(NASA’s global gravity anomaly animation over land from GRACE satellites.)
Hydropower operators may soon have a new long-term forecasting tool.
Like other forms of renewable energy, hydroelectric plants have to work around a certain amount of variance in the amount of power they put out. When the flow of water increases they put out more power. When the flow of water decreases they put out less power.
Now, researchers at the University of California, Irvine may have found a way to identify which rivers are most likely to flood up to a year in advance. Water collecting on Earth – whether surface water, groundwater, soil moisture, ice, or snow – very slightly alters the Earth’s gravitational field. So the researchers turned to NASA satellites orbiting the Earth, and measured how these gravitational bumps affect their orbit. From that, they can identify areas where water has collected and may soon be released.
Unlike other methods, this could allow the researchers to predict floods up to a year in advance. (Although this method alone can’t account for floods or other effects from rain or other weather events.)
For now, the researchers are focused on identifying flood risks, but it’s easy to imagine hydropower operators using the same techniques to improve their output forecasts.
In places like California, where the waterways are fed by melting snowpack, the amount of precipitation in the fall and winter lets us know what to expect from water flows in the spring and summer. It’s how we’ve predicted difficulties in the past. Measuring gravitational fields can give us another tool in our forecasting toolbox.