US Drought Affects Electricity Supply

The severe drought plaguing large areas of the Western USA has reduced lake water levels and rivers are drying up. This poses a challenge to utilities. Hydropower systems are being affected, so they are unable to supply their normal electricity capacity. However this has other unfortunate consequences - fuel-using power plants such as natural gas, coal, and nuclear plants often rely on nearby water to keep their systems cool.

If there is less water nearby or available to be pumped from elsewhere, then those plants cannot deliver enough power, or even, in the worst case scenario have to be shut down.

In Portland, Oregon, temperatures this month have reached 116 degrees Fahrenheit — an all-time high — just one year after the state saw unprecedented wildfires early in the year. New Mexico and California are also suffering from severe drought. Lake Mead, on the Colorado River, has reached its lowest point since the Hoover Dam was built in the 1930s.

When a drought continues for some time, the most serious impact on electricity generation is felt by hydroelectric plants and dams, many of them federally owned and operated. These stations provide key resilience for the electricity grid through their ability to rapidly increase or decrease production to meet demand, sometimes in as little as a few seconds.

People and businesses rely on electricity for refrigeration and cooling in hot weather, but the extremely high temperatures have a dual effect on generation capacity and transmission: last year parts of the grid network had to be shut down in California during the unprecedented wildfire season, causing outages for customers.

A 2012 report from the DOE’s Argonne National Laboratory examining drought’s long-term impacts on power systems in the Southwest stated that during heat wave conditions, transmission lines carry power less efficiently. Gas-fired power plants do not operate optimally, and even solar panels experienced reductions in their generated electricity under those conditions, the study concluded.

Utility professionals need to study the issues produced by the recent heatwave and build in more resiliency into the power production and transmission systems to cope with this new era of increasingly hot weather.