California, expecting the lowest hydroelectric generation in a decade, will lean on solar and natural gas-fired power to get through spring and summer months when demand typically peaks.
Hydropower capacity will probably drop to the “extreme” low of 4,628 megawatts during this summer’s peak season, down 40 percent from 2014 levels, the state grid manager California Independent System Operator Inc. said on Tuesday. The ISO is scheduled to release its final summer forecasts within the next couple of weeks. The 10-year average for hydro supply is 8,180 megawatts.
California is entering its fourth year of an unprecedented drought that has dried up hydropower supplies, fallowed farmland and led Governor Jerry Brown on April 1 to order a 25 percent mandatory reduction in water consumption in towns and cities. A state snowpack measurement on April 1 showed water content was 5 percent of normal for this time of year, the driest in recorded history, according to the state Department of Water Resources.
“The hydro system has been significantly de-rated,” California ISO chief executive officer Steve Berberich said by phone on Tuesday from Folsom, California. “Year over year, do I think there will be more gas that runs potentially this year than last? Potentially. But I think predominantly it’ll be solar.”
The grid operator is preparing its annual summer power forecasts, in which it projects supply and demand under both “normal” and “extreme” scenarios during the season when electricity consumption typically peaks. An initial assessment in late March projected that hydropower capacity would fall 3.8 percent to 7,371 megawatts in 2015 from 7,666 last year. One megawatt-hour is enough to power 1,000 homes for an hour.
“I think we’re going to see the extreme case,” Berberich said.
California’s total generating capacity rose 2,135 megawatts from a year earlier. Of that, 2,066 megawatts was solar, the California ISO’s initial assessment shows. Transmission upgrades in San Diego and Orange County are also starting to come online, the grid operator said.
California accounted for 10 percent to 20 percent of hydropower in the Western U.S. census region in the previous five years, Michelle Bowman, an analyst with the Energy Information Administration in Washington, said in an April 13 e-mail. Initial water supply forecasts for the Pacific Northwest show total power produced from dams may slip 2 percent this year.
Water flows so far this year at The Dalles on the Columbia River in Oregon, a benchmark for hydrogeneration in the Pacific Northwest, “started off so much higher than 2014” and flows into the Columbia River “should be relatively healthy” because of snowpack in the Canadian Rockies, Bowman said.
The Bonneville Power Authority, which manages output from government dams and the grid in the Northwest, is seeing snowpack at 95 percent of the average in the region because of precipitation at higher elevations, offsetting low snowfall in Oregon, Mike Hanson, a spokesman for the agency, said by phone on April 10.
The California-Oregon Intertie line, known as COI, can export 4,800 megawatts to California from the Pacific Northwest.
“We can lean on COI to the extent that we have capacity,” Berberich said. “But it all depends on how much generation is on the other side. There’s a general shortage of hydro across the West because of a lower snowpack. In California, it’s largely going to be replaced by renewables. If you take everything together, I think we’re going to be well-positioned, and I don’t expect a whole lot of upward pressure on pricing.”
Above-normal temperatures in the West accelerated the thaw of snow, a natural form of energy storage, so the hydrogeneration season is unlikely “to show up in force this summer,” Rick Margolin, senior natural gas analyst for Louisville-based Genscape Inc., said in a March 25 web conference.
“The hydro season really only runs through the end of July; beyond that we basically start getting back into normal conditions,” he said. “By August, September, October we do not expect any incremental burn from the hydro conditions in the Pacific Northwest.”