A commercial coal-fired power plant in Estevan, Saskatchewan is the first of its kind to implement a carbon capture and storage (CCS) system. In other words, it’s burning the dirtiest fuel in the world without any of the greenhouse gas emissions.
How is this possible? The answer is neither cheap nor simple.
Coal is indeed the dirtiest fossil fuel on the market, but its ubiquity and affordability make it an enticing fuel source, especially for developing nations. Consequently, the burning of coal is a major cause of global warming, as carbon and other greenhouse gases are emitted into the atmosphere where they trap solar radiation and gradually increase the planet’s temperature. Clean, renewable energies are seen as the answer to stopping an average temperature increase of two degrees Celsius (an internationally agreed-upon threshold for limiting the worst climate impacts), but if CCS became mainstream, coal plants could continue to operate without affecting the environment.
Canada’s Boundary Dam power plant, owned by SaskPower, works like so: After burning its coal, the plant pumps its emissions into a 52-meter-high column of liquid. Filled with chemicals called amines, they suck up 90 percent of the carbon dioxide. The remaining CO2 is cooled and then compressed into a supercritical liquid, a portion of which is injected into a saline aquifer located 3.4 kilometers underground. The rest of it is transported 65 km away to an oilfield where it is used to boost the output of maturing wells.
This whole system cost $1 billion to put together. On top of that, the CCS technology requires about 20 percent of the plant’s 160 megawatts. Some of that cost is offset by selling compressed CO2 to the nearby Cenovus oil field, and SaskPower admitted to MIT that it could build a new system for about $200 million cheaper after learning from the experience of building this one.
If more power companies adopt CCS rather than renewables, the Intergovernmental Panel on Climate Change estimates that CCS systems could become one-third cheaper than the Boundary Dam model.
Currently there are only two other CCS power plant projects under construction in the world, both located in the U.S.
When fully operational, the Petra Nova Project in Thompsons, Texas will be the biggest CCS facility in the world (granted, it’s not much of a benchmark at this stage). A joint venture among the U.S. Department of Energy, JX Nippon and NRG Energy, Inc., it will capture an annual 1.4 million metric tons of carbon dioxide from the adjoining W.A. Parish Generation Station and store it in a depleted oil field nearby.