Wind power 'could cut China's emissions by 30%

China's energy needs are expected to double by 2030, but a study in the journal Science says the country could produce 30% less CO2 if it uses wind power to meet them
guardian.co.uk, Friday 11 September 2009 12.14 BST
China could cut its CO2 emissions by 30% in the next two decades if it uses wind power to meet its growing energy demands, a US study said today.
It is estimated China will need to increase its capacity by 800 gigawatts by 2030 to meet demand – roughly double its current capacity.
The study, in the journal Science, proposed a way for wind power to make up most of that increase and, if it did, said China's emissions of carbon dioxide could be 30% lower.
Using meteorological data to assess the potential for wind power in China – the world's largest emitter of carbon dioxide – the researchers also say wind could theoretically supply all of the country's energy, though it only laid out the figures for meeting half its needs.
"The world is struggling with the question of how do you make the switch from carbon-rich fuels to something carbon-free," lead author Michael McElroy, a professor of environmental studies at Harvard's School of Engineering and Applied Sciences, said. "The real question for the globe is: what alternatives does China have?"
Coal currently supplies 80% of China's electricity, and hundreds of coal-fired power plants are built every year to keep pace with demand, but Beijing is also investing heavily in renewable energy.
It plans to build seven large wind-power bases over the next decade, and already ranks fourth in the world in terms of installed capacity, at 12.2 gigawatts – about equal to the energy produced by two dozen average-sized coal-fired plants.
It trails only the US, Germany and Spain in installed capacity, but not all of those turbines are hooked up to the electricity grid. In fact, just 0.4% of China's electricity is supplied by wind – or around 3 gigawatts.
Justin Wu, a wind analyst at New Energy Finance, a London-based industry-research firm, said the gap between installed capacity and wind-generated power is more than just a footnote. Connecting the wind farms to national electric grids is very difficult and expensive, he said, because the on-and-off blowing stresses the grids. He said the study does not take into account that in order to overcome this difficulty, power grids would need costly upgrades.
"It's not possible to have 100% of a country's energy demand coming from wind using current technologies, because it requires quite a bit of advancement in smart grid technology to accommodate the unstable effect of wind," he said. "Without real advancements in grid technology or power storage, you will not be able to do that."
The innovation is only likely to be undertaken by power companies if they're offered big incentives to offset the costs – incentives that are so far lacking.
Still, analysts note that China has shown a commitment to renewable energy and may be able to overcome the problems; it is now the fastest-growing market for such energy. The US-based First Solar Inc said this week it had received initial approval from China to build what may become the largest solar field in the world, in Inner Mongolia.
The researchers behind the Science study proposed that the country could produce 640 gigawatts from wind farms, assuming they ran at 30% average capacity – a measure of how much output can reasonably be expected from a wind turbine. Average capacity takes into account that wind is fickle, and calculates more or less how much of the time you can expect a turbine to be working at full capacity.
Thirty percent is at the high end of estimates for most wind projects. In China, most tend to average about 23-24% capacity. At current prices, the study said the plan would require an investment of about $900bn (£539bn).
"The present analysis suggests that wind resources in China could accommodate this target. This will require, however, a commitment by the Chinese government to an aggressive low-carbon energy future," said the study, which was carried out with Tsinghua University in Beijing and supported with a grant by the US's National Science Foundation.
While the study also put forth the notion that wind could eventually meet all of China's needs, Julian L Wong, an analyst at the Washington-based thinktank Center for American Progress, cautioned against relying too heavily on it, saying wind is not a substitute for sources like coal, natural gas or nuclear power.
A shortage of wind could be devastating for industry, Wong said. While electricity from wind can be stored when too much is produced and used when winds die down, he said it is unrealistic to expect storage technology would have advanced enough in the coming decades to allow China to be entirely powered by wind.