Cleaner, cheaper, but gas still not answer on energy

NEW GENERATION? Brayton Point is the largest fossil-fuel power plant in New England. A transition at the site by owner Dominion Generation to natural gas seems unlikely. / COURTESY DOMINION GENERATION
NEW GENERATION? Brayton Point is the largest fossil-fuel power plant in New England. A transition at the site by owner Dominion Generation to natural gas seems unlikely. / COURTESY DOMINION GENERATION

Manchester Street power station in Providence and Brayton Point power station in Somerset are owned by the same company and separated by just 15 miles of Interstate 195.
But the two plants sit at opposite ends of one of the largest shifts in how the United States makes electricity in a century.
The majority of the power produced at Brayton Point comes from coal, the dominant electricity source in the United States since the 1800s, while all three of Manchester Street’s generators run on natural gas, which in 1950 accounted for less than 20 percent of U.S. power generation.
Thanks to a rapid expansion of domestic natural gas production from shale rock formations, the price of natural gas has plunged in recent years. With that drop, power companies have ramped up generation from natural gas and throttled back on coal usage.
According to a July report from the U.S. Energy Information Association, coal’s share of national fossil-fuel energy generation (that is, not including power created by nuclear or renewable sources), which stood at 80 percent in the late 1980s, is now descending toward 50 percent, while natural gas is closing in on the same market share from the opposite direction.
In New England, coal has traditionally played a smaller part in electricity generation than the rest of the country, while natural gas and petroleum had out-sized roles.
According to ISO New England Inc., which operates the regional electrical grid, 51 percent of the electricity generated in New England is fueled by natural gas and that share is expected to rise to 55 percent when new facilities in development come online.
In Rhode Island, natural gas accounts for virtually all of the power made within state lines, 99 percent, while there is no significant coal production, according to ISO figures.
But while New England has certainly benefitted from lower utility bills as a result of the decline in natural gas prices, the now overwhelming reliance on a single fossil fuel has left some concerned that the region could be vulnerable to supply disruptions.
“Natural gas is powering the region and, as a result, the price of wholesale electricity now follows the price of natural gas here … as a result, many utilities across New England have announced rate cuts for their electricity customers,” said ISO New England President and CEO Gordon van Welie in a recent editorial published in Commonwealth Magazine. “It’s evident that generating electricity with natural gas has its benefits, but becoming heavily reliant on just one fuel poses challenges to the long-term stability of the power system.” In addition to use for generating electricity, natural gas is also becoming increasingly popular as an energy source to heat homes, which has the potential to create conflicts during extremely cold winters like 2011, when demand for electricity and heat spiked.
Home heat purchases of natural gas are established by long-term contracts, while power plants typically buy fuel as needed, an arrangement that has the potential to leave the electricity generators short in times of high demand.
As the difference between the cost of operating coal-fired power plants and natural-gas-fired plants has increased, power companies have converted some nongas plants to gas or shuttered them.
This has intensified calls for new investment in renewable energy, but it also creates complicated questions about what to do with existing coal and oil plants. Power generated at coal- and oil-fired plants produce more greenhouse gasses and more expensive than natural gas, but is less expensive (at the moment) than renewable sources. But they still represent an easily accessible fall-back power source.
And while natural gas prices are expected to fall in the next few years while new shale formations in the eastern United States are exploited, when new production plateaus, the increased demand for gas could send prices back up again
With 1.5 gigawatts of generating capacity, Brayton Point is the largest fossil fuel power plant in New England, and this year owner Dominion Generation completed a $570 million federally mandated project that will reduce the amount of cooling water released into Mount Hope Bay.
One of the four generators runs on natural gas and in 2007 Great Point Energy installed a coal-to-gas conversion test site at the plant, although the Cambridge, Mass., company has since moved to China.
Considering the size of the investment Dominion has made in Brayton Point, which it bought in 2005 along with Manchester Street, the likelihood that the company would close or convert the coal-fired generators seems remote.
But that’s just what is happening with another Dominion plant, the Salem Harbor power station on the Massachusetts North Shore, which is being sold to a company that plans to tear it down and replace it with a natural gas plant. In March Dominion shut down a coal-fired plant in State Line, Ind., citing the cost of upgrading it to comply with environmental regulations. Dominion declined to provide specifics on its New England generation strategy or the output of individual plants, but spokesman Dan Genest acknowledged that as natural gas has become less expensive, the company has used it more and more.
“Falling national gas prices have increased how much we are using our natural gas power stations and decreased how much we are using coal-fired stations,” Genest said. “Ultimately, it is the market that drives which stations we run and don’t run.”
While nearly all of the electricity generated in Rhode Island is fueled by natural gas, the state still uses energy made by Brayton Point and other nongas plants elsewhere.
According to state filings, the share of energy made by coal and distributed to Rhode Island by utility National Grid declined from 11.2 percent in 2007 to 7.4 percent in 2011. During the same period, the share of power from natural gas rose from 30.9 percent to 38.8 percent.
For environmentalists, the rise of natural gas has been seen as mostly positive to the extent that coal has long held the tag as the dirtiest energy source due to its high greenhouse gas emissions and pollution caused by mining.
Brayton Point is by far the largest carbon dioxide producer among power stations in New England, emitting 5.9 million metric tons of greenhouse gasses in 2010, according to figures released this summer by the U.S. Environmental Protection Agency. By comparison, Manchester Street, the largest greenhouse producer in Rhode Island, emitted 873,000 metric tons.
But environmentalists point out that burning natural gas still produces emissions that lead to global warming and the extraction of natural gas, through methods such as “fracking,” release methane and have their own environmental problems.
“We have always said natural gas is an appropriate transition fuel from the dirtiest source of energy, coal, to renewable energies,” said Tricia Jedele, vice president and Rhode Island director of Conservation Law Foundation. “But ideally we want to get to a place where we are relying more on efficiency and renewable energy. Anytime you can take the most polluting source of energy offline, that is a good thing, but natural gas is not the answer long term.” •

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