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Clean energy gets the green light - literally!

National Grid has launched a new bulb which lights green to show people the cleanest times to use electricity.

The company believes there is an ‘awareness gap’, with most members of the public not knowing how much of the UK’s electricity comes from low carbon sources such as wind, solar and nuclear.

Its research indicates that 42% of people believe a maximum of 10% of the country’s electricity comes from from zero and low carbon energy sources. In reality around 55% of our electricity is ‘green’.

But unfortunately there is another complication. The disadvantage of many renewable sources is that their supply of electricity varies – depending on how windy it is or when the sun is shining.

And when demand is very high (perhaps on a cold day, or when we all put the kettle on), it might be necessary for extra reserve power stations (usually burning gas) to come online – great for keeping the lights on, but not in terms of carbon emissions.

These things means that our exact ‘electricity mix’ is always changing – sometimes the proportion of green electricity sources is higher, sometime it’s lower.

And that’s the inspiration behind National Grid’s ‘Green Light Signal’.

The Green Light Signal

The Green Light Signal is essentially a smart light bulb designed to glow green when the electricity supply is on the cleaner end of the scale, meaning people can choose those times to use electricity.

The clever gadget is powered by National Grid’s carbon intensity tool,, built by National Grid ESO, WWF and The University of Oxford and The European Defence Fund.

John Pettigrew, Chief Executive of National Grid, said:

“We know there is still lots to do, but by showing people the progress that’s been made and bringing them together to better understand energy consumption with tools like the Green Light Signal, collectively we can make a real and significant impact in the fight against climate change.”

While undoubtedly a positive idea which may help cut carbon emissions, National Grid may have an extra motive too. If people can be encouraged to use electricity when there’s lots available (usually when wind conditions are perfect or when the sun is out), and save it when there’s less, supply and demand can be balanced, leading to a more efficient system.

Stock of the Green Light Signal seems to be limited at present, but smart lighting company LIFX will be the place to grab one. Many early adopters are already experimenting with how to create a stylish feature of the light in their homes, and we’ll certainly be giving it a go when we get hold of one!

What uses the most electricity?

It’s great if we know when our electricity is at its greenest. But which household activities should we alter to make the most of this?

There are some times when we won’t have much choice – the fridge can’t just be turned on and off whenever we feel like it! And actually many activities – such as turning on the lights and charging our phones – use very little electricity at all.

It’s best to focus on the large appliances where timing can be flexible. Tumble dryers and washing machines (especially on high temperature settings) can be energy-hungry, while it definitely makes sense to charge electric cars and bikes when our electricity is at its greenest.



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