Reservoir wants its heat-pump water heaters to double as a distributed thermal battery fleet

Reservoir, which has raised an $8M seed, says its connected heat-pump water heaters can relieve grid strain at the neighborhood level. The company intends to aggregate installed units into utility demand response programs, absorbing renewable energy when abundant and curtailing draw when the grid is stressed. Roughly 100 units are installed; 1,000 are targeted by end of 2027.