Intermittency, Storage, Land
The good news is that solar is available right now. Every working solar panel counts in the global effort to cut greenhouse gas emissions. But there’s still a lot of skepticism. Here are three common objections to solar and wind power: intermittency of the sun and wind, storage batteries, and physical space needed for wind and solar farms.
Obviously adequate storage of energy is part of the answer to this issue and work is being done now to improve that technology. A report published in 2021 analyzes 39 years of hourly solar and wind data (1980-2018) and shows us how clean energy generation and storage can meet electricity demand in 42 nations.
Many energy storage batteries require rare earth metals like cobalt and lithium that bring their own issues. But battery development is moving ahead rapidly. For instance, batteries that use sodium instead of lithium and don’t need nickel or cobalt are currently being manufactured in China on a large scale. Iron-air flow batteries promise to be ten times cheaper than lithium-ion batteries and are scheduled for mass production in 2024. New battery chemistries are eliminating the use of cobalt and lithium, to the extent it will still be needed, can be extracted from seawater or clay rather than mined.
We now know a lot more about how to effectively store electricity locally, regionally, and even nationally. Plus, millions of electric vehicles plugged into the grid can help the grid charge once each vehicle is fully charged. In addition, peak-load combustion turbines fueled by green hydrogen provide yet another way to achieve a 100 percent renewable grid. In California, energy storage is already replacing large-scale gas peaking plants.
The United States land area is 3.8 million square miles. According to a report by the National Renewable Energy Lab (NREL), it would take roughly 19,700 square miles for solar and wind to generate 60-75 percent of the nation’s zero-carbon electricity by 2035. That’s about the same amount of space occupied by railroads. Researchers at Stanford project that all U.S. energy needs could be met with a commitment of around 38,000 square miles (or 0.65% of total land area) for wind, water, and solar energy.
Better yet, solar can share the land with other uses. Rooftops, walls, and windows can be solar sites, as can solar awnings over parking lots, along or above highway and agricultural pasture and crops. The sun is immense. We are just beginning to tap its energy.