Sunamp Ltd. continues to seek financing to fund development of its commercial-scale heat battery, the SunampCube. The device is designed to store energy generated by wind, solar and other renewable sources, as well as harvest excess heat generated by waste-treatment facilities.
The Scottish company is in negotiations to use the technology to transport waste heat by barge from the Avonmouth waste processing facility to Bristol for use in the district heating system under construction there. The batteries would be stored in 16 shipping container units, each holding 2 MWh of heat.
"We have built and tested a number of cells that will be used to build the full-scale device," says CEO Andrew Bissell. "Each one is a single cell storing 45-50 kWh."
What type of phase change material is being used?
"It's a salt hydrate ... our own tweak on sodium acetate trihydrate with both a nucleator and a stability enhancer," Bissell says. "58C melt and freeze points - almost no subcooling or hysteresis. And very cycle stable. We have cycled a test heat battery over 26,000 times with no loss of capacity or degradation in any metric."
Bissell says the company is working on financing for the project's next phase.