Giant Batteries for a More Resilient Provincetown
A visit to Eversource's Outer Cape Battery Energy Storage System
On a cold and rainy September morning, I traveled with a small group of MIT students to the quaint seaside village of Provincetown, Mass., to visit a giant battery.
This wasn’t a sightseeing trip. Skipping the art galleries and beaches, our group instead headed to Eversource’s first-in-the-nation Outer Cape Battery Energy Storage System (BESS), which provides backup power to 11,000 homes in the outer part of Cape Cod. The BESS is the first single battery in the nation to provide power to a microgrid of this size, according to Eversource.
Our trip was organized by Proto Ventures and the MIT Energy and Climate Club to learn more about the role of energy storage units in renewable energy innovation. While there is much excitement around cutting-edge storage units for increased renewable energy penetration, our visit underscored that storage units will arguably serve a more important role in the short term for resilience and climate adaptation.
The BESS facility may look unassuming, but its simple exterior belies a first-of-its-kind implementation. Underground cables feed into transformers that connect to a large room filled with over 10,000 lithium-ion battery units. These modules are supported by sophisticated temperature regulation systems and hazard response mechanisms, all working together to keep the batteries functioning safely and efficiently. The $49 million, 25-megawatt facility operates almost entirely autonomously, save for the occasional maintenance check by engineers.
Batteries for a Cleaner Grid
Grid storage units like these are traditionally seen as an integral part of the energy transition. The "duck curve" phenomenon, driven by the growing penetration of renewables, results in a dip in net load during the afternoon and steep ramps during evening peak hours. This variation creates price volatility, which many players in wholesale energy markets hope to exploit through optimal charge and discharge.
Beyond revenue maximization, long-duration storage will become crucial to meeting demand during high-net load hours in a market with high renewable energy penetration. Long-duration storage will charge in the afternoon, when solar units are being curtailed, and will discharge through the evening and into the morning, while the sun doesn’t shine and the wind doesn’t blow.
The race for long-duration storage has led to a hotbed of innovation, with companies like Form Energy and Antora Energy (industrial heat) commercializing technological innovation to bring down the cost and increase the round-trip efficiency of long-duration storage. Massachusetts recently approved two additional Eversource energy storage projects that will provide a total of 800 MWh to the grid.
Barriers to Batteries
Despite the promise of both short and long duration storage, there are challenges to adoption. For one, the appeal of grid-scale storage is premised on the idea that there will be plenty of ultra-cheap renewable electricity to charge up the batteries. So far, that hasn’t been the case. In Massachusetts in 2022, only 10 percent of electricity came from solar, wind, and geothermal combined. And across the United States in 2024, supply chain uncertainty and workforce shortages have flattened growth for new solar modules . Further down the value chain, interconnection backlogs for new projects is an alarming bottleneck, to the extent that only 14 percent of the generation capacity of all the projects that submitted interconnection requests from 2000 to 2018 had been built and brought online by the end of 2023. Transmission capacity growth remains slow, and projects’ capital costs may change rapidly even through the course of their development cycle due to macroeconomic factors.
Eventually renewable energy supply will catch up, and that’s when the technological advances from BESS and similar batteries will make the most impact. The relative shortage of ultra-cheap renewable electricity somewhat limits the viability and profitability of large scale storage units in the short term. Eversource may eventually leverage facilities like the BESS plant to participate in ancillary services markets and energy arbitrage. But for now, its primary purpose is to provide redundancy for something as severe as a Nor’easter to unfortunate incidents of inattentive drivers knocking out power poles.
BESS as a Bridge for Resilience
And yet, those are not the reasons Eversource built the BESS — it’s redundancy. Resilience is of particular concern in Cape Cod, in no small part due to its unique energy distribution infrastructure. The entire stretch between the BESS facility on Race Point Road and Provincetown is powered by a single 13-mile power line, making it vulnerable to disruptions. This lack of redundancy is made more alarming by the fact that the outer Cape is often subject to extreme weather due to strong winds coming down the Atlantic shore.
Standing at the facility on that Saturday, I knew what Eversource faced and why this battery was so important. We had just driven along this two-lane coastal highway, past the wind-swept beaches and cranberry bogs. The ocean was so close we could see it around each turn, even through the sculpted hedges and cedar-shingled houses. I’d heard that during a particularly bad blizzard in 2022, nearly the entire Cape lost power for more than a day.
The traditional solution in such cases is to build an additional distribution line along the coast. However, permitting challenges, environmental impacts, unforeseen capital costs, and nimbyism often hinder grid infrastructure projects. As one Eversource engineer put it, "a multi-year, multi-million-dollar grid project can be halted by one town council meeting."
In this context, Eversource's BESS facility offers a practical interim solution. The facility functions as the sole supply source for a microgrid back to the substation. The microgrid design includes 17 pole-mounted recloser controllers that provide fast fault isolation and dynamic distribution circuit automation in response to temporary and permanent faults to minimize customer outages. The system can turn on battery power for up to two hours in high-peak summer demand and up to 10 hours during low-demand periods.
The Future of BESS in Climate Adaptation
As a part of its state-approved grid modernization plan, Eversource received regulatory approval to recover $50 million for a 25 MW / 37 MWh battery plant. That translates to around $1,350/KWh, which is more than twice the average sticker price for lithium-ion two-hour storage plants. Given the high sticker price of the unit, and its modest deployment, it is worth examining if it is worth it.
Over the past 20 years, Massachusetts has seen an uptick in power outages, in no small part due to extreme weather events. Based on outage data reported by utilities, and depending on our estimation methods, we may assume that by 2030, Massachusetts could be seeing 20-50 outages per year.
Conservatively, we may estimate that most of these outages will last for 2-3 hours (although reports indicate that in addition to frequency, outage durations will increase). Thus, we can calculate the economic cost of outages offset by the plant in the near future:
Assuming a 10-year lifespan from 2022 to 2032, and with a sticker price of $50 million for the project, the implication is that it costs Eversource between $5 to $11 in capex to service an hour’s worth of outage for each household.
If these numbers appear high, that is because they are. They bely both direct and indirect costs of outages for households, from food preservation–the cost of replacing all the food in one’s fridge alone could top hundreds of dollars–and productivity loss to externalities such as critical services loss and health and safety hazards. Moreover, unreliable power supply can have lasting impacts on industries like tourism, which is a large source of revenue for the Cape.
These calculations highlight the urgency of addressing the climate crisis before we find ourselves having to completely pivot our survival strategies toward adaptation. According to the UN Environment Program’s 2023 Adaptation Gap Report, implementing adaptation strategies on a national level may cost over $380 billion per year. Working to proactively build resilience solutions, such as microgrids and distributed energy, will complement ongoing efforts in mitigation and emissions reduction to ensure an affordable and livable future for everyone.
What this means for MIT
This visit to the BESS facility highlighted several key insights for the MIT energy community. While there is much excitement around innovation in renewable energy technologies, the deployment of storage units like BESS reveal the crucial role that storage may play in the short and medium term as a non-wires alternative for resilience and adaptation, instead of load balancing in a highly decarbonized grid.
For MIT students and clean energy enthusiasts like me, understanding the challenges of integrating storage units into existing grid infrastructure is crucial. As we work toward unlocking new solutions, the success of ventures like Eversource’s BESS serves as a reminder that technological innovation alone is not enough. Navigating regulatory, economic, and social obstacles is just as essential in building a more resilient and sustainable future.
We would like to thank Anuj Mathur from Eversource for graciously hosting this visit to the BESS facility.
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