According to a new study performed by academics at North Carolina State University, offshore wind power might help cut wholesale electricity prices in six New England states on average, with minimal risk of wind turbines collapsing during severe winter storms.
Although very high wind speeds during winter storms may cause turbines to go offline briefly, they discovered that the greatest danger of unexpected wind power outages occurs in the summer when wind speeds are at their lowest.
The findings, which were published in the journal Energy, could help New England utilities, politicians, and customers figure out what to expect in terms of price and reliability from adding offshore wind power to the region.
“Adding offshore wind to this market reduces wholesale prices for electricity overall and reduces emissions pretty consistently,” said Jordan Kern, assistant professor of forestry and environmental resources at NC State.
“When we consider these bad winter storms, the cases are rare when you’d lose wind power due to excessively high wind speeds, and even then it doesn’t break the system or cause a shock to the market. A bigger issue we identified is what to do in the summertime, when it’s really hot, and wind speeds are low.”
New England aims to install significant extra wind power capacity, with offshore and onshore wind farms accounting for up to 60% of anticipated new power generation. The nation’s first big offshore wind farm, a 30-megawatt farm off the coast of Rhode Island, is already located in the region.
While wind power is considered to be a “savior” during severe winter storms, researchers sought to see if storms could interrupt electricity supplies and push up prices because turbines shut down at wind speeds over 55 miles per hour.
We were looking to see if there would be blackouts because of this sudden lack of energy from offshore wind power plants, but we didn’t see a case where the system went into a blackout in any of the scenarios we evaluated. Most of the time during winter weather events, having wind is a good thing because the wind speeds are high. Only rarely did the wind speed get so high that the wind turbines shut off completely.
Kerem Ziya Akdemir
“Land-based wind power makes up most of all wind power in the U.S.,” Kern said. “A lot of that is located in the middle of the country. If you live on the East Coast, though, land is expensive, and wind speeds are lower. That’s when offshore starts to look good.”
Researchers utilized a power grid model to evaluate the influence of more wind generation on power prices in six New England states: Connecticut, Maine, Massachusetts, New Hampshire, Rhode Island, and Vermont during a cold spell in December 2017 to January 2018. Because of the “bomb” cyclone, electricity consumption and natural gas prices skyrocketed during the storm.
Even though the turbines switched off on one day owing to the cyclone storm, they discovered that adding offshore wind power reduced the severity of price surges during the cold snap.
They discovered that if there had been an additional 4,000 megawatts of offshore wind power online during the storm, wholesale prices would have reduced by $28.81 megawatts per hour on average.
“We were looking to see if there would be blackouts because of this sudden lack of energy from offshore wind power plants, but we didn’t see a case where the system went into a blackout in any of the scenarios we evaluated,” said the study’s lead author Kerem Ziya Akdemir, a graduate student in forestry and environmental resources at NC State.
“Most of the time during winter weather events, having wind is a good thing because the wind speeds are high. Only rarely did the wind speed get so high that the wind turbines shut off completely.”
They also looked at how adding 800 or 4,000 megawatts of offshore wind power would affect power prices over 69 years, from 1949 to 2018, compared to not adding any new offshore wind capacity. Adding wind power to the mix reduced the average wholesale price of electricity over the research period.
“We observed that if we increase the offshore wind capacity in the region, generally the wholesale prices will be lower,” Akdemir said.
“There were one or two instances where we observed very, very high prices because excessive wind speeds caused the turbines to cut off, leading to a sudden loss of wind power in the region, but those did not have very serious consequences for the New England electricity grid.”
During cut-out occurrences, when the turbines were turned off, costs climbed by an average of 89 cents per megawatt-hour in the scenario with the highest wind power added.
The highest prices in the investigation were not caused by cut-out incidents caused by strong wind speeds. During the summer months, when individuals use a lot of power to cool their houses and wind speeds are low, the most frequent and dramatic price hikes occurred.
“In the wintertime, there’s a little bit less demand for electricity than in the summer, so there’s some other power plants that can kick on and replace the wind quickly,” Kern said.
The researchers looked at electricity wholesale rates, and they noted the topic of how wind generation might affect consumer power costs is still open.
“The findings overall suggest that adding wind offshore to the system almost all the time will result in lower market prices and lower emissions,” Kern said.
“Whether that means that consumers will pay less for electricity is a much trickier question. It’s not cheap to build offshore wind farms; you have to build them in the ocean. Consumers could have to pay for that.”
The study was published online in Energy and titled “Assessing risks for New England’s wholesale electricity market from wind power losses during extreme winter storms.”
Jonathan Lamontagne of Tufts University was a co-author on the paper. The work was supported by the US Department of Energy’s Office of Science as part of the MultiSector Dynamics, Earth and Environmental System Modeling Program’s research.
