Portland and South Portland officials have teamed up to negotiate joint proposals to build solar arrays on former landfills in each city later this year.

The officials are in talks with ReVision Energy of Portland after the company responded to separate advertised requests for proposals from each city last fall.

South Portland turned down its proposal from ReVision, one of two that the city received and rejected, and is negotiating with the company under more favorable terms that were offered to Portland.

The pending deal stands to save the neighboring cities money and time in furthering similar solar power and sustainability goals. The cities would have separate contracts and operating agreements, but they would save on the cost of designing, engineering and building the photovoltaic systems and in buying materials in bulk.

“We broached the idea of a joint proposal and ReVision was interested,” said Troy Moon, Portland’s environmental programs manager. “If there are opportunities for us to collaborate on this project and benefit from certain economies of scale, it helps build a bridge to doing more projects together in the future.”

The joint effort expands an existing relationship between the cities that recently got a boost when Jon Jennings became Portland’s city manager after working for two years as assistant city manager in South Portland, where he worked with City Manager Jim Gailey.

South Portland rejected two proposals received in October from firms willing to develop and operate solar arrays on municipal properties, including its 34-acre former landfill off Highland Avenue.

One of the proposals came from Ameresco Inc. of Framingham, Massachusetts, and the other came from ReVision and Energy Systems Group of Newburgh, Indiana. Neither bid offered an appealing power-purchase agreement nor addressed the city’s desire to install solar panels on nine municipal buildings, such as City Hall, the public library and the community center.

At the time, Gailey noted that other communities had received more favorable proposals, though he declined to name them, and he said city staff members were re-evaluating South Portland’s solar energy options before moving ahead with an alternative plan.

Since teaming up with Portland, South Portland officials have decided to focus on developing the landfill solar array ahead of other solar facilities. ReVision installed solar panels on the city’s planning department buildings several years ago.

“At some point we will double back to the rooftop projects,” said Julie Rosenbach, South Portland’s sustainability coordinator.

SIMILAR LANDFILL ARRAYS

The size and generating capacities of the solar arrays on each landfill are expected to be essentially identical to ReVision’s initial Portland proposal. The cities are negotiating power-purchase agreements that would dictate how much they would pay ReVision for electricity generated by the arrays and how much they would pay to purchase the arrays in the future.

Received in November, the Portland proposal called for installing solar panels on the city’s 44-acre former landfill off Ocean Avenue and on four public buildings: Portland Arts and Technology High School, King Middle School, the Portland International Jetport parking canopy and the Portland Public Library’s storage facility on Riverside Street. Portland is now negotiating separately for the rooftop projects.

Under the initial proposal, ReVision would build a 660-kilowatt array on Portland’s landfill that would serve a maximum 10 municipal meters – the largest possible under Maine law. Legislative efforts are underway to lift those caps.

As a for-profit company, ReVision would receive a federal solar investment tax credit, which would give the company a tax reduction equal to 30 percent of the $2.6 million project. The cities aren’t eligible for the tax credit because they are nonprofit entities.

The system in the initial proposal would generate 1.2 million kilowatt-hours of electricity annually, or about 3.5 percent of the 35.6 million kilowatt-hours used by Portland’s municipal and school facilities each year, Moon said.

Under a negotiated power-purchase agreement, Portland would pay ReVision a premium for electricity generated by the solar array, which would be about 3.5 cents per kilowatt-hour higher than its current municipal rate of 8 to 9 cents per kilowatt-hour.

If Portland purchased the solar array after seven years, which is allowed under federal tax credit law, the city’s electricity costs would drop to about 6 cents per kilowatt-hour, saving about 2 cents per kilowatt-hour over the 40-year life of the panels, Moon said.

A similar system on South Portland’s landfill would generate nearly 12 percent of the 10.1 million kilowatt-hours used by its municipal and school facilities, Rosenbach said.

REDUCING CARBON DEPENDENCE

The solar arrays would be installed on concrete pads that would avoid piercing the capped landfills, said Fortunat Mueller, managing partner of ReVision Energy. The company recently completed the first solar installation on a municipal landfill in Maine – a 128-kilowatt system in Belfast that went on line in January.

Mueller said his company was eager to work with the two cities and hoped to have the Portland and South Portland projects on line by fall. The initial Portland proposal called for 2,916 solar modules measuring 39-by-77 inches that would be arranged in 10 rows.

“The two landfill projects are so similar, it makes sense from our perspective that there can be similar designs and similar economies of scale,” Mueller said. “Hopefully, it means both cities can get a better deal.”

Portland City Councilor Jon Hinck, who heads the council’s energy and sustainability committee, said developing significant solar generation facilities is a critical step toward reducing carbon-based fuel use at a time when solar energy is increasingly more competitive.

“Solar is a good hedge against other power that can be much more variable and the environmental benefits of clean energy are recognized by many people in both communities,” Hinck said. “We want to reduce our carbon footprint and be part of the clean energy revolution.”