Curtailments of wind generation on the Texas electric grid and occurrences of wind-related negative real-time electricity prices have both declined since 2011.
The U.S. Energy Information Administration (EIA) says that due to more than 3,500 miles of transmission lines built -- mostly as a result of Texas’ Competitive Renewable Energy Zones (CREZ) – the negative electricity prices and wind curtailments have dropped because the transmission expansions have allowed wind power to flow to higher demand areas.
More than 7,000-MW of utility-scale wind came online in Texas between 2006 and 2009, which led to transmission congestion as the wind from projects in the western and northern areas of the state were sometimes unable to reach the population centers in the eastern regions of the state. Excess wind generation was curtailed by the grid operator, the Electric Reliability Council of Texas (ERCOT) in order to keep the network operating within its physical limits, the report said.
In addition to curtailments, the imbalances caused real-time wholesale electricity prices at the West Hub in ERCOT to drop and even go negative during periods of substantial wind generation. Negative prices occur when generators are willing to pay for the opportunity to continue generating electricity.
To view graphs with the full report, click here