Sunday May 29 2022, 12.01am, The Times
George Nixon
It might be getting into summer now, but even if you’ve turned the heating off, your energy bills are still more expensive since the price cap rise in April. Every unit of electricity you use is 33 per cent more expensive than it was before April and every unit of gas is 75 per cent more — and they will rise again in October.
The only sure-fire way to keep a lid on your bills is to cut how much you’re using. But not all energy saving tips are equal. Here are the ones worth doing.
Before you start . . .
You need to work out how much energy the appliances in your home consume.
You’ll find power consumption information in those dusty old booklets for your dishwasher, microwave or fish tank, or you can look up a device online.
If this is in watts you’ll need to convert it to kilowatt hours (kWh), the standard unit of energy measurement for electricity and gas prices.
To do this multiply the watts by the number of hours you use a device for at a time then divide it by 1,000 (the number of watts in a kWh). If you use a device for minutes instead of hours, multiply the watts by the minutes then divide by 60 first.
Multiply your kWh figure by the cost of your gas or electricity to find out how much each use costs.
For example if you have a 2,500w kettle that takes two minutes to boil you would multiply 2,500 by two to get 5,000, then divide by 60 to get 83.33. Divide by 1,000 and you get 0.0833kWh.
You then multiply this by the price you are paying per kWh of electricity — under Ofgem’s latest energy price cap it is 28.34p (for gas it’s 7.37p) and you get 2.36, or 2.36p to boil the kettle.
A further wrinkle, though, is that the product information cannot always be taken at face value. If you want a more precise reading, you can use an electricity monitor or consumption meter. You can plug this in between the mains socket and your appliance to see how much it costs to run. They are available online for about £15.
Efficiency makes a big difference to the cost of appliances. The most energy-efficient fridge-freezer, the LG GBB92MCBAP, costs £40.63 a year to run at the current price cap, according to the consumer group Which?, while the least efficient fridge it tested, the Hotpoint FFU3D W 1, costs £178.66.
When you need a new appliance, check the energy rating before you buy. The most efficient are graded A.
Should I boil my water in a kettle or on the stove?
If you’re boiling water to cook pasta should you fill up the pan with boiling water or boil it on the stove?
Boiling one litre of water from 20C to 100C requires 0.09kWh of energy, but because the appliances we use to heat it are not 100 per cent efficient the energy used will be more.
An electric kettle is about 80 per cent efficient, so would take 20 per cent more energy to boil the same litre of water, while a gas hob is about 30 per cent efficient and need 70 per cent more. A kettle would use 0.11kWh to boil one litre, and the hob would use 0.15kWh and do it slower.
But even though it takes longer and is worse for the environment, boiling water on a gas hob is cheaper, costing 1p a litre versus 3p in an electric kettle because gas is cheaper per kWh.
Modern electric hobs can be about as efficient as a kettle, while induction hobs can be up to 90 per cent efficient.
If you’re worried about the environment, use the kettle, if money is the priority and you have a gas hob, use that.
More crucial is to boil only as much as you need. A standard mug is about 300ml, which would require 0.03kWh of electricity to boil in a kettle, costing 1p. That’s against 3p to boil 1l or 5p if you filled up a full 1.7l kettle.
Would buying a big chest freezer help me save money in the long run?
Everyone seems to be embracing bulk-buying, batch-cooking and deep- freezing food to save money on shopping and cooking. It’s certainly a good way of cutting down on food waste. But be wary of getting an additional appliance — it’s still cheaper to run one large fridge-freezer than a small fridge and bigger chest freezer.
A small fridge with a capacity of about 34l uses about 61kWh, so would cost about £17 a year to run. Add to that a medium-sized chest freezer with a capacity of 150l to 299l and you consume roughly 230kWh a year, costing about £65 and taking the total to £81.40.
The LG fridge-freezer found by Which? to be the most energy efficient has 233l of fridge space and 107l of freezer space, and costs £40.63 a year to run, so you would be doubling your costs to get that extra freezer space.
But where there is money to be saved is in how you cook, freeze and defrost.
Which? said that a typical electric fan oven costs about £55 a year to run on average, based on five hours of cooking a week at 170C. That works out at about 21p per hour, £1.05 a week.
But you could use your oven less by batch cooking. If you cooked a double portion two nights a week and ate the leftovers on two days so that you only cooked five nights a week you would save about 30p a week, and potentially more if you also boiled less water and used the hob less as a result.
If you need a new oven then one of the most energy efficient models is the AEG BPK948330B.
Let anything you’re going to freeze cool to room temperature first, so your freezer doesn’t have to work as hard (this will also reduce risk of food poisoning). When defrosting, leave the item in the fridge overnight rather than microwaving just before you need it.
An 800W microwave has a power consumption of about 1270W (like everything it’s not 100 per cent efficient), although the defrost mode generally uses about 30 per cent of that, about 381W. If you defrosted something in the microwave for 10 minutes it would use 1.8p of electricity you could save by letting it defrost in the fridge.
Will a slow cooker save me money?
It can take about eight hours to cook a stew in a slow cooker on a low heat, compared with about three hours to cook the same stew in a typical fan oven at a cost of about 60p.
Lakeland’s 6l slow cooker on its low setting consumes 90w with a six-to-eight-hour cooking time. For eight hours that’s 0.72kWh, or 20.4p of electricity. On high it consumes 120w and takes three to four hours. Assuming four hours, that’s a consumption of 0.48kWh, or 13.6p of electricity.
So the cheapest option is to use the slow cooker, particularly on a high setting, but it does depend on what you are cooking. If you could make the meal in the oven in a hour or less, then that could be the cheaper option.
Should I turn off all those plugs?
Let’s face it, going round the house and turning off every sockets is a faff. Yet one of the most common energy saving tips is that you can save money — anywhere from £30 to £55 — by switching off so-called “vampire devices” sucking power from the plug day and night. The claim is that your TV, microwave, computer and other devices consume huge amounts of energy on standby mode.
However, since 2013, appliances like computers, games consoles, microwaves and TVs have had the amount of power they consume in standby capped at just 0.5w under EU and now UK rules. A device that consumes 0.5w amounts to 4.38kWh of consumption if it was left on all year, for 8,760 hours, it would cost £1.24.
To save the £35 a year the government organisation the Energy Saving Trust claims switching off standby devices saves you, you would need a total of 28 devices such as TVs, microwaves, laptop chargers and games consoles, and that’s assuming you never actually wanted to use them.
As far as energy consumption in your home goes, it’s unlikely to be the biggest culprit or save you much money.
Should I use the tumble dryer or hang my washing on the radiator?
Drying your clothes outside or on a rack in a well-ventilated spot in your home is undoubtedly the cheapest method of getting them dry.
But what if it’s wet outside or your clothes do not dry well inside?
First things first, don’t hang them over the radiator. It blocks it and makes your boiler work harder to heat your house. The boiler has to heat the damp clothes first before being able to heat the air. It takes four time more energy to heat water than air, and it’s the air temperature that your thermostat is measuring. Drying on radiators can also lead to damp problems in your home.
If you’re looking to save money, you should leave your tumble dryer well alone. Even the most efficient dryer around, the Miele TCB 140 WP, according to Which?, consumes 1.7kWh of electricity for a full 7kg load taking 155 minutes or 0.96kWh for a half load taking 95 minutes. That will cost 48.2p per full load or 27.2p for a half load. Other dryers can cost £1.50 per cycle.
A cheaper thing to use, if you have one, is a heated clothing rack. Lakeland’s heated airer (£150), which can hold up to 15kg of washing, has a power consumption of 300w. If you ran it for two hours that would be 0.6kWh of consumption, which would cost 17p.
Should you run appliances at night?
Running appliances like dishwashers, tumble dryers and washing machines at night, when there is less demand for electricity and it’s cheaper, is also often suggested as a way to save money.
But this only works if you’re on a tariff that gives you cheaper electricity at this time. These are known as Economy 7 or 10 tariffs, which give you cheaper electricity at off-peak times for seven and ten hours respectively.
The flipside of this is that peak-time rates are more expensive, so if you still use a lot of electricity in the daytime, you might find yourself paying more.
Scott Byrom, from the comparison site the Energy Shop, said these tariffs are often useful for people with electric storage heaters that can be warmed up at night, those with appliances that can be put on using a timer, or those working shifts outside of normal working hours.
He said you would have to be using at least 30 per cent of your energy consumption in the off-peak period in order to benefit from one of these tariffs.
Should I turn off radiators in rooms I’m not using?
Many people use an electric radiator to heat up one room without turning on the central heating. But these can be very expensive to run, at about 2kWh for every hour of usage (56.7p).
The Money Saving Expert founder, Martin Lewis, has an adage you should “heat the human not the home”, so a better thing to consider is an electric blanket or throw. These consume much less electricity, about 0.15kWh (4.3p an hour), 13 times cheaper than an electric heater.
These can cost up to £60, however, so if you don’t have one, a cheaper alternative is a hot water bottle wrapped up in a pillowcase or blanket. Boiling enough water on a gas hob to fill a 1.5l hot water bottle would consume 0.45kWh of gas, and cost 3p to do so. Use the kettle and it will cost 4.7p.
Are LED bulbs really worth investing in?
The energy saving tip that makes by far the biggest difference, apart from just turning your heating off, is changing your lightbulbs.
The sale of halogen bulbs was banned in October, and replacing them with LEDs saves the cost of new bulbs several times over. Plus they also last about 12.5 times longer, said Which?.
A 700 lumen halogen bulb would consume 42w of electricity, while an LED producing the same level of light would consume 10. If left on for 1,500 hours a year (about four hours a day), the halogen bulb would cost £17.85 to run and the LED would cost £4.25.
If you swapped out ten old lightbulbs, for a cost of about £20, and used them all that often, you would still save £116 a year after earning back the initial outlay.
Is a bath really that much worse than a shower?
It depends on how long you stay in the shower. The average 90l bath contains 30l of cold water and 60l of hot water, according to the boiler manufacturer Worcester Bosch, while an average shower dispenses 9l of water a minute, 6l of which is hot (about 42C).
The cost of heating a litre of water to that temperature from 5C is about 0.04kWh. That would mean running 60l of hot water in a bath would use 2.4kWh, which at the price of gas would be 17.69p.
Dispensing 6l of hot water a minute, a shower powered by your gas boiler would cost 1.77p per minute, and an electric shower at the higher per kWh price of electricity would cost 6.8p per minute. These savings don’t take into account the cost of water, but if you don’t have a water meter then you’re quids-in.
The price difference means if you shower in less than ten minutes with a boiler-powered shower it will cost you less than running a bath. If you have an electric shower, you have two and a half minutes. Get scrubbing.
