You don't know what you've got until it's gone, and the total eclipse is a stark reminder of that saying when it comes to the key role solar energy currently plays in the US.
More than 31 million people (nearly 10 percent of the U.S. population) live in an area that will experience the total solar eclipse today. Millions more live near dirty power plants that could be tapped to offset lost solar energy.
Grid administrators have had to find backup power sources to cope with the eclipse. It shows us how far the nation has come in cleaning up its power grid and what we still urgently need to complete that task.
All 50 states will experience some degree of disruption
All 50 states will experience some degree of disruption to solar power generation during the eclipse, according to the National Renewable Energy Laboratory (NREL). It predicts a whopping 93 percent reduction in peak power from solar panels within the grid in Texas, where the solar eclipse will first cross into the U.S. before tracing a diagonal path across the nation toward Maine. The maximum power reduction is expected to reach 71 percent on the eastern grid and 45 percent on the western grid.
The eclipse only reaches “totality”, when the Sun is completely blocked by the Moon, for several minutes in each place. But a partial eclipse can persist for several hours. While solar generation falls, electricity demand is expected to increase. Homes and businesses with photovoltaic panels will not be able to rely as much on their own solar systems: they will need to rely more on the grid.
That type of mismatch between supply and demand is what can cause outages. Those responsible for the network have had a lot of time to prepare for this eclipse, so experts do not expect any blackouts. Hydropower and gas are supposed to make up most of the solar energy shortfall. NREL expects gas to cover about 30 percent of the loss in utility-scale solar generation.
In short: more gasoline, more pollution. Nationally, that's not good for U.S. climate goals, which aim to cut greenhouse gas emissions by about half by 2030 compared to 2005 levels. When it comes to soot-forming pollutants and smog, the effects are most concentrated in communities bordering fossil fuel power plants.
About 32 million people in the United States live within three miles of a peaking plant, a facility that typically runs on gas and is turned on during “spikes” of energy demand like the one expected to trigger the solar eclipse. . The peaks are some of the The dirtiest power plants in the country, and most of them are located in communities of color and low-income neighborhoods..
The last time a total eclipse occurred in the US was in 2017, Gas replaced most of the lost solar energy.. But many things have changed since then. For starters, the path to totality this time is significantly wider, meaning a much larger area is affected. Furthermore, solar energy has become the cheapest source of electricity in history. America has much more now, around 2.5 times more solar generation capacity than in 2017.
While solar panels don't pump out greenhouse gases or worsen air quality for nearby residents like fossil fuel power plants do, solar power presents its own challenges. That is, it disappears when the sun does not shine. Of course, this isn't just a problem during a solar eclipse.
Fortunately, the United States has made some progress on that problem as well. Battery storage in the US has grown from 0.6 GW during the last solar eclipse to 15.4 GW today. Still, much more energy storage is needed. The eclipse is forecast to completely or partially block sunlight from large-scale solar farms with a combined capacity of 91.3 GW, according to the Energy Information Management. To get a sense of scale, that's almost all of the country's utility-scale solar capacity (although the US has about 139 GW of capacity). by including small-scale solar energy).
As an alternative to gas plants, pumped hydroelectric energy storage will offset 42 percent of the solar energy shortfall during the eclipse. That involves pumping water from a lower elevation to a higher elevation and then letting it flow through a turbine to generate electricity. He system It basically works like a giant battery, and without it, the current loss of solar energy would likely have had even more consequences for air quality and climate.
Increase the capacity to generate and Storing renewable energy so that there is always a reliable supply is one of the biggest challenges facing electricity grids today. The solar eclipse is just one test of how prepared the United States is to meet this challenge. It also shows how the only other alternative—continuing to rely on dirty energy sources—comes at an unfair cost to many Americans.
