Offshore wind grid is the answer, study says
Pooling offshore wind power with one common grid would provide stability needed to rely on it as major electricity source, scientists find.
The solution to offshore wind energy obstacles lies in pooling all the power into one common electricity grid, according to researchers at the University of Delaware and Stony Brook University.
"We hypothesize that wind power output could be stabilized if wind generators were located in a meteorologically designed configuration and electrically connected," according to the report "Electric power from offshore wind via synoptic-scale interconnection."
Using hard data from 11 meteorological stations, the group tracked hourly how much wind blew over the last five years across a 2,500-kilometer area of the U.S. East Coast, and where it was consistently the strongest offshore. The scientists then created a theoretical wind grid based on the real-world wind behavior. It showed that had a wind grid existed over the last five years it would have neither reached full power nor reached an all-time low, but provided a steady source of electricity.
Despite seasonal shifts up and down in output from each individual offshore wind farm, the connected system allowed for a manageable stable power source, according to the results of the study.
The group concurred with the assertions that harnessing just two-thirds of the offshore wind power that potentially exists off the U.S. northeast coast could provide household electricity from Massachusetts to North Carolina, as well as electricity for lightweight vehicle fuel and building heat for those areas. But the group also agreed that offshore wind is challenging because of wind's naturally intermittent nature, and the expense of building and managing utility-scale storage for an intermittent energy source.
The group studied transmission versus utility-scale storage, and found that transmission between farms along a common grid was far more economical despite an initial cost layout to connect the Atlantic offshore wind farms with 3-gigawatt HVDC submarine cables .
The scientists' theoreticalat strategic meteorological points, and the transmission grid being placed to optimize energy sharing and efficiency. By this criteria, both the farms and transmission lines ended up being primarily placed in federal waters. The group conceded that such a setup might not be a politically popular one.
Many proposed wind projects would each connect separately to their adjacent state's electricity grid through a submerged power transmission cable, and the individual states would have power over them in conjunction with the utilities and regulating authorities. Many wind farm developers are alreadyin an effort to overcome local opposition and regulatory hurdles. If those wind farms were also interconnected in federal waters rather than solely connected to the adjacent state's shore, it would further shift political control away from the states.
"Today, generation of electricity is primarily a state matter, decided by state public utility commissions, whereas the Independent System Operators (ISOs) manage wholesale power markets and plan transmission. An ISO is the type of organization that might plan and operate the electric system we envision, probably with a mix of owners--private firms, existing electric utilities, and/or public power authorities," said the report.
"Because of the unique characteristics of building and operating offshore, and because our proposed Atlantic Transmission Grid would exist primarily in federal waters and bridge many jurisdictions on land, it may make sense to create a unique ISO, here dubbed the "Atlantic Independent System Operator," said the report.
Results of the study conducted by researchers at the College of Earth, Ocean and Environment at the University of Delaware and the School of Marine and Atmospheric Sciences at Stony Brook University were published in the April 5 issue of the journal Proceedings of the National Academy of Sciences (PNAS).