What is energy efficiency?
The term ‘energy efficiency’ is used a lot these days. Labels on appliances, advertisements from energy companies and even promises from the government all use the phrase, but what does it really mean?
Something is more energy efficient if it lasts longer or works better than a traditional version of the same appliance, but uses the same amount of energy. Or even if it delivers the same performance as the traditional version, but uses less energy.
Ultimately, energy efficiency means doing more with less: that is, squeezing as much useful power out of as little energy as possible, and not letting any go to waste. Take an old-style light bulb, for example. These bulbs produced light, but wasted a lot of heat in the process. New energy-saving light bulbs create the same amount of light without creating wasted heat, and they use less energy in the first place.
The same principle applies to all kinds of energy-saving appliances. An energy-efficient fridge will use less energy than an old model but still keep your food cool, while an energy-efficient washing machine will get your clothes smelling fresh and clean without using as much power as an older version.
The term energy efficiency can also be used in a wider sense. Instead of focusing on the energy efficiency of a single item (such as an appliance), we can also look at the energy efficiency of whole buildings. If two buildings are supplied with the same amount of energy to create heat, the building that can generate and retain the most heat – rather than only creating a little heat and then losing it – is the more energy-efficient building.
Read our complete guide to energy-saving bulbs and choose the right one to save money as well as cutting your carbon footprint.
Why do we need to be energy efficient?
Energy consumption has grown incredibly fast over the last few decades. We are in danger of using up the planet’s natural resources, of destroying vital habitats and polluting the air we need to breathe.
Energy efficiency is a way of managing and limiting this growth in energy consumption, to save wildlife habitats, safeguard the planet, and make sure there is energy left for future generations.
What do we mean by energy conservation, and what’s the definition of energy consumption?
Energy consumption is the amount of energy used up by a process, system or appliance – or by a country, person or business.
Energy conservation simply means using less energy, or even none at all.
Why is energy efficiency important?
Energy efficiency is playing an increasingly vital role in our lives, for three main reasons:
The more energy we use, the more carbon emissions are pumped into the atmosphere and the more our reserves of natural resources such as oil, coal and gas are depleted. We need to reduce our reliance on these energy sources, and one way to do that is to make sure we all use energy as efficiently as possible.
The global economy is based heavily on oil and gas, and as these resources dwindle their cost will increase, causing financial imbalances around the world and resulting in energy poverty in many areas of society.
Your bank balance!
Nobody wants to pay more than they have to for everyday necessities like heating and hot water, so it makes sense to be energy efficient. That way you fulfill your energy needs while paying as little as possible.
How can I be more energy efficient?
If you want to know how to be more energy efficient, the first place to start is to make sure your home and all your electrical appliances work as efficiently as possible. It isn’t energy efficient to throw out all your old products and replace them with new, energy-saving items; instead, wait until they wear out and then replace them.
Here are a few ideas to get you started:
Use less electricity
The first rule of saving electricity is: don’t leave appliances on standby. Of course you need to leave your fridge and freezer on full time, and maybe your alarm system – and you may need to leave the TV or satellite box on to record your favourite programmes. But for practically everything else electrical: when you’re not using them, switch them off at the wall.
Rechargeable batteries can also be a good choice. Just make sure you get top-quality ones that will last and hold their charge. You could also invest in a ‘smart charger’ that can prevent your batteries from overcharging.
If you want to make your laptop more energy efficient, you can get an Ecobutton. It plugs into a USB port, and flashes to remind you to press if you decide to stop using your computer for a while. It can then put your computer into its most efficient energy-saving mode. When you log on again, you can see on screen how much money and CO2 you’ve saved.
Switch to energy-saving light bulbs
Energy-efficient bulbs use up to 80% less electricity than traditional light bulbs and can keep going for ten times as long.
Just one energy-saving light bulb could save you approximately £2.50 per year – and this could rise to as much as £6 for brighter bulbs or any you leave on for several hours each day. So if you replace each of the standard bulbs in your home (when they stop working) with energy-saving bulbs, you could reduce your annual energy bill by as much as £37 and cut 135 kg of CO2 off your carbon footprint. That’s about the equivalent of taking a train from London to Glasgow and back, or using nearly 43 litres of petrol*.
Cut down the cost of heating your home
Hot water and heating make up around four-fifths of most fuel bills in the UK, so increasing the energy efficiency of your heating system can make a big difference to your utility bills.
If you’ve had your boiler for more than 15 years, it’s probably time to consider upgrading to a newer, more eco-friendly model. You could reduce your heating bills by up to a quarter if you replace a creaky old G-rated boiler with a new A-rated condensing boiler – as long as you use it wisely and control it effectively. Make sure your thermostat and boiler are communicating properly, fit individual thermostats on radiators, and get a control system that lets you switch off the heating remotely if necessary.
By the way, it's also a good idea to bleed your radiators once a year, so they're working as efficiently as possible. Find out how to do it, and why a yearly radiator bleed can bring your heating costs down, with our handy guide.
Insulate your roof and walls, install double glazing, stop draughts, update your heating system and take a bit more care about keeping doors and windows shut. You could also cut up to 10% off your heating bills if you lower your heating thermostat by 1°C and put on an extra jumper or fleece instead. There’s no need to have the thermostat on a hot water tank any higher than 60°C/140°F.
Think about other ways you might be able to heat your home more efficiently – like installing underfloor heating, which could be more efficient than traditional radiators, when combined with other efforts to make homes more efficient. Or, for something bolder, by building a Passive House – an amazingly energy efficient way of designing homes.
And finally, if you want to switch off your central heating and use a standalone heater to warm up just one room, check out our rundown of the most energy-efficient heaters.
Read our practical guide on smart thermostats and how they can help you control your heating from everywhere and reduce your energy bills.
*Mike Berners-Lee ‘How bad are bananas?’ Profile Books Ltd 2010