A team of researchers from Cornell University is betting that a green hydrogen microgrid will be the key to stabilizing and lowering the cost of power for the nearly 8,000 residents of Puerto Rico’s Vieques Island.
Located about eight miles to the east of Puerto Rico’s main island, Vieques has long been vulnerable to extended power outages. After Hurricane Maria swept through in 2017, it took nearly 18 months for grid power to be restored via the lone underground cable from the main island.
A decade of power issues
Nearly 10 years on, life on Vieques is still not back to normal. Power outages and brownouts persist, with voltage fluctuations causing nearly daily brownouts that can damage appliances and sensitive electronics beyond repair.
The grid electricity that does make its way to the island is some of the most expensive in the U.S. Residential electric prices on Vieques average $0.34 per kWh. By comparison, those on the main island pay closer to $0.27 per kWh. Ratepayers in the 50 U.S. states pay $0.18 per kWh on average.
The island’s residents and businesses have been forced to rely on diesel backup generators to power their lives, but that too is becoming cost prohibitive. On Vieques, diesel prices run especially high because of the Jones Act, a 1920 law requiring shipments between U.S. ports to travel on U.S.-built, U.S.-crewed vessels.
Microgrids to the rescue
Solar and energy storage projects are becoming more prevalent across the U.S. territory. In 2023, the Puerto Rico Electric Power Authority (PREPA) was awarded $10.2 million from the Federal Emergency Management Agency to build two solar-powered microgrids, including a 12.5 MW system on Vieques.
Last year, a solar and battery storage microgrid was installed at La Finca de Hamberto, a USDA Organic farm and resilience center, where it powers refrigerated semi-trailers used for food storage and provides locals with access to power during grid outages.
The community-owned microgrid was the first phase of a broader initiative led by Héctor Abruña, a chemistry professor and researcher at Cornell University, and founder of Abruña Energy Initiative (AEI). Abruña was born in Puerto Rico.
AEI and its community partners have big plans for the microgrid. The site’s solar array was expanded from 50 kW to 100 kW earlier this year, adding additional capacity and a shady spot for the farm’s chickens to roost.
A mobile battery from New York-based Viridi, a battery energy storage systems provider, was also added this spring to store excess energy.
Next up, green hydrogen
The team plans to add an on-site green-hydrogen fuel cell system in early 2027. A solar-powered electolyzer will extract hydrogen from water. The hydrogen will be compressed and stored in onsite gas cylinders, ready to feed mobile fuel cells that can be deployed across the island as needed.
The hydrogen system, from Nel Hydrogen, will extend the microgrid’s capabilities by providing power when its solar panels cannot — like in the aftermath of hurricanes when cloud cover diminishes solar production. With 2.5 MWh of hydrogen storage, it can stretch the microgrid’s capacity from a few days to as long as ten.
It will also ensure the local fire station, health clinic and other critical infrastructure such as drinking water pumps and the refrigerated trucks, have power when they need it most.
While green hydrogen systems often don’t pencil out, the high cost of grid power and diesel fuel on Vieques make it a prime candidate for the technology. Abruña predicts the system could cut electricity rates on the island in half.
Similar hydrogen-solar-battery hybrid microgrids are being tested in Scotland and Southern California. In Florida, Duke Energy is producing and blending green hydrogen into its power generation mix.
