MIT-WPU researchers develop solar thermal battery for hot water supply after sunset - pv magazine Global

The prototype stores solar heat using a phase-change material, reducing dependence on electricity and conventional fuels for water heating. It can store around 1.5 kWh to 2 kWh of thermal energy and maintain water temperatures between 50 C and 60 C for up to 14 hours after charging.

Raccontata dapv-magazine.com