The wholesale price of electricity will rise in the Northwest this summer as drought-stricken California buys energy from neighboring states to offset a nearly 50% reduction in hydropower, the U.S. Energy Information Administration projects in a new report.

California can cover about half of the 6 million megawatt-hour cut in hydropower by ramping up natural gas plants but will need to purchase electricity on Western power markets to make up the rest, according to the EIA.

California’s demand for electricity will in turn put pressure on power supplies elsewhere. The EIA estimates the Golden State’s drought will push up peak-demand wholesale prices by 5% in Idaho, Oregon and Washington to an average of $59 per megawatt-hour.

“California has a diverse electricity fuel mix and is highly interconnected with the regional electric grid, but our study shows that a significant decrease in hydropower generation this summer could lead to higher electricity prices, among other effects,” EIA Administrator Joe DeCarolis said in a statement.

The EIA’s report supplemented a forecast on retail electricity prices. Assuming a cooler summer than last year, the EIA projected customers will pay about 4% more in the West than in 2021, though rates will vary widely by utility.

Wholesale prices are more volatile than retail rates, reflecting the ever-changing demand for and supply of energy, especially on the hottest summer days, according to the EIA.

Drought blankets California. About 60% of the state is in an “extreme” or “exceptional” drought, the two worst categories, according to the U.S. Drought Monitor.

California’s snowpack was 54% of normal on April 1. With little snow to melt into already lower reservoirs, the state will generate 48% less hydroelectricity between June 1 and Sept. 30 than in a non-drought year, the EIA forecasts.

Normally, hydroelectricity meets about 15% of the state’s summer energy needs. This year, it will provide 8%, the EIA projects.

To partially fill the gap, California will use more electricity generated by natural gas. The EIA estimated carbon emissions from the energy sector will increase by 978,000 tons, or 6%.

Even then, the state will need to import another 2.9 million megawatts-hours. California already buys one-third of its power from out-of-state sources.

The EIA projected California will generate about as much hydropower this summer as it did in 2015, another poor water year.

The state, however, has less ability than it did seven years ago to ramp up during peak demands to offset the lost of hydropower, according to the EIA.

California has added solar power and battery storage since 2015, but 58% of the state’s natural gas-fired power capacity was shut down.

The EIA said droughts in Arizona and Nevada also could push up the cost of electricity. Prices could be held down if retail customers adjust and use less electricity during peak times, according to the report.