A quantitative analysis of offshore wind energy on the U.S. East Coast finds that, in theory anyway, the strong winds there could potentially meet one third of the entire country's electrical demands.
The study, "East coast U.S. offshore and near shore wind energy potential" concluded that the offshore wind energy available in the Atlantic Ocean off of the east coast is sufficient for powering much of that region:
"A major finding is that the strong winds off the USEC alone can theoretically power all of the annual coastal electricity demand from Florida to Maine (FL-to-ME) or about one-third of US electric power demand. With the exception of summer, all peak-time electricity demand could be satisfied in the states of Virginia through Maine (VA-to-ME) with OWE in those states’ waters."
The team used weather modeling to generate five years worth of hourly wind speed data for locations at 90 meters above the surface (the height that an offshore turbine would reach) and then added turbines into the model. The 140,000 5 MW wind turbines were "installed" at varying distances and depths, covering the area from Maine to Florida.
For their analysis, the team found that after figuring in the standard losses in turbine inefficiencies and transmission, offshore winds on the east coast could produce up to 1,372 TWh of electricity annually, and that even more importantly, it could produce it at the best time - during peak demand.
While we're a long time away from installing 140,000 offshore wind turbines, the data shows the potential is there, and could be used to help guide wind farm placement by locating areas with high wind energy potential near high population areas.