Energize Weekly, December 5, 2018
Climate change poses the dual hazard of increasing electricity demand while reducing generating efficiency, as well as producing severe weather that can damage the grid, according to a federal assessment of impacts of climate change.
The Fourth National Climate Assessment, a 1,600-page analysis complied by 13 federal agencies, covers a wide range of potential impacts, from floods to crop failures, which could reduce economic output by 10 percent by the end of the century.
The report, mandated by Congress to be issued every four years, was released by the Trump administration, which rejects climate change, on Nov. 23 during the Thanksgiving holiday weekend. It analyzes impacts on a range of scenarios depicting different greenhouse gas emissions and temperatures.
For the utility industry, the assessment offers a complex suite of challenges. “If greenhouse gas emissions continue unabated,” the analysis said, “rising temperatures are projected to drive up electricity costs and demand.”
Warmer temperatures will lead to a greater demand for cooling power even as energy efficiencies in air conditioning and building design improve. The nationwide climate change-driven electricity demand is projected to increase 3 percent to 9 percent in the higher scenario and 2 percent to 7 percent in the lower scenario.
Increased demand for cooling will likely also increase energy-related emissions of criteria air pollutant.
“To ensure grid reliability, enough generation and storage capacity must be available to meet the highest peak load demand,” the report said. “Rising temperatures could necessitate the construction of up to 25 percent more power plant capacity by 2040, compared to a scenario without a warming climate.”
At the same time a warmer climate is driving demand, it would undermine performance for the bulk of U.S. power plants—coal, natural gas, nuclear, concentrating solar and geothermal—relying on a steady supply of water for cooling. Warmer waters and reduced flows would reduce power plant efficiency with plants having to shut down to comply with discharge temperature regulations to protect aquatic life.
In North America, output from power plants could fall from 7.3 percent to 13.1 percent by 2050, depending upon the scenario.
“A changing climate also threatens hydropower production, especially in western snow-dominated watersheds, where declining mountain snowpack affects river levels,” the assessment said. “For example, severe, extended drought caused California’s hydropower output to decline 59 percent in 2015 compared to the average annual production over the two prior decades.”
The prospect of peak-demand periods created by “longer-lasting extreme heat events” is expected to make blackouts and power disruptions more common.
More severe weather events, in the form of hurricanes, high winds, storm surges and flooding, could severely damage the grid. In Florida, a sea level rise of 3.3 feet would put 11 gigawatts of power generation at risk, the report said.
The report also noted that it cost Con Edison and Public Service Electric and Gas more than $2 billion to repair the damage done by Superstorm Sandy in 2012.
The result of these trends will be higher electricity costs by increasing demand, reducing the efficiency in power generation and delivery, and requiring additional generation. The added cost is estimated at $30 billion a year by mid-century.
By 2040, nationwide, residential and commercial electricity expenditures are projected to increase by 6 percent to 18 percent under a higher scenario and 4 percent to 12 percent under the lowest scenario.
