The Vieques Puerto Rico solar battery microgrid built by Cornell aims to cut electricity costs from 30 to 33 cents a kilowatt hour to around 15 cents, with hydrogen fuel cells planned by 2027 to stretch backup power to 10 days

A Vieques Puerto Rico solar battery microgrid answers an 18 month blackout

Vieques is a Puerto Rican island 8 miles east of the main island of Puerto Rico, home to 8,000 permanent residents. After Hurricane Maria struck in 2017, the island went 18 months without grid power from the main island, which Cornell calls the second longest blackout in world history. A Vieques Puerto Rico solar battery microgrid, a small power system built to keep running on its own if the larger grid fails, is meant to make sure that never happens again. The project is run by the Abruna Energy Initiative, a Cornell University research program led by chemistry professor Hector Abruna, funded by the 2019 class action settlement paid by Volkswagen.

Edgar Oscar Ruiz, executive director of the local nonprofit Community Through Colors, said the isolation of the island makes it especially vulnerable to problems on the main grid.

We're kind of at the end of the supply line, so anytime there are big power issues on the main island, we end up running into problems.

Edgar Oscar Ruiz, executive director of Community Through Colors, a Vieques nonprofit focused on emergency relief and long term resilience. Source 1.

A mobile battery already runs on Vieques, hydrogen fuel cells are next

A large, mobile, solar powered battery built by Buffalo based Viridi arrived in late 2025 at La Finca de Hamberto, a farm and resilience center on Vieques. It holds enough charge to power a small home for 3 days and already keeps 2 refrigerated trucks of food running through outages. A second battery is expected in May, and the project is also working to double its solar capacity, from 50 to 100 kilowatts, ahead of a hydrogen fuel cell system planned for 2027. Green hydrogen is hydrogen made using renewable electricity, which a fuel cell can turn back into power when the sun is not shining. Engineering reporting on the project states the fuel cells could stretch backup power from a few days on the battery alone to as long as 10 days, adding up to 2.5 megawatt hours, a unit measuring a large amount of stored electricity, of additional power.

The hydrogen fuel cell and larger battery storage will make the whole farm completely independent of any grid connection.

Hector Abruna, the Emile M. Chamot Professor of chemistry and chemical biology at Cornell and leader of the project. Source 1.

The plan could roughly halve electricity costs and keep the savings local

Abruna estimates Vieques residents currently pay 30 to 33 cents a kilowatt hour, the standard unit used to price electricity, and projects the finished microgrid will cut that roughly in half, to around 15 cents a kilowatt hour, once the batteries and hydrogen fuel cells are fully in place.

The savings would arrive as the wider Puerto Rico grid gets more expensive. The Puerto Rico Energy Bureau, the territory electricity regulator, ruled in a rate case that the fixed monthly grid charge, a flat fee every customer pays on top of the electricity used, would rise from 4 dollars to 8 dollars on July 1, 2026, and double again to 16 dollars the following year.

A project page published by the Abruna Energy Initiative states a goal that announcement coverage of the project does not mention, establishing what would be the second community based energy cooperative in Puerto Rico, meant to manage energy resources on the island and keep the economic benefit of the project on Vieques rather than with an outside operator.