Madison ESS
Battery storage power plant · Somerset County, Maine
Nameplate capacity
4.9 MW
Rank in Maine
#142
of 274 plants
In service since
2019
June 2019
Details
- Primary fuel
- Battery storage
- Technology
- Batteries
- Operator
- Agilitas Energy, Inc.
- County
- Somerset County
- Generating units
- 1
- Share of state capacity
- 0.08%
- Rank among battery storage plants in Maine
- #3 of 5
- EIA plant code
- 64765
Generating units
| Unit | Technology | Nameplate | Summer | Online | Status |
|---|---|---|---|---|---|
| MESS | Batteries | 4.9 MW | 4.9 MW | 2019 | Operating |
Nameplate is the maximum rated output; summer capacity is what the unit can reliably deliver on a hot day, which is typically lower.
Similarly sized plants in Maine
| Lewiston Junction Road Solar | Solar | 4.9 MW |
| Lincoln ME 1 | Solar | 4.9 MW |
| Pittsfield Solar (N. Main St) | Solar | 4.9 MW |
| Rumford ESS | Battery storage | 4.9 MW |
About this data
From EIA’s inventory of operable generators, May 2026 release. Capacity is nameplate — the maximum rated output of the equipment, not what the plant actually generates over a year, which depends on how often it runs. A 4.9 MW solar plant and a 4.9 MW nuclear plant have the same entry here and produce very different amounts of electricity.
“In service since” is the earliest in-service date among the units still listed, so a site rebuilt around newer equipment can read as younger than the site itself. All Maine power plants · What Maine actually generates