Gas vs electric: which fuel for which job?
Gas costs about 6.5p per kWh against 26p for electricity, but electricity wins wherever you can heat something small and targeted instead of something big.
Our Setup
Our home runs on gas central heating and a gas hob, with electric everything else and a day-night electricity tariff. So this isn't theory. It's the daily decision we make in our own kitchen: which ring, which appliance, which fuel.
Heating: gas wins, almost always
A modern gas boiler turns roughly 90% of its fuel into heat. Even after those losses, a kilowatt-hour of warmth from gas costs around 7.2p, against 26p from any electric heater. Running the whole house on gas for an hour costs about 33p; a single 2,000W fan heater costs 52p for the same hour and heats one room.
The one exception: when you're home alone in one room, heating the whole house to warm one person is the wrong-sized job. Turn the other radiators down, and warm you: a heated throw or desk mat costs pennies a day.
Read the working-from-home heating guideCooking: the hob is gas's home turf
| Job | Best fuel | Why |
|---|---|---|
| Big pan of pasta or veg water | Gas hob | Bulk heat, cheap per unit |
| Sauces, stews, long simmers | Gas hob | Hours of low heat |
| One mug of tea | Kettle | Heats only the water you drink |
| Jacket potato, chips, small bakes | Air fryer / microwave | Heats a small space, fast |
| Reheating leftovers | Microwave | Minutes, not preheating |
The pattern: gas loses a lot of heat around the pan, but at 6.5p per kWh it can afford to on big jobs. Electric appliances win by barely wasting anything: a kettle or microwave puts nearly all its energy into the food or water, and only runs for minutes.
- A gas hob is only about 35–40% efficient (much of the flame's heat escapes around the pan), but gas is cheap enough that a big pan of water still costs less on gas than in an electric kettle.
- A kettle is around 80–90% efficient and heats exactly the water you need, so for one or two mugs it beats the hob on speed and waste, as long as you only fill what you need.
- An electric oven cycles on and off, averaging roughly half its rated power, but heating a big oven cavity for one small dish is the wrong-sized job, which is why the air fryer wins.
- Boiling a big pan of water, about 10 minutes on a full ring: roughly 2.2p.
- Frying or sautéing, 30 minutes at medium heat: roughly 4.9p.
- A long simmer, an hour on a low ring: roughly 3.3p.
Typical ring inputs, not measured results; burners vary between hobs. At these prices everyday hob cooking costs pennies, so there's no need to move a gas hob job to an electric gadget unless the gadget heats something smaller and finishes faster.
Hot water: let the boiler do it
If your gas boiler heats your hot water cylinder, hot tap water costs roughly 7.2p per kWh of heat, about a quarter of what an electric immersion heater would charge for the same water. Baths, washing up by hand and the hot tap all belong on gas. The immersion is the expensive backup, not the everyday option.
Worth knowing
Never use a gas hob or oven to heat a room: it wastes gas and fills the kitchen with moisture and fumes.
- Overnight electricity at 7p or less changes the sums: a slow cooker or dishwasher run overnight can undercut gas.
- Daytime is the expensive window: that's when the gas hob earns its keep for cooking.
- Everything above flips: without gas, the cheapest heat is the most targeted electric heat.
- Induction hobs are far more efficient than old electric rings, closing much of the gap with gas.
- Cooking on a ceramic or solid-plate electric hob? Long simmers there cost several times the gas figures above. Electric hob homes get their own guide.
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