The Rheem ProTerra Electric Hybrid Electric Heat Pump Water Heater. Heat pump technology makes it 4X THE EFFICIENCY of a conventional electric model (of the same or similar capacity). It's so efficient that it can pay for itself in energy cost savings. This model has an estimated energy cost savings of up to $315 per year, or up to $3,150 over 10 years. Plus, it's energy rebate eligible, which means it could be eligible for state, local, or utility rebates. It's smart: with its built-in WiFi and the EcoNet app, you can check hot water availability, track energy usage, and control its modes; choose the efficiency or performance you want. As a Performance Platinum, it comes with a 10-year warranty and a 1-year in-home labor warranty.