The short answer
Prioritize the furnace blower, well or sump pump, refrigerator and phones; keep generators outdoors with clear exhaust paths despite snow drifts; and keep batteries warm enough to deliver their rated capacity.
Heat and water
- A gas or oil furnace needs electricity for its blower and controls — a few hundred watts on average, plus starting surge.
- A well pump can be the largest motor in the house; check its nameplate and starting watts before choosing a unit.
- A sump pump matters in a thaw after heavy snow.
See the pages for furnace blowers, well pumps and sump pumps.
Generators in snow
- Keep the generator outdoors on a dry, level base above snow depth; keep exhaust paths clear of drifts.
- Keep the exhaust pointed away from the house and clear of snow at all times; do not box it in.
- Check the maker's guidance on cold starting and oil.
SafetySnow and drifts can redirect exhaust toward the house. Carbon monoxide alarms on every level are not optional.
Batteries in the cold
Keep power stations inside the heated space during use, and check the maker's charging and discharging temperature ranges. Cold reduces available capacity and some units will not charge below freezing.
Figures marked as Wattstanding calculations show their working; product figures come from the sources on each product page. How we work