Ways to reduce energy use and lower home cooking costs

Cooking a jacket potato in the oven can use more than 40 times the energy of making it in a microwave. And putting a dishwasher on its eco cycle could reduce energy and water use by about 30%.

For anyone trying to bring down household bills, experts say a few small kitchen changes can add up to a noticeable saving.

The price of preparing food is not just about ingredients. Hobs, kettles and fridges all contribute to the total energy bill.

One of the best places to start is by using the oven less, says Prof Sarah Bridle from York University, because you are heating both the food and a large metal box.

"Using the oven only on special occasions is the single most impactful thing an individual can do [to reduce cooking-related energy use]."

Microwaves, slow cookers, electric pressure cookers and air fryers all use far less energy than ovens, although each works best for different types of cooking.

Different appliances, different uses

Microwaves

Microwaves are useful for defrosting, reheating food and drink, and cooking vegetables.

Slow cookers

Slow cookers are well suited to curries, stews and soups, and use roughly the same energy as an old-style non-LED lightbulb, says Dr Christian Reynolds from the Centre for Food Policy at City University, London.

Electric pressure cookers

These cut cooking times sharply, making them ideal for dried beans or for turning tougher cuts of meat such as brisket soft and tender in less than an hour.

Air fryers

Cooking in an electric oven costs more than twice as much as using an air fryer. However, air fryers are smaller, so you may need to cook in batches if you are preparing a large amount.

If you do use the oven, try these tips:

• Switch it off 5-10 minutes before the end of the cooking time so the food finishes in the remaining heat. This works well for casseroles, pies, roasted vegetables, shepherd's pie and lasagne.

• Cook more than one item at a time so you get more value from the energy used.

• Stay in the kitchen, where it is already warm, rather than heating other rooms in the house.

You can also save by combining appliances in smarter ways.

• Microwave then crisp: Part-cook potatoes or vegetables in the microwave, then finish them in an oven or air fryer to crisp them up.

• Hob then slow cooker: Brown meat first for flavour, then move it to the slow cooker.

• Bulk-bake potatoes: Poke, salt and bake them once, then reheat later in the microwave.

If you are cooking on the hob, use a lid to keep the heat in — Dr Reynolds says this can cut energy use by about 30%.

He also points to two easy wins:

• Use the right size pan. "Filling up a 20-litre pan to cook pasta for one is a waste of money," he says.

• Boil water in an electric kettle. They are more efficient than a pan on a conventional electric hob. If you boil extra for several cups of tea, pour the rest into a vacuum flask to keep it hot for later.

Fridge-freezers account for 13% of household energy bills, according to the Energy Saving Trust. To keep them running efficiently:

• Let hot food cool before putting it away.

• Defrost food in the fridge, which helps keep the temperature down.

• Do not leave the door open.

• Keep the temperature between 3C and 5C (37-41F). You can check this by leaving a thermometer in a glass of water on the middle shelf for 12 hours or overnight.

• Defrost the fridge-freezer regularly so it does not have to work harder through ice build-up.

Dishwashers use energy to heat water and run cleaning cycles, but there are ways to reduce that cost. Try the following:

• Run one fewer load a week: The Energy Saving Trust says this could save £14 a year.

• Wait until it is full before starting it.

• Use the eco setting even if it takes longer: Which? says it uses 30% less energy and water than the main programme.

If an appliance breaks or you need an upgrade, look at the energy label and choose the best-rated model that fits your budget and needs. Options to consider include:

• Induction hobs: The Energy Saving Trust says these are usually the most energy efficient.

• Gas hobs: They may be cheaper to run, but they can affect air quality.

• Slow cookers: These start at about £20, and the savings can repay that fairly quickly.

Energy use compared

Baked potato

• Oven (120 minutes) = 6.07kWh

• Microwave (10 minutes) = 0.14 kWh

• Half microwave (five minutes), half oven (30 minutes plus 15 minutes warm-up) = 2.34kWh

Boiling water for one cup of tea

• Electric kettle (2 minutes) = 0.07kWh

• Pan on electric hob (5 minutes) = 0.18kWh

• Microwave (4 minutes) = 0.05kWh

• Induction hob kettle/pan (2 minutes) = 0.14kWh

Reheating stew

• Electric hob (12 minutes) = 0.43kWh

• Oven (45 minutes) = 2.27kWh

• Microwave (8 minutes) = 0.11kWh

• Induction hob (5 minutes) = 0.35 kWh

Porridge

• Microwave (5 minutes) = 0.07kWh

• Electric hob (10 minutes) = 0.36kWh

• Induction hob (5 minutes) = 0.35 kWh

Source: Based on data from Prof Bridle and on Wattage numbers from Supplementary Data of supplementary table of Frankowska et al.

To save money, use the oven less, handle the fridge-freezer efficiently and rethink the way you cook.

The savings may not be dramatic straight away, but over time these habits can make a real difference.