How much a microgrid costs for affordable housing in two feasibility studies
How much a microgrid, a small power system that can keep specific buildings running when the wider electric grid goes down, costs for affordable housing is the question behind 2 feasibility studies the Massachusetts Clean Energy Center paid for in Chelsea and in the Chinatown section of Boston. The state agency funded feasibility studies for 14 community microgrid projects across Massachusetts in February 2018, spending 1.05 million dollars combined, and Chelsea and Chinatown are 2 of the 14. Clean Energy Solutions, the engineering firm the state hired, wrote both reports, filed the same month, June 2020, using the same modeling method, called DER CAM, in each one.
The 2 reports came back with an identical number, 6 million to 8 million dollars in capital cost, the money needed to design and build the solar panels, batteries and wiring themselves, for each project. That match only becomes visible once both reports are read side by side, because the buildings each study names use very different amounts of power. The 3 Chinatown buildings, Castle Square Apartments, a 500 unit tenant owned complex, 65 Harrison, and the Josiah Quincy Elementary School, together need 2,235 kilowatts at their summer peak, a kilowatt being the standard unit for how fast a building draws electricity. The 3 Chelsea buildings, Buckley Apartments, a 210 unit public housing tower for elderly and disabled residents, the Beth Israel Deaconess Medical Center, and Chelsea City Hall, need 570 kilowatts combined. Chinatown needs nearly 4 times as much power, and the state got the same price for both.
Castle Square Apartments, the Josiah Quincy Elementary School and 65 Harrison are named in the Chinatown feasibility report, source 3. Buckley Apartments, the Beth Israel Deaconess Medical Center and Chelsea City Hall are named in the Chelsea feasibility report, source 4.
Show the numbers
| Castle Square Apartments | 1,540 |
| Josiah Quincy Elementary School | 550 |
| Buckley Apartments | 275 |
| Beth Israel Deaconess Medical Center | 180 |
| 65 Harrison | 145 |
| Chelsea City Hall | 115 |
Why the same estimate covers very different power needs
The match suggests Clean Energy Solutions carried a template cost range from one study into the next rather than calculating a fresh figure from each site own equipment needs. Neither report says this about itself. Both reports also calculate an identical 200,000 dollars in upfront working capital a microgrid operator would need to launch, again the same number for a project using nearly 4 times more power than the other. For a state program deciding how to fund community microgrids, a feasibility estimate this uniform is a starting placeholder, not a number to build a construction budget against.
The Chinatown total is 1,540 plus 145 plus 550 kilowatts from source 3. The Chelsea total is 275 plus 180 plus 115 kilowatts from source 4. Both totals are this publication own addition of the figures above, not a number either feasibility report states directly.
Show the numbers
| Chinatown study total | 2,235 |
| Chelsea study total | 570 |
What Chelsea and Chinatown have built since
By 2023, the Chelsea City Council had approved actual funding, not a feasibility estimate, 4 million dollars for 400 kilowatts of solar panels and 500 kilowatt hours of battery storage at its police station, city hall and public works yard.
We do see this serving as a model for the nation if we can pull it off.
Alexander Train, director of housing and community development for Chelsea. Source 2.
The Chinatown project changed shape instead of growing at the same pace. It narrowed from the 3 buildings the 2020 study named down to 1, Masspike Towers, an affordable housing building with 190 units.
Our goal is to bring the benefits of clean energy and decarbonization incentives to a low-income urban community that has historically missed out on a lot of those benefits.
Lydia Lowe, executive director of the Chinatown Community Land Trust. Source 2.