Generating solar energy for the Laboratory, years in the making

Lincoln Laboratory unveils its 720-kilowatt solar photovoltaic carport.

By Kylie Foy | Technical Communications Group

Solar Panels MIT Lincoln LaboratoryA photovoltaic system consisting of 2,484 solar panels has been installed on the upper deck of the Lincoln Laboratory parking garage. Photo credit: Glenn Cooper.

It's hard to miss the newest addition to the MIT Lincoln Laboratory facilities: a gleaming array of solar panels affixed to the top of the parking garage. After three months of construction, the Facility Services Department (FSD) announced the official completion of the photovoltaic (PV) solar panel system on 27 January. The 52,000-square-foot, 750-kilowatt (kW) solar installation is owned and operated by a private investor, Onyx Renewable Partners L.P., without Laboratory investment, under an 18-year power purchase agreement (PPA).

"The Laboratory was looking for an economical way to create a commercial-scale PV system that could also be used to support energy research initiatives," said Dave Kiser, Energy Manager, FSD, explaining a significant motivation for the system. The project has its roots in an investigation conducted in 2012 by staff in the Laboratory's Energy Systems Group, and was later handed over to FSD in 2013. The Laboratory signed a PPA two years later with SunEdison, a milestone that concluded a period of complicated negotiations and approvals.

Kiser put the challenges into perspective: "Picture this environment," he said. "The Laboratory is asking a business to build, own, and operate a solar energy system on an Air Force base, on a facility that MIT owns, on a land leased from the government, during a period when MIT was negotiating the Laboratory's contract renewal, with all parties wanting limited liability." Last spring, the contracts were finally settled when the project hit a major road bump: SunEdison filed for bankruptcy. The PPA was soon transferred to Onyx Renewables, however, and construction began in October 2016.

The solar installation will reduce the Laboratory's carbon footprint. The electricity produced by the array will amount to about 1.3% of the total 75–80 million kilowatt-hours (kWh) consumed each year by the Laboratory's main complex, with higher production in the summer. The system will meet up to about 5% of the Laboratory's peak demand range, which is the maximum power requirement of a system at a given time.

Solar Panels MIT Lincoln LaboratoryLincoln Laboratory staff join Director Eric Evans for a ribbon cutting ceremony at the solar carport installation site. Photo credit: Glenn Cooper.

The project was mainly financed through the Solar Renewable Energy Credit (SREC-II) program, implemented by Massachusetts to help reach its goal of installing 1,600 megawatts of solar capacity in the state by 2020. With SREC-II, the energy produced by the Laboratory's system will earn Onyx Renewables credits that they can then sell on the market to electricity companies, who purchase those credits to count towards their renewable energy requirements. In addition to using SREC-II credits to finance the project, Onyx Renewables relied on a 30% federal income tax credit.

The PV system provides financial savings for the Laboratory as well. Electricity costs are comprised of two components: electricity consumption and demand charges. The Laboratory will purchase 100% of the electricity produced by the system at a fixed, non-escalating rate of 16.5 cents per kWh. While the average cost of electricity through Eversource is about 13.6 cents per kWh, significant savings occur when analyzing the other half of the electric bill: demand charges. The Laboratory expects to avoid an estimated $260,000 in electrical demand, supply, and miscellaneous costs, while purchasing about $170,000 of electricity annually from Onyx Renewables through the PPA, saving approximately $90,000 per year.

Employees may have already noticed a side benefit of the array, as well: covered upper deck parking, providing protection from snow, rain, and sun.

Solar Panels MIT Lincoln LaboratoryThe solar panels were installed on the roof of the Laboratory parking garage. Photo credit: Glenn Cooper.

"This was an extraordinarily complex project to bring to completion and was successful only due to a dedicated team effort. The administrative coordination and approvals were nearly overwhelming; the contracting vehicle of the PPA was new to the Laboratory and the industry. And after nearly three years of effort, the bankruptcy of SunEdison was to many the death song," Kiser reflected. "So, seeing it completed really feels good."

Looking forward, staff are continuing to research opportunities for installing additional PV systems on other buildings, potentially quadrupling the amount of solar energy generated for the Laboratory.

Posted April 2017

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