Lenovo 21RK: $2 a year to run
This model (Computers) uses 12 kWh of electricity a year, which costs about $2 a year and $24 over 10 years at 21.0¢/kWh.
Energy use
12 kWh
per year
Running cost per year
$2
21.0¢/kWh
Running cost over 10 years
$24
Efficiency rank
454 / 1,748
Product details
| Type | Notebook |
|---|---|
| Battery capacity (Wh) | 54.7 |
| Available since | May 8, 2025 |
Compared with the average model (Computers), this one saves about $3 a year.
More efficient alternatives
| Model | kWh/year | Cost/year |
|---|---|---|
| Acer SFB14-52M | 12 | $2 |
| Acer CB315-8H | 12 | $2 |
| Acer SFG14-75 | 12 | $2 |
| DELL Dell 15 D15266 | 12 | $2 |
| DELL Dell Pro Essential 15 PV15266 | 12 | $2 |
| dynabook WLL10* | 12 | $2 |
| dynabook PNM35U | 12 | $2 |
| Lenovo IdeaPad Slim 5 14IRH10R | 12 | $2 |
- Refrigerators
- Freezers
- Washing machines
- Dishwashers
- Tumble dryers
- Room air conditioners
- Dehumidifiers
- Water heaters
- Electric cooktops and ranges
- Televisions
- Air purifiers
Source: ENERGY STAR (U.S. EPA) · 21.0¢/kWh (August 2026) · Methodology