“Alaska needs unique storage technology due to seasonal variations in solar/wind availability. Cache’s technology allows Alaskans to tap into clean, affordable energy consistently throughout the year,” Dwivedi says.
For now, the pilot project at the Halliburton yard is powered by an onsite generator, for testing purposes. Dwivedi says the heat exchangers could draw electricity from any source, and the discharged hot air could be used directly for district heating or any type of waste heat generator.
Because of the chemical reaction, Cache Energy boasts of a higher capacity per unit mass than other heat storage methods, such as raising the temperature of a large mass of molten salt or ceramic. The company figures its pellets hold 500 watt-hours per kilogram, compared to the best-performing sand battery at 140 Wh/kg.
The pilot project involves a unit that could store energy for approximately fifty households, Dwivedi estimates. As the system scales up, the silo diameter grows. Stored quicklime could also be transported wherever the material is needed most.
Cache Energy has demonstrated the system over a year-long cycle. The pilot project is meant to test the reliability of the equipment under Alaska conditions. Dwivedi adds that it’s also testing the ease of use; the company deliberately hired arts majors, not engineers, to prove that the system could be deployed in communities without highly skilled operators.
