For a Resilient Power Grid, Think “Micro”

Wednesday, May 30, 2018

In most places, on most days, the ability to turn on a light relies on a large centralized power plant, a network of high-voltage transmission lines, and a local distribution system. Most people don’t even think about the electric grid that powers their everyday lives until suddenly it’s not there. Of course, that’s what happened in Puerto Rico and several other Caribbean islands after a series of devastating hurricanes last year. The system failures are shining a light on new solutions for the energy grid. Part of the answer may lie in microgrids. [Photo: Sunrun/Givepower]

More than eight months after Hurricanes Irma and Maria caused catastrophic damage in Puerto Rico, the island’s power grid continues to struggle, with occasional blackouts and many people still without regular electricity. “The rumble of generators now often drowns out the calls of the coquí frogs,” a blogger wrote recently in Scientific American.

But quieter energy solutions have also emerged, in the form of solar power and battery storage systems that have been installed at many school campuses, hospitals, shopping areas, and community centers.

“Microgrids are popping up everywhere, through absolute necessity,” said Christopher Burgess, project director for the Islands Energy Program at the Rocky Mountain Institute (RMI), which promotes renewable energy in the Caribbean. While these microgrids are still operating on an “almost boutique” scale, as Burgess put it, he believes they are “a precursor to a much larger investment in decentralized generation in Puerto Rico over time.”

Unlike an emergency gasoline generator that sits idle most of the time, a solar-powered microgrid is typically connected to the main energy grid, providing supplemental power generation on a regular basis. But if need be, it can be decoupled from the electric power system and run on its own. In other words, even if the main grid is down, microgrids can continue providing power to critical areas.

“After a hurricane, if you can get power to the cellphone tower, if you can get power to the water treatment and pumping station, if you can get power to the hospital and hurricane shelters, you’re doing pretty damn good,” Burgess explained in an interview. Despite some anecdotes about “solar panels flying around” during last year’s hurricanes, he said a new RMI study found that where the panels were properly engineered and installed, they survived the storms.

In the long term, Burgess believes that more countries will take a more “modular” approach to energy and incorporate microgrids into their power systems. Not only is this type of approach more resilient, he said; it’s also more cost-effective than a huge transmission and distribution system.

“The fully centralized approach is going away,” he said. “The new paradigm with all utilities, whether it’s a big continental grid or a small little island grid, is that you are going to have several locations of both generation and distribution that can decouple from the wider grid.”

Solar and battery microgrids are expected to be part of the energy picture on Barbuda; Burgess said plans are in the works to install such systems at two key sites on the island. Barbuda took such a hit from Hurricane Irma last September that its residents had to be evacuated to the sister island of Antigua, and most have yet to return home.

In Barbuda, where RMI is providing support through its Islands Energy Program, even the island’s normally sturdy diesel generators failed during Irma because they were located close to the shore and were flooded with saltwater, according to Burgess. The plan, he said, is to move the power station further inland and supplement the energy supply with solar power.

Distributed generation—electricity produced on or near where it is used, either for a single building or a microgrid—will likely become more common throughout the Caribbean, as countries hit by natural disasters look to “build back better,” to use former U.S. President Bill Clinton’s terminology.

With support from the Caribbean Community (CARICOM), the island of Montserrat is planning to integrate a 1 MW solar photovoltaic system into the existing 2 MW diesel-powered grid, according to

Dr. Devon Gardner of the CARICOM Secretariat. Parts of the solar power system will be installed on the roofs of strategic buildings and will be able to be isolated in case of an emergency.

The island nation of Dominica, which took a direct hit last year from Hurricane Maria, is also looking at options for distributed generation, according to Gardner, who noted that Dominica is continuing to pursue its plans for geothermal energy development despite setbacks from the hurricane. In March, the country launched the Climate Resilience Execution Agency of Dominica (CREAD) to manage its efforts to become the world’s first climate-resilient nation.

Advances in technology are making it easier for utilities across the region to integrate intermittent renewable energy sources and storage systems into energy grids, according to Dr. Gary Jackson, an independent energy consultant in the Caribbean. “Technology drives change in behavior,” he said.

Some wind power systems can now be shut down with the blades repositioned to prevent damage in a hurricane, Jackson said. He added that some smaller renewable energy systems are even collapsible so that they can be taken down before a hurricane and put up again after it passes, though he cautioned that these may not be as reliable as larger fixed systems.

Jackson believes that countries need to educate the public more so that people understand the need for resilience and high building standards and at the same time have realistic expectations. “We can’t project how Mother Earth is going to react in any given season,” he said.