Where is the ideal location for a US East Coast offshore grid?

Abstract

1] This paper identifies the location of an "ideal" offshore wind energy (OWE) grid on the U.S. East Coast that would (1) provide the highest overall and peak-time summer capacity factor, (2) use bottom-mounted turbine foundations (depth ≤50 m), (3) connect regional transmissions grids from New England to the Mid-Atlantic, and (4) have a smoothed power output, reduced hourly ramp rates and hours of zero power. Hourly, high-resolution mesoscale weather model data from 2006-2010 were used to approximate wind farm output. The offshore grid was located in the waters from Long Island, New York to the Georges Bank, ≈450 km east. Twelve candidate 500 MW wind farms were located randomly throughout that region. Four wind farms (2000 MW total capacity) were selected for their synergistic meteorological characteristics that reduced offshore grid variability. Sites likely to have sea breezes helped increase the grid capacity factor during peak time in the spring and summer months. Sites far offshore, dominated by powerful synoptic-scale storms, were included for their generally higher but more variable power output. By interconnecting all 4 farms via an offshore grid versus 4 individual interconnections, power was smoothed, the no-power events were reduced from 9% to 4%, and the combined capacity factor was 48% (gross). By interconnecting offshore wind energy farms ≈450 km apart, in regions with offshore wind energy resources driven by both synoptic-scale storms and mesoscale sea breezes, substantial reductions in low/no-power hours and hourly ramp rates can be made. Citation: Dvorak, M.

A Surface Wind Extremes (“Wind Lulls” and “Wind Blows”) Climatology for Central North America and Adjoining Oceans (1979–2012)

“…) occur off the eastern and western coasts of North America, as previous research (Dvorak et al 2010;Sheridan et al 2012) has suggested. This result is due, for the west coast, to the land-sea pressure gradient that creates a persistent marine boundary layer (e.g., Dorman and Winant 1995;Dvorak et al 2010;Jiang et al 2008).…”

“…2b). Two significant synoptic features at work in this region to affect surface wind speeds would be the strength and presence of the warm-season-dominant Bermuda-Azores subtropical high and positioning of the storm track for the cool season (Dvorak et al 2012). As a result, cool-season WBs for region I are likely due to frequent low pressure systems associated with an active and persistent storm track that appears to have varied little since 1979.…”

“…This result is due, for the west coast, to the land-sea pressure gradient that creates a persistent marine boundary layer (e.g., Dorman and Winant 1995;Dvorak et al 2010;Jiang et al 2008). The marine boundary layer is a strong inversion that is typically 500 m above sea level and is caused by the cold ocean current running along the western coast of North America (Dvorak et al 2010). Near the top of the inversion, higher winds become trapped and form a lowlevel jet that diminishes in intensity heading into open water away from the coastline (Jiang et al 2008).…”

“…Off the Atlantic coast, greater wind speeds can likely be attributed to frequent low pressure system passages occurring between the autumn and spring months (Dvorak et al 2012). Furthermore, sea breezes for coastal New England can be enhanced by the anticyclonic flow of the Bermuda-Azores subtropical high, especially in the warm season (Colby 2004).…”

“…Furthermore, sea breezes for coastal New England can be enhanced by the anticyclonic flow of the Bermuda-Azores subtropical high, especially in the warm season (Colby 2004). Coastal locations south of Long Island lack this sea-breeze enhancement as a result of relative positioning with the high pressure system (Dvorak et al 2012). The abrupt drop in wind speeds found going inland from the two coasts is caused by the increased surface roughness (higher friction) of land versus sea that decelerates surface winds (Braun et al 1999).…”