Rheem’s Prestige Series hybrid electric heat pump water heater achieves an Energy Factor of 2.45. It costs less than $18 a month to operate and homeowners can save $370 annually with this Energy Star-qualified unit, compared to a standard 50-gal. electric model (0.90 EF and 4,879 kWh). This product also includes a full-color, backlit touch-screen control that displays easy-to-read homeowner service alerts, as well as diagnostic information for contractors and installers.