Solar Eclipse


Wind faces a nano-scale threat.

Wind faces a nano-scale threat.

Fortnightly Magazine - May 2010

For decades now, wind turbines have been generating electricity more cheaply than most other (non-hydro) renewable energy technologies. In particular, wind has maintained a comfortable lead over solar energy in the price-per-kWh race.

For instance, a leaked “confidential” report 1 prepared for the City of Los Angeles last year estimated that rooftop PV systems being contemplated by the Department of Water & Power would cost about $7,000 per kilowatt to install, with a 20 percent capacity factor. The report said these capital-cost figures were triple those for equivalent wind capacity (which on average generates with about a 30 percent capacity factor), and 1.5 times the price of solar thermal power.

Given wind’s clear economic advantage, the industry has focused most of its renewable-related attention on wind power. Transmission development efforts and policy processes have concentrated on bringing remote wind resources into load centers, and system operators have worked to accommodate wind’s variable and non-dispatchable nature (see “ Beyond Intermittency ”). In short, with few exceptions, wind stands at the top of the renewable pecking order.

That’s destined to change.

Although wind still maintains a lead in the cost race, solar has begun making its move, and likely will catch up with wind and pass it in the foreseeable future. The reason is a fundamental difference in the two types of technology, and their different opportunities for improvement.

Wind R&D mostly focuses on large-scale problems in materials, design and management—including wind forecasting. By contrast, solar research—especially PV—focuses mostly on very small-scale materials and designs. And on that very small scale—the nano scale—technology is advancing at a pace that even today’s cloud-scraping wind turbines can’t possibly match.

PV and Moore’s Law
EES North America

Investors and technology developers increasingly view wind energy as a mature technology, whose costs have reached a practical floor. Of course, that’s not to say wind won’t become more economical in the future. R&D continues advancing the efficiency and performance of equipment and facilities. Forecasting in particular is raising the overall value of wind energy on regional power networks.

Such progress is driving down wind’s effective price-per-kWh, but wind’s cost-per-kWh probably won’t improve at anything resembling an exponential or even steady linear pace. Costs will fall at an incremental pace, with that progress slowing down over time. This is no secret, but it will become a serious competitive disadvantage for wind power as PV technology advances.

According to Ray Kurzweil, futurist and author of The Singularity is Near , the historic rate of advancement in PV technology matches that of information technologies— i.e., it proceeds at an exponential rate, in keeping with the now-famous Moore’s Law. But where Moore’s Law predicts a doubling in IT processing power every 18 months, Kurzweil says the data show PV’s cost-per-kWh drops 50 percent roughly every two years (see Figure 1) . This logarithmic advancement rate is connected to PV’s dependence on nanotechnology R&D.

“Nanotechnology is inherently an information technology,” Kurzweil told an audience of