Leveling out such fluctuations remains the biggest obstacle to widespread wind power use, according to a study by University of Delaware and Stony Brook University researchers, which was published this week in the Proceedings of the National Academies of Sciences. The study says:
"As wind power becomes a higher proportion of all generation, it will become more difficult for electric system operators to effectively integrate additional fluctuating power output. Power fluctuations are important if wind is to displace significant amounts of carbon-emitting energy sources."The group studied 5 years of wind data from 11 meteorological stations spanning 1,550 miles of coastline off the eastern U.S. While each station showed the expected ups and downs depending on how the wind was blowing, simulating a power line connecting the stations showed a leveling of this fluctuation. The researchers say in the study:
"The output from the entire set of generators rarely reaches either low or full power, and power changes slowly. Notably, during the five-year study period, the amount of power shifted up and down but never stopped."Existing projects for offshore wind power are authorized at a state level and involve connecting the wind power to land grids separately, making it difficult to manage the fluctuating power from each individual project. Typically, this is done with mechanisms, such as reserve generators, redundant power line routes and ancillary service markets.
However, the authors note that problem could be avoided if all offshore generators were connected in their own power grid. Such an Atlantic Transmission Grid, managed by its own Independent System Operator (ISO), could provide a reliable source of power for all adjacent states.