ONE OF THE state’s “Filthy Five’’ coal-burning power plants is trying to turn itself into a Cinderella of clean-burning electricity generation. Since the makeover includes a first-in-the-nation commercial use of a certain technology to reduce dirty emissions, the state should give it a closer environmental review.
In 2003, pressure for a clean-up of NRG Energy’s heavily polluting Somerset plant led the New Jersey-based company to promise to close it down or switch to a cleaner fuel - presumably natural gas - by 2010. After that, NRG took a second look at the plant, which supplies enough power for about 120,000 households, and decided it could get rid of many pollutants by first gasifying the coal and replacing 35 percent of it with wood biomass. The state in 2008 unwisely approved this approach without requiring a full environmental study. Recently, NRG said it wanted the option of replacing coal entirely with biomass.
The flaw in NRG’s plan for gasification of the coal is that, while the process emits much less sulfur dioxide, nitrogen oxide, soot, and mercury than conventional combustion, it still produces carbon dioxide, which NRG has no way of storing. Some states have underground geological formations that could contain the gas, but not Massachusetts. Nor is there any realistic plan for pipelining the gas to anyplace that has suitable formations. This state cannot be a leader in curbing greenhouse gases if it gives a green light to further years of carbon emissions.
Under its current plan, NRG could still be using up to 65 percent coal. Meanwhile, if the company were to avail itself of the option to switch entirely to biomass fuels, different environmental concerns would have to be addressed. NRG has floated the idea of using construction and demolition debris as fuel. Some of the wood could contain either lead paint or the creosote and arsenic that are used in pressure-treated lumber. NRG says none of these materials would be released into the atmosphere, but the state should take a close look at whatever evidence the firm has backing this up.
The plant NRG is proposing will be the first of its kind in the United States. That fact alone should earn it the close scrutiny that the state has so far failed to provide.