Two new studies led by a North Carolina State University researcher provide a glimpse into what electricity consumers on the West Coast might face in two future scenarios: one in which excessive heat due to climate change puts a strain on power supplies, and another in which the grid shifts to renewable energy while the climate follows historical patterns. They discovered that power costs and reliability are still subject to extreme weather in both instances.
“The impacts of climate change and extreme weather events on the grid, mostly in the form of drought and heat waves, are going to get worse under climate change,” said Jordan Kern, assistant professor of forestry and environment resources at NC State. “Even as the West Coast grid moves away from fossil fuels toward wind and solar, these extreme weather events will still impact system reliability and the price of power.”
The two assessments, which were published in the journal Earth’s Future, forecast future electricity supply and demand under different scenarios. In the first study, researchers utilized computer models to evaluate the effects of climate change on California’s and the Pacific Northwest’s current power grids.
They looked examined the grid’s price and reliability under 11 various climate scenarios from 2030 to 2060, using a variety of scientific models to see how the climate would change under a “worst-case scenario” of fossil fuel emissions and a less severe scenario.
“The worst-case scenario is worth looking at even if there’s some evidence that the world is going to reduce fossil fuel emissions enough to avoid it,” Kern said.
The researchers discovered a higher likelihood of power outages in the summer and early fall, owing to excessive heat in California, which generates a surge in demand for electricity as people try to cool their houses. They predicted shortfalls in all but one scenario, in which climate change impaired electricity generation in both regions at the same time.
They did say, though, that these power outages would be unusual. The worst-case scenario included 72 hours of West Coast-wide power outages spread out over 31 years.
“As it gets hotter and hotter and hotter, and demand for electricity gets higher, we expect the grid to fail,” Kern said. “Those extreme heat events are going to become much more severe.”
The impacts of climate change and extreme weather events on the grid, mostly in the form of drought and heat waves, are going to get worse under climate change. Even as the West Coast grid moves away from fossil fuels toward wind and solar, these extreme weather events will still impact system reliability and the price of power.Jordan Kern
The extreme heat would affect the price and supply of power in the Pacific Northwest in California. The regions have traditionally shared power.
“If, and that’s a big ‘if,’ historic exchanges of electricity continue, and California has a high demand for electricity because of heat, it could cause the Pacific Northwest to run out of electricity, as they won’t be able to meet their own demand,” Kern said.
They also discovered that climate change could have a direct influence on the Pacific Northwest by restricting hydropower supply, which is electricity generated by water. Because snow acts as a storage medium, variations in the amount of snow or the time of snowmelt affect the amount of power accessible in the summer.
Climate change would have the greatest impact on the Pacific Northwest in the late summer or early fall, when the grid is already stressed. Even little reductions in streamflow induced by climate change in September, along with increased summer power consumption, would be enough to produce additional power shortages in the Pacific Northwest.
They did, however, predict that West Coast-wide shortfalls owing to climate impacts on the Pacific Northwest alone would be uncommon. In addition to reliability concerns, the researchers discovered that climate change will raise the cost of electricity.
They projected more hours in which the wholesale price of electricity hits the cap of $1,000 megawatts per hour in California, especially in late summer, in the worst-case scenario when climate change effects power supply and demand in both California and the Pacific Northwest. Climate change in California would have a huge impact on Pacific Northwest prices.
“When prices go up to $1,000 per megawatt hour, that’s the grid ringing the alarm bell,” Kern said. “They’re making electricity so expensive partly in order to incentivize people to consume less.”
In a separate study, researchers looked at the cost of electricity in 2050 with more renewable energy sources added to the system, assuming that natural gas power plants would still be available as backup.
They analyzed five scenarios for each market: two that adjusted the mix of solar and wind by cost; one with additional batteries installed to store electricity; one in which many people are adopting electric vehicles; and the status quo trend.
They looked examined the cost of electricity in these various systems across 100 years of typical and extreme weather events that may occur under historic climate conditions without further warming.
“With the West Coast grid now, we know certain things about how it will perform because it relies so much on hydropower that a dry year is a bad and a wet year is good,” Kern said. “What we wanted to know is: as you decarbonize the grid out West, adding electric vehicles, batteries, solar and wind, does that shift at all?”
Even with renewables, they discovered that extreme heat and drought would drive price extremes, with “good” years having the lowest prices due to mild temperatures and high streamflow, and “bad” years having the highest prices due to extreme heat or drought.
“When you think about the very worst years, those conditions will still be driven by what drives those events today: lack of water or a heat wave in the middle of the summer,” Kern said. “Adding renewable energy does not change the very worst or best year, but it kind of shifts things around in the middle.”
The future scenario with more wind energy has the lowest prices in California, followed by solar. The scenarios with the most wind and solar power had the lowest pricing in the Pacific Northwest. Shortages in supply would be more common along the line with the highest demand for electric vehicles.
“As the grid uses more wind and solar, the price goes down because it’s less expensive, and it pushes out natural gas,” Kern said. “The exception is that when you have high demand for power from electric vehicles, demand gets so high, it breaks the system. It’s pretty rare in our models, but it happens when there isn’t much water and there’s a heat wave.”
Kern called the reductions in greenhouse gas emissions expected under the five scenarios “conservative,” noting that their models show up to 50% de-carbonization by 2050, although most West Coast governments have set objectives to make more significant adjustments sooner.
“Our key finding was that as the grid decarbonizes, you are still going to be left with that vulnerability to water and heat,” Kern said. “This is a system that can’t run away from that.”
The study, “The Effects of Climate Change on Interregional Electricity Market Dynamics on the U.S. West Coast,” was published online in Earth’s Future on Dec. 7, 2021. In addition to Kern, the other authors were Joy Hill, David E. Rupp, Nathalie Voisin, and Gregory Characklis. The study was supported by the National Science Foundation INFEWS program under awards 1639268 T2 and 170082 T1.
On Dec. 28, 2022, the second study, titled “Technology pathways could help drive the US West Coast grid’s exposure to hydrometerological uncertainty,” was published online in Earth’s Future. Other authors include Jacob Wessel, Nathalie Voisin, Konstantinos Oikonomou, and Jannik Haas, in addition to Kern.
The study was supported by the National Science Foundation INFEWS program award 1639268 and the US Department of Energy Office of Science as part of research in the MultiSector Dynamics, Earth and Environmental System Modeling Program.