Coffee Machine Running Costs: Brewing Is Cheap, Standby Isn't

The short answer

Making coffee costs almost nothing. Heating 250ml of water from 15C to 93C needs about 0.023kWh of energy, and once you allow for the heating element, the pump and a bit of loss, call it 0.035kWh, or 0.9p at 26.11p per kWh.

Keeping the machine ready to make coffee is where the money goes. An espresso machine sitting hot at 80W for twelve hours a day costs about £91 a year, roughly a hundred times what it costs to brew the coffee you actually drink. This page is mostly about that gap.

Cost per cup

At 26.11p per kWh, and 1,095 cups a year, which is three a day.

The gap between the top and bottom rows of that table is £42 a year, and it is entirely about how much water you put in the kettle. Nothing about which machine you buy comes close to that.

Standby and keep-warm: the actual bill

Worked example for the espresso machine: 0.08kW × 12 hours = 0.96kWh a day, and 0.96 × 26.11p = 25.1p, which over 365 days is £91.

Traditional espresso machines with a heavy brass boiler are the extreme case. They are designed to be left on because heating that mass takes twenty minutes, and the whole appeal is pulling a shot on demand. The 80W is the price of that convenience, and it is a real number that nobody puts on the box.

The three changes that matter

Set the auto-off. Almost every machine made in the last decade has one, and it is frequently set to two hours or disabled out of the box. Fifteen to thirty minutes is plenty. On a machine that would otherwise sit hot for twelve hours, this alone is most of that £91.

Fill the kettle to the line you need. Most kettles have a minimum fill mark and a cup indicator. Using them saves £36 a year at four boils a day, which is more than any coffee machine's total annual electricity.

Use an insulated carafe instead of a hot plate. A thermal jug keeps filter coffee hot for hours with no power at all, and it does not stew it into bitterness the way an element under a glass pot does.

Descaling, briefly

Limescale on a heating element acts as insulation, so the element has to run hotter and longer to get the water where it needs to be. In a hard water area, which is most of the south and east of England, that builds up fast enough to notice within months as slower heat-up times.

Descale on the schedule the manufacturer gives, and use a filter in the tank if your water is hard. The energy saving is small. The saving on not replacing a machine with a dead element is not.

What to look for if you are buying

An auto-off you can set to fifteen or thirty minutes. A quoted eco standby figure, ideally under 1W. A thermal carafe rather than a hot plate on a filter machine. A descaling programme with a reminder, since the machines that nag you get descaled and the ones that do not, do not.

Beyond that, buy the machine that makes coffee you want to drink. The running cost difference between the best and worst options here is a few pounds a year, and it should not be anywhere near the top of your decision.

Common questions

How much does it cost to make a cup of coffee at home?

Under a penny in electricity. Heating 250ml of water from 15C to 93C takes about 0.023kWh of energy, and allowing for heater and pump inefficiency call it 0.035kWh, which is 0.9p at the 26.11p per kWh cap rate. A bean to cup machine adds the grinder and a rinse cycle, taking it to about 1.3p. The coffee itself costs vastly more than the electricity that heats it.

Which type of coffee machine is cheapest to run?

Per cup, a pod machine, at about 0.8p, because it heats only the water for one shot and switches off. A filter machine is about 1.6p a cup for the brew, but that is before the hot plate, which is where filter machines lose. Bean to cup lands around 1.3p including grinding. The differences here are pennies a year, so choose the machine on the coffee, not the electricity.

How much does leaving a coffee machine on standby cost?

It depends enormously on the machine. A modern unit in eco standby draws under 1W and costs about £1 a year. An older bean to cup machine keeping its boiler warm at 15W costs about £34 a year running around the clock. A traditional espresso machine with a large brass boiler left hot at 80W for twelve hours a day costs about £91 a year. Standby, not brewing, is where the money goes.

Does a filter machine hot plate use much electricity?

More than the brewing does. A hot plate typically draws about 40W, so four hours a day adds 0.16kWh, which is 4.2p a day or about £15 a year. It also stews the coffee. A machine with an insulated carafe and no hot plate keeps the pot drinkable for longer and costs nothing to do it.

How much does overfilling the kettle cost?

About £36 a year if you do it four times a day. Boiling 500ml, roughly enough for one large mug, takes about 0.052kWh, or 1.4p. Boiling a full 1.7 litre kettle takes about 0.18kWh, or 4.7p. Over 1,095 cups a year that is £15 against £51. Kettles are among the highest-wattage things in the house, so the habit is worth more than the appliance choice.

Does descaling save energy?

Yes, modestly, and it saves the machine, which matters more. Limescale on a heating element is an insulator, so the element runs hotter and longer to deliver the same water temperature. In a hard water area, scale builds fast enough to be noticeable within months. Descale on whatever schedule the manufacturer specifies, and use a filter in the tank if your area is hard.