With the high – real or perceived – cost of renewable energy, many companies in China are looking to "clean coal" technologies such as carbon capture and storage (CCS) and integrated gasification combined cycle (IGCC) as ways to reduce carbon dioxide emissions.
Coal currently provides 80% of China’s electricity, and much of it is mined domestically. Using CCS technology would allow that energy independence to continue while providing a relatively clean source of power that doesn’t suffer from many of the grid connection problems that plague renewables.
Huaneng, one of China’s Big Five power producers, has two demonstration plants up and running, and is working with US-based Duke Energy on the technology.
But true independence may be a while off – with China’s current capabilities, the technology isn’t yet commercially viable. "The main issue is storage," said John Romankiewicz, a carbon markets analyst with New Energy Finance. "It’s called carbon capture and storage. Capture is on the way to being solved, but storage has hardly broken through."
Once extracted from coal, carbon dioxide needs to be stored in saline aquifers, depleted oil wells or natural gas deposits. A recent US study said most coal-fired power plants in China are located within 160 kilometers of a suitable storage site, which could reduce the cost of using CCS in China. However, carbon experts warn there is no guarantee that storage facilities would prevent carbon dioxide from leaking into the environment.
There are other costs as well. Demonstration plants can process a ton of coal for US$100-150. That could drop to US$30-50 once the process is commercialized, but this is still almost 80% more expensive per kilowatt than traditional coal, said He Gang, a research associate at the Freeman Spogli Institute for International Studies’ Program on Energy and Sustainable Development at Stanford University.
Clean coal also requires 20-30% more coal to maintain the same level of energy as conventional coal power. That would stretch China’s already strained coal supply chain, and presents a cost problem for the power companies.
"[If] the power companies can’t pass the cost of coal to the end user, how can they pass the CCS cost?" said He.
Despite all these challenges, David Mohler, chief technology of Duke Energy, says that clean coal can be viable in the long term.
"Some of the things I have seen [in China] lead me to believe it is beginning to sound like it could be feasible on a large scale basis," he said.