The widespread power outages in the wake of Hurricane Sandy cast light on the weakness of a completely centralized electric power system and spotlighted the benefits of distributed power generation.
A number of locations reported that on-site power generation and the ability to operate independently of the grid allowed organizations, such as colleges and businesses, to stay at least partially online during the worst of the storm.
In many cases, back-up diesel generators are sufficient to keep businesses, such as stores and even data centers, operating during grid outages. People have been putting gasoline generators into service for their homes, too.
Microgrids are different in that they allow organizations to operate in “island” mode, or independent of the grid, for long periods. The two hurricanes in the east coast over the past two years and other heavy storms, including one approaching the northeast today, could generate more interest microgrid technologies, says Peter Asmus, an analyst at Pike Research.
“Smart grids are about reacting to storms and outages and limiting the amount of power outages. Microgrids are about stopping power outages from the get go,” Asmus says. “I think these storms are going to build interest.”
The Federal Drug Administration’s White Oak research facility in Maryland, for example, has gone onto island mode dozens of times since setting up a microgrid, according to building contractor Honeywell. During Sandy, the local grid failed and the campus facility switched entirely over to its on-site natural gas turbines and engines to power all the FDA buildings on the campus for two and a half days.
Campus or military bases are considered good candidates for microgrids, particularly if there is a strong need for back-up power. Princeton University typically gets its electric power from both from the local grid and an on-site cogeneration facility that supplies electricity and steam for heating.
During Hurricane Sandy, Princeton was able to switch off the grid and power part of the campus with about 11 megawatts of local generation, according to a report in the Daily Princetonian. By Wednesday night of last week, Princeton coordinated with local utility PSEG and reconnected to the grid, according to the report.
Similarly, a cogeneration plant at New York University was able to provide heat and power to part of the campus during Sandy in Manhattan, according to a report in the New York Times. The university invested in a cogen system, which are typically an efficient way to generate electricity and heat, to save money and reduce the university’s carbon footprint, but reliability proved to be a benefit during the outage, a university representative said.
Because of the low price of natural gas, cogeneration or gas turbines are often used for local generation and microgrids. But fuel cells that run on natural gas were also tested during Sandy.
The 23 stationary fuel cells from UTC Power installed in New York and New England were able to keep operating during the storm. A handful of those units were able to provide power when the grid went down and, as of yesterday, two were still running in “grid-independent” mode, according to the California Fuel Cell Partnership.
Local power generators and microgrids can also be used to provide electricity service to residential customers. During power outages from Sandy, a 40-megawatt combined heat and power plant in the Baychester section of the Bronx was able to provide electricity and heat to a large housing complex, according to a report in Forbes.
The natural gas distribution infrastructure is largely underground, making it more resilient to strong storms in places like the Northeast U.S. where most power lines are on poles. (See, Smart Meters Help Utility Speed Sandy Restoration.)
Microgrids in developed countries face a number of obstacles, including the upfront costs and regulatory barriers. And it’s not clear that business owners and real estate managers will start to plan for more severe storms, which are an expected outcome of climate change. (See, Climate Change Likely Makes Storms Like Sandy Worst.)
But Sandy was a harsh reminder of the dangers of massive power outages and the merits of using distributed generation to provide power independently of the grid.