Pierre Delforge, from the Natural Resources Defense Council, discusses the benefits that solar water heating can provide to California homes and offices. In the development of the 2019 Building Energy Efficiency Standards NRDC proposes a “menu of options…designed to give builders and new home buyers flexibility while guaranteeing energy, carbon, and bill savings.”
NRDC proposes a menu of three options:
1) use super-efficient heat pump water heater (HPWH) powered by solar electricity,
2) use a solar thermal water heater (a collector on the roof that heats water directly from the sun and then stores it in a tank inside the building), combined with a backup gas or electric water heater, and
3) use a standard gas tankless water heater but saving energy and emissions through more efficient walls, attics, and windows instead.