The US Energy Department has released a report which confirms that adding even limited electricity transmission can significantly reduce the costs of expanding wind energy to supply 35% of US electricity by 2050. The report, titled Reducing Wind Curtailment through Transmission Expansion in a Wind Vision Future and authored by the National Renewable Energy Laboratory (NREL), affirms the findings of the Energy Department’s 2015 Wind Vision.
For the study, NREL simulated operation of the electric power grid under a scenario where 35% of electricity comes from wind in the year 2050 using PLEXOS, an integrated modelling tool. The study focuses on the Western Interconnection grid, which includes 11 states, two Canadian provinces, and parts of northern Mexico where the US grid crosses the border. The study includes a baseline scenario assuming no significant transmission expansion across the western grid, as well as three scenarios with varying levels of transmission buildout. In the baseline scenario with no transmission expansion, substantial renewable energy curtailment—times in which wind farm operators are told not to produce energy due to limited capacity on the grid—could become a major issue. In this scenario, about 15.5% of wind energy capacity goes unused with consequent increases in system costs as a result of idled wind generation. The study also finds that if just four currently proposed transmission projects are built, wind curtailment can be reduced by about half, cutting lost generating potential to 7.8%. If the nation deploys additional transmission beyond those four proposed projects, wind curtailment can be reduced even further—allowing full use of wind energy, reducing generation costs, and unleashing additional economic and societal benefits.
