China’s State Council has announced that it is banning the construction of new coal-fired power plants near Beijing, Shanghai and Guangdong. The goal is to cut air pollution in the country’s eastern megalopolises. The hope is that by 2017 Beijing residents will be breathing in 25% less fine particulate matter than in 2012. China’s annual coal consumption surpassed 1 billion short tons per year in 1988 and has exploded since then, to an estimated 4 billion tons this year.
By shifting new power plant construction to natural gas, nuclear and solar, China hopes to bring its reliance on coal down below 65% of total power generation, from about 70% today (the U.S. gets about 35% of its electricity from coal). That shift is underway, with dozens of nuclear plants under construction. The expectation is that China’s nuclear capacity will grow from 12.5 gigawatts now to 50 GW by 2017.
Meanwhile, the Obama Administration is seeking to mimic the Chinese playbook. The Environmental Protection Agency has reportedly drafted a proposal to block new coal power plants in the U.S. unless they are outfitted with technology to capture and sequester carbon dioxide. Such technology exists, but it is so prohibitively expensive in terms of capital costs that no investor would dream of taking the risk.
The proposed limits would be 1,100 pounds of carbon dioxide emissions per megawatt-hour for coal-fired plants and 1,000 pounds per mWh for natural gas-fired plants.
Natural gas technology would meet the proposed standards. The average “combined cycle gas turbine” emits just under 800 pounds of carbon dioxide per mWh.
But just how impractical are those emissions limits on coal? Hugh Wynne, analyst with Bernstein Research, writes in a note today that the most efficient coal-fired steam turbine generators put into service the past five years have average emissions rates of 1,900 pounds per mWh.
Trapping carbon dioxide and injecting it deep underground can be done, but according to Wynne it would nearly double the capital costs of a coal power plant to roughly $112 per mWh of capacity.
There’s one coal plant with carbon capture technology being build in the U.S. right now. Southern Company’s Kemper County plant in Mississippi will gasify pulverized coal into a mixture of carbon dioxide and synethic natural gas. The natgas it burns to power a turbine while the carbon dioxide will be injected down into an old oil field to help loosen and push up more crude oil. As the oil comes out, the carbon dioxide remains trapped in the interstices of the reservoir.
Naturally, this mode of carbon sequestration only makes economic sense when there’s a big oil field nearby.
No doubt other novel technology will emerge to help reduce the carbon emissions of coal. One idea involves pumping smokestack emissions through beds of lime water. The chemical interaction of the carbon dioxide and the lime (calcium oxide) forms calcium carbonate.
The EPA rules haven’t been finalized yet, but the draft proposals represent just the newest salvo in Washington‘s war on coal.