Scientists are actively exploring innovative methods for sustainable storage of renewable energy, such as solar, wind, and hydropower. A recent collaboration between engineers from Sandia National Laboratories and CSolPower LLC aims to develop an affordable way to store renewable energy.
The project involves integrating wind and solar energy into an electrically charged thermal energy storage system that uses rocks as a medium.
This cost-effective solution has the potential to be used in various applications, providing power during high-demand periods or when renewable sources are not available. The engineers have successfully created a compact test rig to evaluate the performance of the rock bed at the National Solar Thermal Test Facility. The facility is located in Albuquerque, New Mexico.
Walter Gerstle, one of the co-founders of CSolPower, told Interesting Engineering that thermal energy storage in rocks offers several advantages. Because rocks are found everywhere, the technique be implemented quickly and economically without extensive permitting.
The focus of CSolPower’s technology is on long-duration energy storage. Long-duration storage refers to storing energy for time frames ranging from hours to months.
During testing, the system maintained a temperature of over 500 degrees Celsius (900 degrees Fahrenheit) for up to 20 hours using heated air. The system behaved as the scientists had anticipated.
Gerstle further explained that surplus electricity generated during the day can be stored as heat and used to warm buildings at night.
The testing phase for the technology prototype will continue until the summer of 2024.
Scientists outside of the United States are also recognizing the potential of rocks to store vast quantities of renewable energy. A team of Tanzanian scientists published a study earlier this year that found that Craton soapstone is the ideal thermal energy storage rock. Even at temperatures of over 980 degrees Celsius (1,796 Fahrenheit), the Craton soapstone did not crack.
Image Source: Sandia National Laboratories