One site in Canton, Massachusetts will get Solar Treatment of 5.6 megawatts of solar photovoltaic panels over the top of a capped landfill along with Southern Sky Renewable Energy.Which is expected to generate $70 million in combined savings and revenue over the next 25 years. The report says it will be the largest solar installation in New England once completed.

The land lay unused until last year, when the town decided to turn it into a largest solar power array

“Capped landfills have turned out to be a prime location for solar panels since they tend to be raised, can’t be built on and have to be clear of trees to protect the integrity of the lining.”

Across the state many communities including Attleboro and Norfolk, are planning to install solar panels on their landfills. Norfolk expects to save about $250,000 a year in energy costs from a solar energy project – also by Constellation Energy – planned for the former town landfill site off Medway Branch Road.

In Norton, a firm last year had been looking into a solar energy farm at the townn’s capped Hill Street landfill. Voters at a June 2009 special town meeting authorized selectmen to lease the landfill for a solar project.

Southern Sky Renewable Energy, the company that installs the 24,000, 3-foot by 5-foot panels, are expected to generate up to 5.6 megawatts of power by 2012. The key to the project’s finances is the state’s Solar Renewable Energy Certificates program, established to help the state reach a goal of producing 250 megawatts of solar power by 2017. The state is currently producing about 76 megawatts.

Southern Sky Managing Director Frank McMahon said the project is the company’s first on a landfill.

“We’re hoping to start construction in late spring, based on snow and a final agreement with NStar,” said McMahon, referring to the utility that will buy the power.

To guarantee the value of the credits, the state sets a minimum of about $285 for each credit, although the price can rise as high as $550.

A one megawatt project can produce about 1,140 megawatt hours of power a year. If those 1,140 credits were auctioned at the minimum of $285 each, that would translate into nearly $325,000 in credits annually.