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The Carbon Mission
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Light up for less

Lighting is one of the easiest places to start. Each step takes a few minutes, and you can do them in any order.

Where do you live?

Your wins so far

0 of 3 wins ticked off

Money saved
£0.00
a year off your bill
Carbon saved
0.0 kg
a year kept out of the air

Tick off each win as you do it and watch your savings grow.

  1. Step 1: Swap old bulbs for LEDs

    LED bulbs (the modern kind, made of tiny light-emitting diodes) give the same light for far fewer watts. Start with the lights you use most.

    Good to know: Bulbs that earn the ENERGY STAR label use up to 90% less energy than standard bulbs. Source: ENERGY STAR, low- to no-cost tips for saving energy at home.

    watts

    Printed on the bulb, next to a W. We have started you on a 60 watt bulb.

    watts

    Printed on the LED's box. We have started you on a 9 watt LED; yours may differ.

    bulbs

    Count the bulbs you are changing.

    hours a day

    A rough guess is fine.

    Money this saves
    £58.79
    a year off your bill
    Carbon this saves
    32.2 kg
    a year kept out of the air

  2. Step 2: Switch off lights in empty rooms

    A light in an empty room helps nobody. Make a game of it: last one out flicks the switch.

    watts

    Printed on the bulb, next to a W.

    bulbs

    Count the bulbs in the rooms nobody is in.

    hours a day

    The time each day they used to light an empty room.

    Money this saves
    £3.46
    a year off your bill
    Carbon this saves
    1.9 kg
    a year kept out of the air

  3. Step 3: Use a lamp instead of the big light

    Reading or watching TV? One lamp near you often does the job of a whole ceiling of bulbs, and feels cosier too.

    watts

    Add up the watts of every bulb in it.

    watts

    Printed on the lamp's bulb, next to a W.

    hours a day

    A rough guess is fine.

    Fill in every box with your own numbers, and the money and carbon this saves will appear here.

How we worked it out

For lights and devices: watts saved × how many × hours a day × 365 days ÷ 1,000 gives the kWh (kilowatt-hours, the units on your bill) saved in a year. For washing and drying: kWh for one load × loads a week × 52 weeks. We multiply the kWh by the price of one kWh for the money, and by the carbon released per kWh for the carbon.

  • Price: Ofgem, energy price cap for 1 October to 31 December 2026: 26.32p per kWh (paying by Direct Debit, average for England, Scotland and Wales).
  • Carbon: Department for Energy Security and Net Zero, greenhouse gas conversion factors 2026: 0.144 kg per kWh (0.131 for generating UK electricity plus 0.013 lost on the way to your home), counting carbon dioxide and the other greenhouse gases together.

The numbers in the boxes are yours to change, and your savings are only as exact as they are. Where a box starts on a number, it is only a starting point. Your progress is kept in this browser only.