is focused on (1) gaining access to more subsidized markets like those in Europe and to a lesser degree in the US; (2) aggressively reducing cost as they have recently (from $5/W in 2008, to $4/W in 2009, and possibly $3/W in 2010 for large systems) so that subsidies can be reduced and eventually dropped; (3) focusing R&D and technological improvement on key challenges within the scope of their existing technologies; and (4) gaining support from knowledge brokers (like this organization) who portray the status of technologies (since the true status of PV is little understood). Those who fund solar, e.g., the Federal government, should also do these things. One further priority: develop a technical roadmap of key approaches and issues for expanding solar deployment to high levels, e.g., to where grid stability becomes an issue; to where long distance transmission from high-sunlight regions will be needed; and to where electric storage is likely to be needed.
Interview by Clementine Fullias
Ken Zweibel subsequently cofounded and became President of a thin film CdTe PV start-up, PrimeStar Solar. He became the founding Director of The George Washington University Solar Institute at its formation in 2008.