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Earth Hour and low carbon lighting

Hands painted with blue green of the planet forming a heart with Earth Hour written inside

What is Earth Hour?

Astronauts in the International Space Station may notice the earth seems a little dimmer on March 28. Some will hope they see a complete blackout.

That Saturday evening marks the annual WWF Earth Hour. Millions of people will turn off their lights at 20:30 local time, to draw attention to climate change, food waste and many more environmental issues.

The Empire State Building, the Eiffel Tower and the Sydney Opera House are among more then 18,000 iconic buildings across 180-plus countries that will part in Earth Hour

Organisers hope these global gestures will increase pressure for action at three key United Nations (UN) policy-making meetings later in the year; sustainable development in July, climate change in November and biological diversity in October, always presuming these will go ahead.

Find out more about #ForPeopleForPlanet and a decade of action.

What has Earth Hour achieved?

Earth Hour has taken the climate emergency conversation from conferences to mainstream thinking, as well as:

  • Created a 3.5 million hectare marine-protected area in Argentina
  • Established a 2,700-hectare protected forest in Uganda
  • Helped pass new legislation for the protection of seas and forests in Russia.
  • Initiated the planting of 20,000 mangrove seedlings in 13 cities in Indonesia.

How lighting can achieve more

With Earth Hour in mind, Energy Saving Trust is encouraging people to put their daily home and business lighting use under the spotlight.

The typical UK household has around 33 light bulbs, accounting for around 15% of your electricity bill. By using effective lighting controls (switching off unused lights) and energy efficient lighting (LEDs), lighting could drop to around 4-6% of the UK’s total electricity use.

Always turn the lights off

The quickest way to start saving is just remembering to turn lights off when you don’t need them. The typical household could save almost £15 a year just by switching off the lights as you leave the room, with greater savings still if you use energy efficient bulbs.

Changing to LED bulbs

Close up of man changing bulb to an LED lightbulb

Switching from traditional halogen bulbs to a similarly bright LED can save you up to £3 per year per bulb, equivalent to around 5kg of CO2 emissions.

By replacing all bulbs in your home with LED alternatives, you could save about £39 a year on your electricity bills, around 63kg of CO2 emissions.

If all 28 million homes in Britain switched to 100% LED bulbs, we could save 1.7 million tonnes of CO2 emissions annually.

CFLs, LEDs and traditional bulbs

Compact Fluorescent Lamps (CFLs) were the first energy efficient bulbs on the market and are around 80% more efficient at producing light than traditional incandescent bulbs.

But now they have been largely surpassed by LEDs, which are more efficient still, turn on instantly at full brightness, and are available to fit pretty much any light fitting in the home. They also last even longer than CFLs, and now the cost of the bulbs has come down they will definitely save you more money in the long run.

LED performance

A good LED bulb should last between 15-25 years (15,000-25,000 hours) based on average use of being switched on for about 2.7 hours per day.

Different bulbs emit a different colour of light - it can vary from a warm yellow colour to the bluish-white colour of bright daylight.  Colour temperature is measured in Kelvin (K) and you just need to select the right bulb.

  • If you want a room to feel warm and cosy (bedroom or sitting room) - look for an LED bulb that’s 2,700K.
  • If you want a room to look bright and sleek (bathroom or kitchen), choose a 4,000K bulb.

More lighting energy saving tips 

  • Always turn lights off when leaving a room, regardless of how long for.
  • Be conscious of how many lights you have on and whether they all need to be in use.
  • Arrange light switches so that it’s convenient to turn them off e.g. place switches at top and bottom of stairs, each end of a hallway and each door to a room.
  • Use a sensor and timer on external lights so they are only in use when they need to be.
  • Use appropriate lightings e.g. a low background light while watching television and a bright, concentrated light for reading. Having a range of lights in a room with separate switches will make this easier.

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Tom Shearman's picture
Tom Shearman brings 25 years' of journalism experience to the Energy Saving Trust blogging team. He loves writing about renewables and energy efficiency, plus how policy can change people and the environment. His articles have been published internationally, he has co-written trekking guide books, responsible travel articles and short stories.