Giant Water heaters: energy use and running cost
The average model uses 1,080 kWh a year, which costs $227 a year at 21.0¢/kWh.
Most efficient models
| Model | kWh/year | Cost/year |
|---|---|---|
| Giant GTHPCO-45 1**+GTXST-50LBTTP 1* | 915 | $192 |
| Giant GHPCO-45 1**+GXST-50T 1** | 923 | $194 |
| Giant GHPCO-45 1**+GXST-50TTTP 1** | 923 | $194 |
| Giant GTHPCO-45 1**+GTXST-50S 1* | 923 | $194 |
| Giant GTHPCO-45 1**+GTXST-50STTP 1* | 923 | $194 |
| Giant GTHPCO-45 1**+GTXST-50T 1** | 923 | $194 |
| Giant GTHPCO-45 1**+GTXST-50TTTP 1** | 923 | $194 |
| Giant GTHPCO-45 1**+GTXST-80 1** | 1,306 | $274 |
| Giant GTHPCO-45 1**+GTXST-80TTP 1** | 1,306 | $274 |
| Giant GTHPCO-45 1**+GTXST-66 1** | 1,341 | $282 |
| Giant GTHPCO-45 1**+GTXST-66TTP 1** | 1,341 | $282 |
- Refrigerators
- Freezers
- Washing machines
- Dishwashers
- Tumble dryers
- Room air conditioners
- Dehumidifiers
- Electric cooktops and ranges
- Televisions
- Computers
- Air purifiers
Source: ENERGY STAR (U.S. EPA) · 21.0¢/kWh (August 2026) · Methodology