At 3:00 AM on July 10, 2015, wind turbines in Denmark generated a record setting 140% of national electricity demand.

Key Details

• Lawrence Berkley National Laboratory estimates that wind generation accounted for nearly 40% of Denmark’s electricity production in 2014 (see chart)
• The incident resulted from a combination of unusually high winds and low electricity demand, which occurs during the middle of the night
• Excess electricity was exported to Norway, which could store the energy in hydropower systems, as well as Germany and Sweden
• By comparison, instantaneous wind penetration records in the United States include:
  • 61.1% of demand for Xcel Energy Colorado on November 1, 2014
  • 42.7% of demand for Bonneville Power Administration on April 11, 2015
  • 40.6% of demand for ERCOT on March 29, 2015
• According to European Wind Energy Association, Denmark had 4,485 MW of cumulative installed wind capacity at the end of 2014

                              Approximate Annual Wind Energy Production in Select Countries

Implications

Wind power is a significant part of the overall electricity supply in Denmark. The variable nature of wind can cause wide swings in production. At high penetrations, this can have a meaningful impact on the overall supply/demand balance. Robust grid infrastructure and dynamic energy market are required to accommodate high penetrations of variable renewable resources. Otherwise, grid operators must curtail renewable resources to maintain a balance between electric generation and load demand.

More Information

Guardian: Wind Power Generates 140% of Denmark’s Electricity Demand

European Wind Energy Association: Wind in Power – 2014 European Statistics

American Wind Energy Association: Wind Energy Keeps Breaking Records – In Denmark and Here at Home

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