Monday, September 28, 2009

The Other Side of Wind Power

China's been lauded a lot for its efforts in going green. Indeed, China does seem to be taking climate change seriously. But at the same time, China, and the rest of the world, have a long ways to go in terms of weening itself off of carbon-emitting energy sources.

From The Wall St. Journal:

Photo from CS Monitor

SHANGHAI—China's ambition to create "green cities" powered by huge wind farms comes with a dirty little secret: Dozens of new coal-fired power plants need to be installed as well.

Part of the reason is that wind power depends on, well, the wind. To safeguard against blackouts when conditions are too calm, officials have turned to coal-fired power as a backup.

China wants renewable energy like wind to meet 15% of its energy needs by 2020, double its share in 2005, as it seeks to rein in emissions that have made its cities among the smoggiest on Earth. But experts say the country's transmission network currently can't absorb the rate of growth in renewable-energy output. Last year, as much as 30% of wind-power capacity wasn't connected to the grid. As a result, more coal is being burned in existing plants, and new thermal capacity is being built to cover this shortfall in renewable energy.

In addition, officials want enough new coal-fired capacity in reserve so that they can meet demand whenever the wind doesn't blow. This is important because wind is less reliable as an energy source than coal, which fuels two-thirds of China's electricity output. Wind energy ultimately depends on wind strength and direction, unlike coal, which can be stockpiled at generators in advance.

Further complicating matters is poor connectivity between regional transmission networks, which makes it hard for China to move surplus power in one part of the country to cover shortfalls elsewhere.

China may not be alone in having to ramp up thermal power capacity as it develops wind farms. Any country with a combination of rapidly growing energy demand, an old and inflexible grid, an existing reliance on coal for power, and ambitious renewable energy-expansion plans will likely have a similar dilemma. What marks China out as different is the amount of new coal-fired capacity that needs to be added.

...

"China will need to add a substantial amount of coal-fired power capacity by 2020 in line with its expanding economy, and the idea is to bring some of the capacity earlier than necessary in order to facilitate the wind-power transmission," said Shi Pengfei, vice president of the Chinese Wind Power Association.

Read On
It's seeming more and more like significant steps towards actually getting away from our CO2-powered lives are not that close to becoming a reality.

That's unfortunate.

2 comments:

info said...

My students, who are working on their electronics science fair projects, thought that this story about using coal as a back up energy source is an environmental cop-out. There are many different alternative energy sources that China could use as a back up energy source that would be less polluting than burning coal. Does any one know if China has looked into coal alternatives?

Mark said...

China's inability to really ween itself off of coal surely has a lot to do with its gigantic coal resources.

China is looking into coal alternatives and is investing massively in them. But it's obvious that despite such commitments, coal is going to be vital to China's growth for at least another generation.

In addition to the human-created coal issues, naturally occurring underground coal fires are another huge burden that aren't going away anytime soon.