Energy Use in ERCOT Region Grows 2.2 Percent in 2015, Wind Now Delivers 11.7% of Generation

Record summer demand drives energy use to nearly 7.5 million MWh more than 2014

From ERCOT – (Austin, Texas)  A record-breaking summer, which brought a new all-time peak demand record approaching 70,000 megawatts (MW), contributed to an increase in electricity use in the Electric Reliability Council of Texas (ERCOT) region in 2015.

The 2015 Demand and Energy Report, released today by ERCOT, showed the system ended the year at 347,522,948 megawatt-hours (MWh), an increase of 7,489,595 MWh, or 2.2 percent, over the 340,033,353 MWh consumed in the region in 2014.


Contributing to 2015’s growth was a series of new peak demand records, the first since the region’s hottest summer on record in 2011. By summer’s end, the system had new records for monthly energy use, July peak demand, weekend peak demand and all-time peak demand.

On Aug. 10, the ERCOT region set a new all-time demand record of 69,877 MW, marking the first-time in ERCOT’s history demand topped 69,000 MW. Ultimately, three of the top five all-time peak demand records occurred in 2015:

  • 69,877 MW ‒ August 10, 2015
  • 68,912 MW ‒ August 6, 2015
  • 68,459 MW ‒ August 5, 2015
  • 68,305 MW ‒ August 3, 2011
  • 67,929 MW ‒ August 2, 2011

Demand in July hit four consecutive new monthly records (July 27, 28, 29 and 30), ultimately peaking at 67,650 MW on July 30. When the system hit 67,590 MW on July 29, it was the first time since 2011 that system demand had exceeded 67,000 MW.

Also succumbing to the August heat was the previous weekend record set in 2011, which increased from 65,159 MW, set on Aug. 28, 2011, to 66,587 MW on Aug. 8, 2015.

As a reminder, one MW is enough power to serve about 200 homes during summer peak demand and about 500 homes during milder weather conditions.

Wind shifts system fuel mix
Natural gas, at 48.3 percent, continues to be the dominant fuel used to generate electricity in the ERCOT region, followed by coal at 28.1 percent. In 2015, wind moved from fourth to third, at 11.7 percent, providing about 40.8 million MWh during the year. This surpassed nuclear power, which increased slightly from 2014 but, at 39.4 million MWh, provided about 11.3 percent of the total energy used.


The Electric Reliability Council of Texas (ERCOT) manages the flow of electric power to nearly 24 million Texas customers, representing about 90 percent of the state’s electric load. As the independent system operator for the region, ERCOT schedules power on an electric grid that connects more than 46,500 miles of transmission lines and 550 generation units. ERCOT also performs financial settlement for the competitive wholesale bulk-power market and administers retail switching for more than 7 million premises in competitive choice areas. ERCOT is a membership-based 501(c)(4) nonprofit corporation, governed by a board of directors and subject to oversight by the Public Utility Commission of Texas and the Texas Legislature.