Roof de-icing cable vs. snow melting mat: running cost
A snow melting mat is cheaper to run: about $10 a year versus $79 for a roof de-icing cable at typical use and 17.99¢/kWh, a $69 difference.
| Roof de-icing cable | Snow melting mat | |
|---|---|---|
| Typical watts | 500 W | 200 W |
| Watt range | 100–1,500 W | 40–1,000 W |
| Typical use | 12 hours a day for 4 months a year | 8 hours a day, 2 days a week for 4 months a year |
| Energy per year | 438 kWh | 56 kWh |
| Cost per hour | 5.4¢ | 3.6¢ |
| Cost per day | 65¢ | 8.2¢ |
| Cost per month | $19.71 | $2.50 |
| Cost per year | $79 | $10 |
| Per year in Hawaii (43.51¢) | $191 | $24 |
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What drives the difference
- Roof de-icing cable: Roof and gutter de-icing cables draw about 5 W per foot. Many people leave them on all winter, which makes them a surprisingly large load.
- Snow melting mat: Portable heated mats draw about 20-35 W per square foot and run at full power while on. Defaults assume they are turned on for snow and ice events, about 2 days a week in winter.
Ways to cut either cost
Runs mats only when snow or ice is actually present.
See options on AmazonTreats steps for occasional storms with no electricity.
See options on AmazonPrevents the cable running in weather where it does nothing useful.
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Frequently asked questions
Which costs more to run, a roof de-icing cable or a snow melting mat?
At typical use and the U.S. average rate (17.99¢/kWh), a roof de-icing cable costs about $79 a year versus $10 for a snow melting mat. That's $69 more, or 7.9× as much.
How many watts do roof de-icing cable and snow melting mat use?
A roof de-icing cable typically draws 500 W (range 100–1,500 W). A snow melting mat draws 200 W (range 40–1,000 W). Watts alone don't decide cost. Hours of use, cycling and standby matter just as much.
Rates: EIA, 12 months ending 2026-07. Methodology.