Dive Brief:
- Green Mountain Power (GMP) expects to add three projects, totaling 14.4 MW of solar and 6 MW of energy storage, to the grid in order to reduce regional transmission costs.
- The Vermont Public Utility Commission (PUC) approved the first and smallest of the projects on Jan. 16. Sited in Essex, Vermont, the project's development and interconnection is expected to cost about $14.3 million.
- The project will address GMP's energy and capacity requirements as a load-serving entity in the ISO-New England electricity market, while helping meet the utility's Renewable Energy Standard obligations — using 75% renewable energy by 2032.
Dive Insight:
Vermont's only investor-owned utility has focused on cutting carbon emissions and energy costs. However, its projected power needs are too large to be "completely satisfied with cost-effective energy efficiency and demand resources," according to testimony included in the PUC order.
"[S]olar storage projects are a key way to drive down costs of the bulk grid, while increasing reliability for customers," Kristin Carlson, GMP spokesperson, told Utility Dive via email.
The PUC already approved the three projects in the utility's 2019 rate case. GMP agreed to "provide assurances" that the storage components' performance are good for customers, according to Carlson.
"These projects will provide value to customers by reducing peak costs, participating in ISO New England Frequency Regulation market, as well as providing renewable energy to serve our customers," Carlson said.
In order to take advantage of the available solar investment tax credits, the utility created a joint venture, GMP-Essex Solar/Storage (GESS), with a tax equity partner for the first project. GMP will own 60% of GESS, which will have a power purchase agreement (PPA) with the utility. The PPA will be among the lowest solar-plus-storage offerings at $0.099/kWh.
The Essex project will be tucked away, sited uphill without "visible neighbors," with over 18,000 solar panels and a Tesla Powerpack system, according to the filing. GMP's other solar-plus-storage projects will be about the same in size.
Proposed Projects
| Location | Solar | Battery |
|---|---|---|
| Essex | 4.5 MW | 2 MW / 8 MWh |
| Ferrisburgh | 4.99 MW | 2 MW / 8 MWh |
| Milton | 4.99 MW | 2 MW / 8 MWh |
SOURCE: Green Mountain Power
The projects are on track to be commissioned "before the end of the summer," she said. All three are based in the state's northwest region, around GMP's headquarters in Colchester, Vermont.
The Essex project's description allows the potential to use the storage system to island customers in the region from the bulk grid, noting that the area would need additional advanced microgrid control systems and equipment.
The utility had constructed a $10 million solar-plus-storage system in Rutland City, alongside other GMP solar projects, to help island an area that lost power during the 2011 Hurricane Irene.
