The energy saving Tempra Plus tankless electric water heaters, Accelera heat pump water heaters and solar thermal renewable energy systems all make up a composite of main water heating product offerings. Tempra Plus tankless electric features advanced flow control to automatically keep output temperature constant and provide an unlimited stream of hot water. Units are also ideal backups for solar thermal systems. Accelera 300 Heat Pump water heaters have large capacity (80 gal), low power input 500 W in heat pump mode (2.2 kW incl. back-up element) and low power consumption (1391 kWh/year), translating to $167/year based on 12 cents/kWh.