Often communities don’t even start to think about microgrids until after a disaster, giving rise to the adage ‘follow the carnage’ to describe a common path to microgrid development. But in the Bahamas, if there is any good news, it’s that microgrids were already on their way before Hurricane Dorian.
The head start is a result of collaboration between the Rocky Mountain Institute (RMI), the Bahamas government, and Bahamas Power and Light (BPL), a publicly-owned utility that serves 21 of the islands. (Grand Bahamas, which includes Freeport, is powered separately by a subsidiary of Emera.)
RMI has been working with BPL and the government since 2015 on a least-cost pathway to reduce the islands’ reliance on diesel generation. The team is focused on the inhabited areas of the Family Islands, a string of 700 islands in the Bahamas also known as the Out Islands.
The plan calls for transitioning the islands to solar and storage by phasing in projects as technology costs drop, said Christopher Burgess, director of projects for RMI’s Islands Energy Project.
When Dorian struck, the team already had their first microgrid well along in planning. The microgrid is being developed on Ragged Island, a small community of about 100 people in the southern Bahamas, which saw much of its energy infrastructure destroyed two years ago to Hurricane Irma.
Challenges caused by Dorian
The Ragged Island microgrid is designed to withstand severe storms. It will be built on high ground with underground wiring, Burgess said. Salt Energy, based in Key West, Florida, won the project’s engineering, procurement and construction contract through a competitive solicitation.
Despite Dorian, Burgess expects the Ragged Island microgrid to be completed on time this winter. Needless to say the hurricane has made the deadline more daunting.
The team had to divert German components for the microgrid that were enroute to Freeport. Instead, they’ll arrive in Miami. The status of precast foundations remained unsettled when Microgrid Knowledge interviewed Burgess last week. A Bahamian company in Freeport won the contract, but given the destruction in the city, Burgess was unsure if they could fulfill it. “My guess is that we’ll have to source the precast foundations from Florida,” he said.
The Ragged Island microgrid is particularly important because it is designed to RMI’s “solar under storm” best practices. The project also attempts to demonstrate how the Bahamas can transition away from diesel fuel, Burgess said.
“This microgrid, because of where it is, and how expensive diesel is, is going to be 93% solar with a large battery to keep everything stable,” Burgess said.
Once the microgrid is installed, the island should need diesel generators no more than a couple of hundred hours annually, a small run out of a year’s 8,760 hours. The microgrid is built to serve the island’s load with 390 kW of solar photovoltaics and a 3,000 kWh long-duration battery.
The Ragged Island microgrid is important because it derisks and demystifies solar-storage microgrids in the Carribean, Burgess said.
“You’ve got utilities and governments who’ve only known diesel centric generation since they were electrified in the 1930s and 40s. To do something completely different, with solar and battery as your primary generation source, it’s a little scary for them,” he said.
Because it is small, Ragged Island offered an ideal location for a prototype microgrid — a place where the team could “get through the kinks and operations,” establish standard operating proceedings and train utility staff. “Now you can roll that out as a program and portfolio to the other islands,” he said.
Part of larger effort by the Bahamas government
The Ragged Island project is a followup to a 925-kW Category 5 Hurricane-worthy solar carport commissioned by the government in April at the Thomas A. Robinson National Stadium in Nassau.
“They are using that as an EV charging asset, and they can isolate that circuit if they need to. So that could be a source of critical power, and it’s right there in the center of town,” Burgess said.
The government of the Bahamas also went live a few weeks ago with a solar installation at a high school in Nassau. And solar projects are planned for an elementary school and the Office of the Prime Minister.
The solar installations will later be paired with energy storage with the intent of eventually giving them the ability to decouple from the grid and provide critical power directly to the buildings during emergencies like Dorian.
The utility also has an open call for solar-storage capacity on four of the Family Islands: Andros, Bimini, Eleuthera and Inagua.
How to build more microgrids
Burgess sees all of these projects as the first phase of the islands’ microgrid effort, which will only accelerate due to Dorian. But the Bahamas are not wealthy and setting the stage for microgrids on the far flung islands is not easy.
So in the wake of Dorian, RMI has kicked off a fundraising drive to accelerate its pre-development work, a crucial step to attract private companies to handle microgrid design and construction by way of competitive tenders.
RMI plans to seek out new areas to host solar and storage microgrids, but “it’s expensive in the Family Islands — you have 21 islands, and you’ve got to do at least 21 geo-techs, 21 interconnection studies, 21 site surveys…” Burgess said.
And time is of the essence. Burgess said his colleagues on the island report that Dorian flattened utility infrastructure, creating massive power outages that add to the struggle faced by island residents, many homeless and now without income. Microgrid technology is on its way, just not fast enough.
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