This basically comes down to the food you’re cooking and the way you’re cooking it, but you don't necessarily need to invest in a state-of-the-art low-energy-using oven to improve the energy efficiency of your kitchen. Being more mindful of your cooking processes can significantly reduce the amount of energy you use and cut your energy bills in the process.
With that in mind, we’ve pulled together more than twenty simple, common-sense tips to help you become a more energy-conscious cook. You probably won’t use them all when preparing every meal, but knowing about them and practising them when required will definitely make a difference to your energy usage and your wallet.
The microwave is generally the most efficient way to heat up and cook food - it’s always quicker and its smaller size (as opposed to the oven) means that the heat is more focused on whatever’s being cooked. Opt for this appliance whenever possible.
Use the kettle to boil water quickly and transfer to a pan on the hob for steaming and boiling vegetables or pasta.
When using water to boil anything in a pan, make sure that you only use as much water as is needed to cover the amount of food you’re cooking - one of the most common forms of energy wastage is the energy it takes to boil water you don’t need.
Slow cookers are also an energy-efficient cooking appliance - they use just a little more energy than a traditional light bulb, and you can leave your food to cook slowly throughout the day while you’re at work or when you need to get on with other things.
Cook as much as possible in the oven in one go to make sure all the space and heat is being used. If you make lunches for work, do them all at once - you can always keep them in the fridge or freeze them to warm up when you need them.
Keep the oven door closed while you're cooking. Each time you open the door, the oven loses heat (sometimes as much as 25 degrees) and requires more energy to get back up to temperature. On a similar note, try to keep the oven door clean so you can look in, rather than having to open it to see how your food is doing.
Defrost frozen food in the fridge overnight or while you’re at work during the day. Defrosting food in advance not only typically halves the cooking time but also means that you don’t need to use the energy of a microwave to defrost more quickly - you just need to remember to take the food out of the freezer well before you need it!
It’s helpful to know how long your oven takes to pre-heat, so you're ready to start cooking as soon as it's up to the correct temperature.
When cooking potatoes, boil them in a saucepan before roasting them in order to reduce the amount of time they take to cook in the oven.
Use glass or ceramic dishes in the oven. They retain heat better than their metal counterparts, making them the most efficient to use in the oven. You can even set the heat lower than needed (if you’re confident enough to do so) because of the increased efficiency provided by these dishes.
Some people think that inserting stainless steel skewers into baked potatoes and joints of meat can help to speed up the cooking process because the heat is more quickly and evenly conducted throughout the food while it’s in the oven.
If you’re cooking large food like a joint of meat, it can be worth cutting it into smaller pieces so it will cook more quickly. Additionally, if you use this method on meat, you should also be able to avoid overcooking it.
Invest in a fan-assisted or convection oven, which uses fans to circulate heat around the food as it cooks. This is a more energy-efficient way of cooking because it means the heat doesn’t have to be as high as it would in a conventional oven.
When using an electric oven, turn it off ten minutes before the food’s finished cooking. The oven temperature will remain the same so the food will still cook through to completion without the oven using energy.
Always use a pan which is the right size for the amount of food you are cooking to ensure that you use less energy in heating a bigger surface area when you don’t necessarily need to.
Similarly, when you’ve selected your pan, make sure you use the right size hob for it. A bigger burner will waste energy and a pan that’s too big will take longer to get to the right temperature.
Sometimes the instructions on a recipe may mean that it’s not a good idea to put lids on pans but, if not, use lids in order to keep the heat in.
Use a double steamer to cook vegetables so you can layer vegetables on top of each other and still use one ring.
Turn down the level of the ring or burner once the cooking temperature or state is reached; most dishes need to simmer, not boil.
It can often be worth using a pressure cooker to cook beans, meats, whole meals or stews. The pressure cooker’s sealed lid traps steam and ensures that the food cooks more quickly and efficiently than it would in a pan, therefore saving energy.
If you're using an electric hob, choose flat-bottomed pans so the pan is in full contact with the ring and the heat spreads through it as evenly as possible.
Certain pan types are better at conducting and retaining heat. Copper-bottomed pans heat up more quickly than stainless steel, and cast-iron pans retain heat more efficiently, so you won't need the heat to be turned up so high.
Keep heating rings as clean as possible - any food that sticks to the ring will absorb heat, making it less efficient.
Energy efficiency when cooking will naturally be influenced by the actions you take when preparing every meal, but the appliance you use can also have a bearing on how much energy you use and how expensive your bill is at the end of the month. But what’s more energy-efficient: a microwave or an oven?
As far as speed of cooking is concerned, it’s fair to assume that the microwave must be the most energy-efficient appliance to use. To an extent, this is true, but it’s unlikely you’re going to be using it for any particularly complicated recipes, which is where its advantage as a speedier cooking option would probably be the most telling.
The easiest way of judging the energy efficiency of any appliance is to examine the cost per unit of energy used. Uswitch research using a smart meter indicates that a microwave costs 21p per hour of use. However, it’s unlikely that you would use it for a full hour so the actual cost would probably be much lower.
The oven is the most commonly-used appliance because of its versatility - it will usually include hobs to fry or boil food, a grill and an oven. However, Uswitch research indicated that there is little to choose between the oven and the grill in terms of the cost of using them, with the oven costing 18p per hour of use. However, you’d usually use the oven for longer than you would use a microwave, so the amount of money it costs per use is probably more or less the same.
Slow cookers are among the kitchen’s most energy-efficient appliances. Although they take longer to cook food, they’re rated at as little as 200 watts – less than a tenth of some electric ovens. An average-sized slow cooker uses just 1.3 kWh per meal cooked, which when broken down to an hourly cost comes in at under 1p on the average energy tariff. This can be further reduced if you have solar panels, as you can set the cooker to run during daylight hours when some or all of the electricity will be free.
There are numerous ways you can cut your energy consumption when cooking, but the most effective step is to audit your current appliances to see if switching to a more energy-efficient alternative is cost-effective.
Start by examining your oven or ovens. On average, electric ovens have a power rating of 2.0-2.2 kWh, which means they consume between 2,000 and 2,200 watts for every hour they’re being used on a medium-to-high heat. From March 2021, the old energy ratings system is being phased out in favour of a simple A-G system, so look for gas and electric ovens that come with A (if launched after March 2021) or A+ (if launched before March 2021) ratings.
Also take care when choosing an oven for its features – for example, check out the oven’s insulation levels (including its doors – look for triple-glazed models). The better this is, the more the oven retains heat to maintain its temperature and reduce the time (and thus energy) needed to heat it up.
On the other hand, while a self-cleaning ‘pyrolytic’ oven might sound attractive, it’s not very energy efficient. That’s because to remove the grime that’s baked on, the oven heats itself to 400-500 degrees Celsius to literally burn it off.
Yes: not only do microwaves use less energy (typically no more than 1,500 watts), they’re far more efficient as they only heat the food itself rather than waste energy heating the air around them. There’s no warming-up time – microwaves reach temperature virtually instantaneously, and food takes far less time to cook. When it comes to heating up food, microwaves win out over ovens every time.
Almost certainly – like microwaves, energy is more efficiently converted to heat (they reach temperature much quicker than regular electric hobs) using the hob’s electromagnetic burner, which heats the ceramic plate above it.
There are potential drawbacks that may make them impractical, however. First, they’re not suitable for anyone using a pacemaker (the electromagnetic field can interfere with the pacemaker’s settings) and second, they require specialist pans made from iron.
We boil our kettles 1,500 times a year on average. While a lower-wattage kettle might appeal, it takes longer to boil the water so is a false economy unless you have solar panels that may be able to offset most – if not all – of the electricity being used during daytime.
For everyone else, look for rapid-boil models in the 2.5-3.0kWh range that are designed to boil small amounts of water quickly. You should also look for a water indicator to ensure you only boil what you need, while other features that help reduce consumption include controls to heat to lower temperatures for hot drinks that don’t require boiling water, and insulated casings that keep the water hot for longer after boiling, reducing the need to keep re-boiling the kettle.
There is a growing trend for kitchens and oven manufacturers to use induction hobs, where an electromagnetic burner heats a ceramic plate that the pan sits on, as opposed to more traditional gas-ringed hobs. But which option is the most energy-efficient?
In terms of energy use, research generally indicates that induction hobs are cheaper to run, with induction hobs proving to be 74% efficient in converting energy to heat, using 57% less energy than gas hobs.
There’s also a question around how much impact an energy-efficient approach to cooking can actually have on the wider environment. You might save money on your energy bills, but is there anything you can do to be more green in the kitchen?
Most (if not all) of the tips above are designed to make you more energy-efficient in the kitchen, and the knock-on effect of that is a generally greener approach to cooking which benefits the environment as a whole. Employing them as much as possible will have a significant effect on reducing the energy you use and your overall impact on the environment.
You don’t necessarily need to buy a new appliance to ensure energy efficiency when cooking if the one you have works properly. If it isn’t working, though, it’s worth replacing - having a cooker in good working order is essential for energy-efficient cooking because it will help lower your fuel consumption and keep your gas and electricity bills down.
While you might be reluctant to buy a new appliance until the old one has stopped working, consider investing in a replacement if the existing appliance is over ten years old, regardless of whether it works properly or not. If the appliance is faulty and will be expensive to fix, it will usually be easier (and potentially cheaper) to just buy a new one rather than go through the hassle of having it repaired.
When it comes to oven-related issues that might affect energy efficiency, it’s worth checking that:
the door of your oven is properly sealed, as we’ve already noted, the amount of heat that leaks out during cooking has a big impact on the energy efficiency and energy consumption of an oven
your oven thermostat or fan still works, because if air isn’t circulated around the interior of the oven, the speed at which food is cooked will be reduced.
If you decide that you need a new oven and you decide to opt for an electric model, then it's important to choose an oven that is energy-efficient, as well as ensuring that it has triple glazing on the oven door and a good level of insulation.
The energy label on any appliance will tell you how energy-efficient it is. An appliance with an “A” rating is the most energy-efficient and can reduce long-term running costs. The most efficient appliances will also carry the Energy Saving Recommended badge, which is awarded by the Energy Saving Trust. With this in mind, make sure you’re getting an oven which is rated “A” for energy efficiency.