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An electric glass-top stove looks like the sensible modern choice. No smoke, no ash, no open flame — just heat at the touch of a button. An open fire, by comparison, looks primitive and wasteful. Dirty, even.

That comparison only holds up if you stop looking the moment the electricity reaches your kitchen. Follow it back to where it actually comes from, and the story flips.

Efficiency at the wall isn’t efficiency at the source

When people call an electric hob “efficient,” they mean efficient at the point you use it. Plug it in and roughly 70-80% of that electricity becomes heat under your pot, which sounds like a genuinely good number.

But that electricity had to be made somewhere first, and that’s where most of the waste actually happens.

A power station — coal, gas, nuclear, take your pick — burns fuel to boil water, spins a turbine, and generates electricity at around 30-40% efficiency. The other 60-70% of the energy in that fuel gets thrown away as waste heat, dumped up a cooling tower or straight into a river. Then the electricity has to travel down high-voltage lines and through transformers to reach your house, and another 5-10% gets lost to resistance in the cables before it ever reaches your kitchen.

Add it up — the power station, the grid, your hob — and boiling water on electricity works out at roughly 20-25% overall efficiency once you trace the whole chain. That’s the real number, and it never appears on the box.

Burning fuel to boil water, spinning a turbine to make electricity, sending that electricity down miles of wire, then using it to heat a pan again, is a genuinely wasteful way to boil an egg. Nobody questions it because the waste happens out of sight, in somebody else’s cooling tower, long before it reaches your worktop.

A well-tended fire beats the grid

Burn the fuel where you’re actually going to use the heat and you skip every one of those losses in one go.

A badly run open fire — wind scattering the flames, heat escaping in every direction — is genuinely poor, somewhere around 10-15% efficient. That’s the version most people picture when they think “primitive.”

Tend it properly, though, and the numbers change a lot. Block the wind, burn dry seasoned wood, keep the pot close to the coals, control the airflow, and efficiency climbs well past that. Push it further with an insulated rocket stove, which channels the hot gases tightly around the pot and burns the fuel more completely, and you can reach 40-50% primary efficiency. That’s roughly double what your electric hob manages once you count the entire journey from power station to plate.

Done properly, the “primitive” fire beats the “modern” appliance. That’s simply not the story the appliance box tells you.

The haybox: cooking without a flame

Most of the energy wasted in cooking isn’t spent bringing food to the boil. It’s spent keeping a pot simmering for the next hour or two, with a flame or an element running the whole time just to hold a gentle bubble.

The old fix for this is the haybox, sometimes called a fireless cooker, and it’s almost embarrassingly simple. Bring your stew, beans, or grains to a full rolling boil for five or ten minutes, then take the pot straight off the heat and pack it, tightly sealed, into an insulated box — hay, wool, sawdust, an old duvet, whatever’s to hand. Because almost no heat can escape, the food keeps cooking gently on its own stored heat for hours, with no flame, no electricity, and nobody standing over it.

For a long-simmer meal, that can cut total fuel use by up to 80%. All for the price of an insulated box and a bit of patience.

What I recommend

• Thermos Vacuum Insulation Cooker Shuttle Chef 4.5L

What to actually do with this

You don’t need to go off-grid to use any of it.

• Stop treating electricity as free efficiency. It’s a high-grade energy source, and using it for bulk heating jobs like boiling several litres of water wastes what it’s actually good for, unless it’s coming straight off your own solar panel.
• Build or buy a simple insulated cooker and finish long-simmering meals off the heat entirely, rather than leaving the hob running for hours.
• Use a flat-bottomed pot with a tight lid. It sounds obvious, but most people don’t bother, and lose heat out the sides the whole time they’re cooking.

Believe the efficiency number printed on the appliance if you want. Or trace the fuel back to where it started and work out for yourself where the energy’s actually going. That’s up to you.