Breakthrough

MIT's "major breakthrough" has certainly garnered the attention of the media this week and last, but is it really the transformational discovery it claims to be? Peter Teague, environment policy expert, Michael Shellenberger, President of the Breakthrough Institute, Greg Nemet, University of Wisconsin energy expert, and Frank Laird, professor of technology and public policy at the University of Denver, get to the bottom of MIT's announcement.

Peter Teague: MIT has announced a "major discovery" that could transform solar power from a marginal, boutique alternative into a mainstream energy source. MIT researchers have overcome a major barrier to large-scale solar power: storing energy for use when the sun doesn't shine.

What do you think - is this really a breakthrough?

Michael Shellenberger: I'm not sure what to make of it. Joe Romm critiques the hype surrounding the innovation.

I am more skeptical of solar PV than I was a year ago for a few reasons. The first is that David Keith, a very good scientist in Canada, did in-depth interview with non-interested experts, most of whom didn't see PV getting much greater efficiencies anytime soon without major government investment in development and deployment. The obvious reasons inventors hype their innovations is: a) they're genuinely excited and b) to raise VC money. Hence the need for non-interested experts.

The second reason is that I am more skeptical now of decentralized energy generation. I don't see many people wanting to make their own energy for a variety of reasons. So if PV takes off I think it will take off in big centralized farms, not on homes, and there I don't think it will be able to compete on price with concentrated solar power (CSP -- big mirrors and simple turbines) for a long time. Perhaps Greg Nemet and Frank Laird can weigh in here...

Greg Nemet: Some students at U.C. Berkeley have raised questions about the rate at which the hydrogen is produced in the MIT device.

If it's slow and there is no easy way to speed it up, then that could pose a limiting factor for the ultimate economic feasibility of the storage aspect of this technology. In any case, it's way too early to either dismiss it or to expect the most optimistic outcome.

If there is even a 5% chance that this technology eventually becomes commercially available and cost competitive with coal and gas, then it is something to be very excited about.

Frank Laird: I read Joe Romm's critique and did not follow it. I haven't read the Science article yet, but I seriously doubt that it proposes breaking the laws of thermodynamics. As far as I can tell, no one is proposing free energy or perpetual motion, and both Nocera and Science are too smart to make that sort of elementary error. It's a bizarre critique. The notion that sunlight, by generating a photosynthetic-like chemical reaction, releases energy, is hardly a radical notion.

Is this exciting news or not? Greg's right that it's too soon to tell. At this stage of developing renewable energy technologies, let a thousand flowers bloom. The bad ones will get sifted out if we have the right policies in place.

As to hydrogen: there's no reason to close that door at this time. Of course it's true that any energy conversion process loses energy. That is, in crude terms, one of the laws of thermodynamics. Therefore, the more conversion steps you have in a process of delivering energy services, the greater the loss of energy and so, in an engineering sense, a loss of efficiency. That's true too but so what? If the energy you get out is sufficiently valuable in financial terms to justify the energy loss, then go ahead and take the loss. Though I'm rarely one to say this, sometimes economic efficiency is more important that engineering efficiency. Let's just line up the alternatives and see what falls out.

Romm is correct that concentrating solar power is going to make the biggest dent in the near term. I went to a briefing today from 5 different CSP firms (at least 3 of which, by the way, were US subsidiaries of foreign firms, but that's a topic for another day). They represented diverse technologies (parabolic troughs, dishes, power towers, and fresnel concentrators feeding both thermal and PV systems) and business models and they all have completed or under-construction projects. They think in terms of 100s of MW and talk about soon having GW levels of installation. SolarOne in Nevada uses a nitrate salt storage medium to give them several hours of storage. The growth potential in the American Southwest is huge, though it is almost nil elsewhere in the United States for CSP. Interestingly, all these folks ALSO think we need more innovation so that we can have cheaper, more reliable, etc. technologies. They will start deploying what they've got, but they want lots more innovation as well. The two are not mutually exclusive.

To Michael's point on scale: certainly in the short term the large scale installations, whether solar, wind, or whatever, make the most sense. And I'm a skeptic that household solar will be more than a very small part of the market. But there is something in between, sort of intermediate scale stuff. Think of all the flat roofs in the United States; the acreage must be huge. If the owners leased them out for PV or something similar, one could have significant installed capacity with zero land use problems. For an interesting possible innovation in intermediate scale CSP, see the work going on at Raw Solar, a new startup founded by MIT students, not professors. I have no idea if they'll succeed, but they have interesting ideas about making CSP very cheap, and the technology is modular and scalable with no real economies of scale after a certain point.