Information is split into a section on saving electricity assuming that your home is heated by gas or oil and a section about saving on heating. If your home is heated electrically, both sections still apply. If you have any questions please get in touch.

Part 1. ELECTRICITY

General comments

There are a surprising number of actions which help to save electricity in the home. Some save large amounts but tend to involve spending – new fridges or lightbulbs for example and some save small amounts by doing things differently. There are lots of these and they do add up to useful reductions.

The biggest potential savings are on refrigeration and lighting, and turning things off as soon as you’ve finished using them, especially if you have old equipment.

Refrigeration

For refrigeration, a new energy rating scale has just come into use. On it, refrigerators and freezers now have rating letters A to G instead of A+++ to D. The reason for the change is that under the old system most appliances available became rated A+ to A+++. On the new scale an old A+++ will be a D. This allows manufacturers to further improve efficiencies in an understandable way.

The question is, how old does a freezer need to be before its worth replacing. In 2007, the author bought an A+ freezer (probably an F on the new system) rated at 234kWh pa, (1.5m tall, 194 litres capacity) to replace a very old freezer of similar size. Measurements (more about which later) had shown that the old freezer was using about 700 kWh pa. Replacement was a “no brainer because” the new freezer would pay for itself in four years. Similar sized freezers currently available seem to be only slightly more efficient so it isn’t time to upgrade for us but I’d say that if you have a pre 1995 freezer that is still working, its time to consider replacement. If you still have the information about your old appliance telling you how many kWh pa it uses, compare that with candidate replacements. In addition to the letter coded efficiency, the Energy label tells you how many kWh per annum an appliance uses. This is much more informative than the letter code because not all similarly rated appliances use the same amount of energy. A large D rated appliance will use considerably more than a small D rated appliance. If you do not have information about the energy use of an old appliance you can borrow an energy meter from SCA to measure it. That’s how we knew our old freezer was using about 700kWh pa. Just email us and we’ll get back to you.

Lighting

LED lighting is now available for most situations and gives an excellent quality of light. Bulbs are still more expensive than the old fashioned filament bulbs but the savings rapidly cover the cost of the lamp as shown in the diagram below. If you still have any old fashioned bulbs which are on for several hours a day its definitely worth replacing them with LEDs. They will repay the cost of the bulb in under three months. We have one or two old fashioned bulbs in places like the under stairs cupboard where use is very infrequent and brief.

Whilst low energy compact fluorescent bulbs are not quite as efficient as LED’s, the case for swapping them out is less clear. In the diagram at right, it is assumed that you already have the bulb so its cost is not counted. On this basis, it takes over two years to recoup the cost of an LED of equivalent brightness. Its probably worth buying LED’s for main rooms where lights are on for long periods and using up the compact fluorescents in places where lights are only on for short periods.

A filament LED
The most efficient type of LED are the filament type. The efficiency of LED’s can be judged by dividing the stated light output (lumens) by the wattage. Filament LED’s are usually 110 to 130 lumens per watt whereas slightly cheaper frosted one can be as low as 50 lumens per watt, similar to compact fluorescents. For our unshaded lounge wall lights, we did decide to have LED candle bulbs that were frosted because the filament ones produced glare.

LED’s offer the possibility of white light tinted with slightly different colours, sometimes described as colour temperature. ‘Very warm white’ (1800 deg K) is quite orange/yellow. Warm white ( 2700 to 3000 deg K) is close to old fashioned lampsand usually the best choice. Cool white at about 4000 deg K is good in kitchens and bathrooms. Daylight at 6000 deg K has a slight bluish tinge and isn’t particularity suitable in most domestic situations unless you like that effect.

LED GU10 spotlights are excellent energy savers compared to conventional GU10’s. They have the added advantage of very long lives, so removing the hassle of changing bulbs in the ceiling which are somewhat inaccessible.

A note of caution if your ceiling spotlights are MR16 (low voltage). It is quite common for the transformer supplying them to be unable to work at very low power resulting in flickering or no light. A possible way round this is to change some of the bulbs for LEDs. Its a matter of trial and error to find out how many so buy two or three and try them. If Ok, try another two.

Doing things differently to save electricity

There are many actions in this section and its impossible to take them all on at once so pick one or two and get used to doing them, then gradually add more. Some may seem difficult or even crazy and not for you so pick things you think you can do and then give some of the more difficult ones a try.

Freezers/refrigeration.

Every time the door is opened, cold air falls out and warm air is sucked in to replace it. This happens very quickly (stand in front of the freezer in bare feet and open the door to see just how quickly). The warm air then has to be cooled so extra electricity is used every time the door is opened and the longer the door is open, the more warm air gets in. Similarly, warm food should be allowed to cool to room temperature before putting it in the freezer. This is a double win because as the food cools, it gives up heat to the room thereby saving a little on heating as well as avoiding extra electricity to cool it down in the freezer. A similar double win can occur when defrosting frozen food. Putting it in the fridge to defrost the day before it is needed allows the cold in the frozen food to escape into the fridge thereby saving a little electricity. Think of this as recovering some of the electricity used during freezing. The absolute opposite of this is using the microwave or hob or oven to defrost. Here instead of benefiting by defrosting in the fridge, extra energy is used to defrost.

If the freezer gets a build up of ice inside, it needs defrosting. The thicker the ice, the harder the freezer needs to work to pump heat from within. This is best done in summer so the melting of the ice does not rely on heat from the heating system. I once saw a tip for defrosting involving the use of a hair dryer but this is hardly an an energy efficient process! Allowing the freezer to defrost with contents removed and wrapped in blankets, cool boxes etc is the low energy way to defrost. If its accessible, an occasional gentle dusting of the heat exchanger at the back of the freezer or fridge is also worth doing to ease the outward flow of heat.

Lighting.

Even if the plan is to return quite soon, aim to develop the habit of switching off on leaving any space which has nobody still in it. By doing this, the situation where lights are on all over the place is avoided. Whilst any one LED light does not cost a lot to run, a houseful of burning lights does cost and if nobody is benefiting from most of the lights, its an avoidable cost. We have one exception to this. We regularly carry trays from kitchen to lounge and we found that trying to switch lights was inconvenient/difficult. So, we now have a table lamp with a lowish wattage filament LED instead of burning the two hall ceiling lights.

Electronics

These can be the invisible electricity guzzler because most electronics (radios, CD player, Sound systems, TV, PC, etc) are usually not completely off unless switched off at the wall or unplugged. It doesn’t use very much so its OK to leave it on. This appears to be true for small items like mobile phone chargers, TV on standby etc. However, the average home has over a dozen little things each not using very much and a dozen little things do add up to a big saving if you turn them all off when not in use. Many things, in fact most things, are not off unless you switch them off at the wall socket or unplug them.

Below is a list of the power in watts of many little things. Different makes and models vary so the list gives typical values and sometimes the maximum, found by taking measurements from a group of items of different makes:-

Approx annual saving if all turned off = £200 and about 0.5 Tons of Carbon pollution.

Is it easy to achieve savings? Yes. Professor David Mackay in his book ”Sustainable energy without the hot air” reports that just by turning off two stereos, a DVD player, a cable modem, a wireless router and an answering machine, he saved 45 watts and about £67 per year at current prices. We saved a similar amount by switching off at the wall an old PC and its monitor (that we hardly ever used) and our newer PC, its monitor, speakers and printer. Count up how many of the above you have switched on.

The list above was gathered a few years ago. Since then, directives have mandated that most new equipment has a maximum standby power of 1 Watt. So the savings that are possible depend on the age of the electronics.

Some ideas:-

1. Use BT answer or equivalent and put the answer phone away.

2. A short extension cable with switched sockets can overcome the problem of inaccessible socket switches.

3. Reduce pocket money if stuff is left on.

4. Pay extra pocket money for reminders from the kids to switch stuff off that you left on.

5. Learn how to reprogram the time in video/dvd recorders so you can turn them off at the wall. Practice a few times so you can do it quickly without having to refer to the book. Our old recorder used 14 watts so there was a good saving here by being able to quickly re-enter the time if we wanted to record something.

6. If you need to leave your PC with something half done, save it and put the PC into standby or sleep. That will change 40 watts or possibly considerably more to just a few watts while you are away. When you come back hit a key to wake up the PC and log in again and within a few seconds you are back where you left off.

7. Turn off your security light during the day to save 4 Watts.

8. PC screen savers are not energy savers. In fact an old PC left on screen saver can be one of the biggest energy users in the home.

A special section for PC’s and TV’s

As mentioned above, a PC running a screen-saver can be very expensive. During the day, PC’s should be put to sleep or standby when not in use.

A PC and its router and monitor should be switched off overnight or when out during the day. To make this easier we have the PC, router and monitor on a multi-plug adaptor so a single switch can turn all 3 off after shutting down. The printer is on a separate switch so after shutting down it can be turned off at the mains and left off even when the PC is in use. The printer may not be used for many days at a time. A double switched socket on a short tailing lead sits on the desk at the back of the monitor to make switching easier.

Turning the brightness down on the monitor gives a worthwhile saving. We found it could go down from 100 % to 15% with only very slight loss of image quality. This saves 12 watts when the PC is in use. The monitor is a flat screen LCD monitor but if you have an old cathode ray (CRT) monitor, savings are likely to be much higher.

Just as with lighting, a TV playing in an empty room is wasting energy, almost certainly more energy than if the light was left on. Although standby power can waste energy if used all the time, its Ok to use the remote to turn of for short periods of time if you are coming back into the room soon. However, the TV and all associated equipment should be off at the wall overnight or when you are out during the day.

If buying a new TV, its best to avoid large screens because just as with large fridges and freezers, large uses more electricity than small. The manufacturers prefer to sell you a large one because they make more money on them.

In the Kitchen

The energy eaters in the kitchen are the kettle and the oven.

The Oven

Notice how warm the kitchen gets when the oven is on. This is due to heat leaking out of the oven. On current prices, (Oct 2021) electrical heat is 4 times more expensive than heat from gas, so the electric oven is an expensive way to heat the kitchen. Wherever possible :-

Use the microwave, slow cooker, pressure cooker or pan on the hob with a lid instead.

Make good use of oven space by cooking several things at once

Turn the oven off a few minutes before the end of cooking time.

Put things into a cold oven rather than preheating. (This is in the instructions for our Bosch oven but it only applies to some things so consult your manual if available. As a guide, preheating is required when baking but not for other cooking)

The Kettle

You’ve no doubt heard the advice to boil only the amount of water needed but somehow its hard to do this. There’s a fear that maybe there’s not quite enough in the kettle so the result is that more gets boiled than necessary. One way we found that helps is to put water into a cup so you can see the right amount. To make a cup of coffee to which milk will be added, three quarters of a cup of water (or slightly more if you like it less milky) is measured in the cup and put in the kettle. This might put the level below the kettle’s minimum which in kettles where heat comes from a flat bottom, is ok provided you switch off as it comes to the boil rather than allow the automatic stop. However, in kettles where the heating element is visible, the element must be fully covered. You’ll find boiling is really quick, just giving time to find the coffee, a spoon and maybe get coffee into the cup. The time to switch off is just before real boiling has started. The heat still in the element will complete the boiling. Why is this important? For every cupful of water boiled, 25 cupfuls of CO2 are released. Switching off manually can save 12 to 25 cupfuls of CO2 depending on how responsive the automatic switch off is on your kettle.

The Hob.

Just like with the kettle, use the minimum possible amount of water for boiling. Turn power to a gentle simmer as soon as boiling begins. Always boil with a lid on.

The Microwave Oven.

Many recipes say heat on full power for x minutes but full power is usually only needed to get up to boiling. After that a lower power can be used to complete cooking. As an example, for boiled potatoes for two (300 grams plus two tablespoons of water) in our 850 watt oven, we heat for 3.5 minutes on full, followed by 3.5minutes on low = 170 watts. To make porridge in a large bowl, 2 mins on high followed by stirring, then 30 seconds on high to restart boiling followed by 2.5 minutes on 350 watts. Or for a small bowl, 1 minute on high, stir, then 20 seconds on high followed by 2.5 minutes on low (170watts). It’ll no doubt be different for your oven so some experimenting is needed to find out how long it takes to get the porridge just to the boil. A big advantage of this method is that boiling over is avoided.

When using a slow cooker, we put a folded up towel on top of it to keep the heat in (same idea as loft insulation) but just on the top and a little way down down the sides. Do not completely cover the sides because the cables inside the casing could then get hotter than they should. We use the high setting (180 watts) to get the food hot. Ours will then cook on its lowest setting (60watts) which is intended for keeping food warm but with the insulation on the lid, temperature is maintained.

Laundry

Many washing powders work well at 20 degrees. Which magazine recommends Almat bio available form Aldi. Other top performers are Ariel All in One pods, Sainsburys Bio
Laundry Powder but these are more expensive per wash than Aldi Almat. Washing at 20 degrees makes a big saving compared to 30 or 40 degrees. For our machine, the “cottons 20 degrees” uses 0.3kWh, “cottons 40 degrees” uses 1.0kWh rising to 1.2 kWh at 60 degrees and 2.3kWh at 90. The machine should always be loaded to the recommended capacity because it uses the same amount of electricity whether it contains just one pair of socks or is full of socks. Filling it up gets the maximum cleaning for the electricity used.

Tumble driers should only be used if absolutely necessary. If possible, all washing should be dried outdoors where the energy needed to evaporate away the water is provided free of charge.

Washing up

If you have a modern dishwasher and fill it completely before washing, there’s not a lot in it between hand washing in hot water and using the dishwasher. However, its not necessary to use hot water for washing up by hand in which case washing up by hand saves quite a lot of electricity. For details see washing up in the heating section below.

Part 2. HEAT

As with electricity, there are a few actions which cost money and many more which depend on doing things differently.

General comments and additional help

The big wins are insulation, draught exclusion, thermostatic radiator valves (TRVs) and boiler upgrades if the boiler is old. Unfortunately, solid walls are expensive to insulate and free or low cost cavity wall insulation isn’t generally available direct from energy companies as it was a few years ago. However, there are funded schemes available but the qualifying criteria are complex. They depend on personal situations (eg universal credit or other benefits, energy rating of the property, etc ). Its worth contacting Act on Energy on 0800 988 2881 for free independent advice to see if you qualify. https://actonenergy.org.uk/

Loft insulation and draughtproofing windows and doors can be DIY if you are a DIYer, as can fitting TRVs if you are OK with plumbing. Loft insulation less than 100 mm thick definitely needs topping up.

Doing things differently to save on heating

As with electricity, there are quite a lot of these, some easier than others, some possible in some homes but not in others.

Cool zones.

Heat is only needed in places where people spend time. So, for these, such as kitchen or lounge, keep doors closed and turn heating down or off in hallways and landings where you only pass through quickly and in rooms that are not in general use such as spare bedrooms etc. However, if your system has only a single thermostat and it is in the hall, the hall must be heated otherwise the system will think more heat is required and some rooms will overheat.

As well as doors, windows should be kept closed as much as possible. Just like freezer and fridge doors, doors to outside and any cool zones should be closed as soon as possible after opening.

Heating can be turned off half an hour or maybe more before going to bed. People worry that turning off overnight results in additional fuel burn in the morning when the heating comes on. Its true that the heating system works hard during start up but the fuel saved by being off during the night is much greater than than the amount burned during start up so overall there is a substantial saving by switching off overnight.

Depending on the house, bedrooms and bathrooms may not need much heat except perhaps in very cold weather. If doors are kept closed, heat can leak upwards through the ceilings of rooms below.

Recommended temperatures and control.

If you do heat bedrooms, 16 deg C is a recommended maximum. For a room where time is spent seated/inactive such as the lounge, try 19 degrees unless you are over 60 where 21 degrees is recommended. To get good control, TRVs are really useful but as mentioned above fitting them is a job for a plumber or heating engineer unless you are happy with DIY plumbing. To check that temperatures are as recommended, a thermometer is required. Cardboard thermometers (officially known as heat cards) are sometimes available from doctors surgeries or form Act on Energy (no.above). In the lounge, measure the temperature at knee height or thereabouts. If you do not have a thermometer, a good starting point with TRVs is a setting of 3 for 21 degrees, two small divisions below 3 (=2.5) for 19 degrees and one small division below 2 for 16 degrees. However, valves do vary bit and draughts can alter the temperature actually achieved. Keeping doors closed reduces the impact of draughts. Adjusting TRVs should be done in small steps of about 1 small division = 1 degree or less followed by a pause to allow temperatures to settle down. A further advantage of TRVs is that they make it easy to turn radiators off. At bedtime we turn off our lounge radiators so that in the morning just the kitchen and study are heated. If we need the lounge to be warm after breakfast we put them on as soon as we come down stairs. On some days they do not get turned on until late afternoon thus creating significant savings.

Why is temperature control important? The higher the temperature inside a building, the faster heat leaks out, so more fuel has to be burned to keep the chosen temperature. Just 1 degree reduction in internal temperature reduces consumption by about 8%.

If you have a conservatory, open the door to the house on sunny days to import free solar heat.

Hot water

For homes with hot water tanks, additional insulation on the tank is important because the standard foam insulation (usually blue or green) is inadequate. Insulation jackets can be bought fairly cheaply and couple of these on top of the standard insulation is worth doing if space permits. All exposed pipes associated with the tank should also be insulated with pipe lags except for the cold feed pipe near the bottom of the tank which need only be insulated for about 300 mm. If the tank has the option of heating by immersion heater as well as from the central heating, make sure that the immersion heater is off – electrical heat costs approximately four times the cost of heat from gas.

Its easy to use the shower every day but for most of us not necessary. Every two or three days is usually OK unless you do heavy manual work. Keep showers brief. Baths use more hot water than showers so we have two per week. My wife leaves the water for me which, after letting a little out, can be topped up with more hot water. So we use a total of about 2.5 bathfulls a week between us which is equivalent to about 6 showers a week or one every other day for each of us. In the heating season we allow the bath to cool giving up its heat to the house before emptying the cold water down the drain in the morning. Hot water down the drain is money down the drain.

Washing up

Here’s a suggestion which might be controversial. Washing up can be done in cold water. Dirty plates are rinsed whilst giving a quick scrub with a brush to remove easily removable bits of food. Wet and then squeeze the water out of a non scratch scouring sponge and put two small drops of washing up liquid on the scouring surface. With the plate still wet rub it with the scouring sponge to generate a strong foam. This will cut through and release grease. Rinse away the foam under running cold water. A couple of drops of washing up liquid will last for several plates and when the foam weakens, another drop or two of washing up liquid replenishes it. This process avoids use of hot water which in our house is very wasteful because the tank is a long way from the kitchen. We have to run off a bowl full of water before the hot arrives. When we’ve got the hot water, there’s a long pipe full of hot water which then cools down. In summer, this is completely wasted because we do not need heat in the house.

A variation on the above is for frying and other pans where a small splash of cold water can be heated by the residual heat remaining in the pan. Add a drop of washing up liquid and brush to create foam in the now hot water. Finish with the scourer as above if necessary.