China has doubled its installed wind power capacity every year for the past five, and is on pace this year to supplant the United States as the world's largest market for new installations. But researchers from Harvard University and Beijing's Tsinghua University suggest that the Chinese wind power industry has hardly begun to tap its potential. According to their meteorological and financial modeling, reported in the journal Science last week, there is enough strong wind in China to profitably satisfy all of the country's electricity demand until at least 2030.

Harvard-Tsinghua project leader Michael McElroy and colleagues quantified China's wind energy potential by first modeling the availability of wind. To do this, they chopped the Chinese map into parcels 3,335 square kilometers each and used five years of recent meteorological data to generate a wind profile for each parcel. Next, they added industry-standard 1.5-megawatt wind turbines across each parcel (excluding unfriendly terrain such as steep hills, forests, and urban areas) in the model and estimated each parcel's energy output. Finally, they calculated the cost of the energy that could be produced as a function of the cost of installing the turbines.

The modeling reveals extensive regions, concentrated in northern and western China, where much energy can be generated at costs similar to the government-set energy rates earned by established wind farms, which range from 0.38 to 0.55 Chinese yuan (6 cents to 8 cents) per kilowatt-hour (kwh). For example, the model predicts that wind-farm operators could profitably generate 6.96 trillion kwh of wind energy -- more than double China's annual power consumption of 3.4 trillion kwh and comparable to the projected total demand by 2030 -- at a contract price of 0.516 Chinese yuan (7.5 cents) per kwh.

In other words, wind offers a carbon-neutral source of energy to meet China's power needs for the next two decades. Meeting incremental demand with coal-fired generation, in contrast, would generate 3.5 billion tons per year of carbon dioxide emissions (more greenhouse gas than the European Union expects to release by 2030).

McElroy, a Harvard professor of environmental studies, insists that such ambitious visions are realistic and worth seriously considering. For one thing, 0.516 Chinese yuan is at the low end of the tariffs for future wind farms that China's National People's Congress approved last month. For another, China's wind industry is already outstripping targets "year after year." China will reach its 2020 target for wind power next year, a decade early, as wind power capacity crests over 30,000 MW, according to the Brussels-based Global Wind Energy Council. By 2020, China is likely to have installed 135,000 MW of wind power capacity, according to analysis by consultancy Emerging Energy Research, based in Cambridge, MA.

However, McElroy acknowledges that China's grids would need to be smarter and stronger to accommodate the variability of wind energy. In fact, the Global Wind Energy Council says China's underdeveloped transmission system is already an impediment, delaying the start of energy production from new wind farms. And the group says the problem is becoming more acute as China's wind developments shift to the wind-rich yet remote regions in the north and west, where the grid is weaker than average and power must travel farther to reach consumers. In China's northern autonomous region of Inner Mongolia, grid limits are constraining proposed wind projects, according to Sebastian Meyer, director of research for the Beijing-based consultancy firm Azure International.