TURNING coal into gas before burning it is an excellent way to reduce its toxic pollutants, including mercury, and capture its carbon dioxide emissions, the most important greenhouse gas. But this is beneficial only if there is a practical way to put the CO{-2} away forever - either deep underground or under the ocean. That is why state officials should require a full-bore environmental review of a plan by a power generator in Somerset to begin gasifying coal at its plant there.
The Somerset facility, which produces enough power for about 120,000 households, is under strict orders by the state to cut down, by 2010, in the sulfur dioxide, nitrogen oxide, soot, mercury, and other toxic pollutants it emits. The plant's owner, NRG Energy Incorporated, proposes to meet the requirements by first gasifying the coal before burning it. This would greatly reduce those pollutants, but it would do nothing to curb carbon dioxide unless there is an affordable way to sequester it securely.
Unfortunately, no one has done any studies whatsoever of potential sequestration sites in Massachusetts. Coal mines in Pennsylvania or locations in New York state might eventually prove suitable, but even they have not been tested thoroughly. Building and operating a pipeline system to transport CO{-2} from the Somerset plant to distant mines or other geological formations could be prohibitively costly. Unless a more feasible option arises, the plant's carbon-capturing strategy would amount to little more than catch-and-release.
The company also proposes to reduce its carbon footprint by replacing some of the coal with biomass - in the form of logging residue, urban tree-trimming waste, stumps, pallets, and demolition debris - or biodiesel from soy or palm oil. Biomass is considered carbon-neutral because the plant material gets its carbon from the atmosphere, instead of releasing it from deposits deep in the ground. But the company has made no commitments on how much if any of the coal would be replaced by biomass.
In August, the state Department of Environmental Protection issued draft approvals for NRG's plan without asking the firm to meet the full reporting requirements of the Massachusetts Environmental Policy Act. The state should call for such a review. That way, NRG would have to do an analysis of the project's impact on greenhouse gas emissions and spell out possible mitigation measures. If biomass is to be used as a way to reduce the plant's carbon emissions, the state should require both a detailed plan for where such material will come from and a commitment from NRG on how much coal will be replaced.
Simply reducing some pollutants isn't enough. The state should not be approving power-plant upgrades that would hasten the climate catastrophe of global warming.
