Sandia National Laboratories and CSolPower are researching the use of landscaping gravel as a thermal energy storage medium. New Mexico-based CSolPower LLC is partnering with Sandia National Laboratories to research and develop the use of landscape gravel as a thermal energy storage medium for intermittent sources of generation like solar and wind.
Loading sand and gravel into the cable car is facilitated through an underground gas station, where valves release the sand and gravel stored in the upper and lower storage locations. The energy storage capacity of the MGES system is constrained by the terrain, and the larger the height difference, the more energy it can store.
TES also has another key advantage: the cost. Ma has calculated sand is the cheapest option for energy storage when compared to four rival technologies, including compressed air energy storage (CAES), pumped hydropower, and two types of batteries. CAES and pumped hydropower can only store energy for tens of hours.
These forms include Tower Gravity Energy Storage (TGES), Mountain Gravity Energy Storage (MGES), Advanced Rail Energy Storage (ARES), and Shaft Gravity Energy Storage (SGES). The advantages and disadvantages of each technology are analyzed to provide insights for the development of gravity energy storage.
There is currently no viable technology in the market for offering affordable long-term energy storage with a low generation capacity, especially lower than 20 MW. This paper argues that this gap can be filled with a novel solution called Mountain Gravity Energy Storage (MGES).
This would impede the access to the lower storage site. Steep mines are appropriate due to the high changes in altitude, which would improve the viability of the project. The access to the upper storage site in the mountain might be difficult and there might not be available location to store the sand or gravel.