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Massachusetts Leading the Way in Landfill Gas-To-Energy Generation Methane Capture Systems Produce Electricity That Is Sold To The Grid
 Many of the state's municipal solid waste landfills - whether active or capped - generate significant amounts of leachate and methane. Containing leachate and preventing methane from reaching explosive levels, or escaping to the atmosphere, have long been essential components for any closure and monitoring plan at landfills.
Recently, however, a greater emphasis has been placed on installing systems that do more, specifically with the methane gas. Landfill operators and regulators have increasingly looked at Landfill Gas-To-Energy (LFGTE) as a means of capturing and converting potentially harmful methane into energy or electricity.
This innovative idea has the regulatory support of MassDEP and the state Division of Energy Resources (DOER). Currently, there are15 landfill sites across the state producing approximately 50.6 megawatts (MW) of power, with another four sites under construction and two existing sites lining up to possibly expand in the future (another 9.3 MW of power). A megawatt is enough energy to power about 1,200 New England homes.
Many of the existing LFGTE systems were installed after 1996 when MassDEP adopted guidance specifically for such systems, establishing a level playing field regarding the level of emissions these systems were expected to meet.
Most recently, (June 2007) Quarry Energy Corporation of Quincy received approval to move ahead with a LFGTE system that, once operational, is expected to produce 0.6 MW (or 600 kilowatts) of electric power to the grid.
Historically, LFGTE systems were used only in limited numbers, chiefly because of simple economics, i.e., did the cost of installing, operating and maintaining the landfill gas capture system balance against the income received from tax credits and sale of energy/electricity that would be generated?
Another issue was the concern about the odor-causing contaminants in landfill gas. But it was found that those issues could be minimized with adequate air quality controls, along with sufficient setbacks and compliance testing on actual emissions and noise levels.
Landfill Gas Systems Diversify Energy Supply
Two other key factors are also serving to bring about the development of additional LFGTE systems. Chief among these is the need to diversify the state's energy supply. Massachusetts is not alone in looking to get a larger percentage of energy from renewable fuels, and that includes biomass (agricultural and organic sources) and other new renewable fuels. Under the state's DOER regulations, landfill gas is considered eligible as a new renewable fuel.
Closely following that is the issue of global warming and the focus on reducing methane emissions. Methane is 23 times more potent a greenhouse gas than carbon dioxide. The federal Environmental Protection Agency (EPA) states that nationwide (2004) municipal solid waste landfills were the largest source of human-related methane emissions (25%).
Of course, any landfill will generate methane only until its biomass has decayed. So, the amount of energy that can be generated is relatively short-term and subject to site conditions, but so long as the methane is present, LFGTE proponents say it makes sense, as the old adage goes: when life gives you lemons, you make lemonade.
In Massachusetts, the number of LFGTE systems operating - and the amount of energy they produce - fluctuate due to site conditions. Currently, the state's largest active landfill, located in Fall River, has in place two separate systems that generate 2.1 and 5.2 MW of power respectively. Not all these systems work out: one system in Braintree and another in Amesbury were installed, but ultimately de-commissioned and currently remain off-line. Some cities, like Westfield, have systems that generate as little as 0.4 MW.
Others have proved more successful. In Chicopee, one of its landfills has a total of three systems in place, each has a capacity of 1.9 MW, while a second Chicopee landfill is permitted at 1.8 MW.
Nationwide, the EPA reported (in December 2006) approximately 425 LFGTE projects, generating approximately 10 billion kilowatt-hours of electricity per year and delivering 230 million cubic feet per day of landfill gas to direct-use applications. The EPA also estimates that approximately 560 additional landfills present attractive opportunities for project development.
Currently, Massachusetts has a number of LFGTE projects in the development or planning stage, including: Fitchburg/Westminster, which in May 2007 brought on line the first two of five engines. Over the next eight years the Fitchburg/Westminster location will grow to eventually produce a total of 7.2 MW. Also, Granby, which already has in place a 2.8 MW system and a 0.1 MW system, is looking to add a third at 0.4 MW. Southbridge Recycling Park has a system that is expected to be in place by the end of the year and producing 1.6 MW.
Finally, Northampton (0.8 MW) and Haverhill (1.6 MW) are under construction with what would be their first gas-to-energy systems.
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