Green Light Signal Downing Street - Boris Johnson

Green light signals clean energy at 10 Downing Street

10 Downing Street’s famous door is being lit up in celebration of the UK hosting the COP26 Climate Conference, of which National Grid is a principal partner.

As part of our Green Light Signal initiative, Number 10 will shine green to highlight the country’s shift towards cleaner, greener energy.

From 28 October to 5 November 2021, the entrance to one of the country’s most important addresses will play a part in highlighting the UK as a leader in the energy transition.

The archway of green lights will symbolise the cleaner energy powering Glasgow, where COP26 is taking place, and is accompanied by real-time carbon intensity data displays for the region of South Glasgow.

I’m delighted to see Downing Street glowing green to mark our progress towards achieving a clean and reliable electricity system.

– Boris Johnson

Prime Minister Boris Johnson said: “With COP26 just a few days away, I’m delighted to see Downing Street glowing green to mark our progress towards achieving a clean and reliable electricity system – supplying towns and cities across the country.

“We can all do our bit to reach net zero carbon emissions, and the National Grid’s fantastic new app will help consumers power their homes and appliances with green, clean energy.”


What is the Green Light Signal?

Our Downing Street installation is inspired by the Green Light Signal – a low-energy light bulb that glows green when the electricity supply is cleanest.

The special Green Light Signal bulbs let you know when the electricity in your area is being supplied mainly from low-carbon sources, such as wind or solar. At these times, you can use electricity knowing that it’s coming from sources that are cleaner and greener.


How to know when your home is being powered by cleaner electricity?

There are now ways to find out when renewable and/or nuclear energy will play a bigger part in the electricity supplying your home, so you can make sure you’re plugging in at the best times for our planet.


1. Download the WhenToPlugIn mobile app

The WhenToPlugIn app forecasts the times of low carbon intensity in your region, so you can plan your electricity use for the ‘greenest’ times of day and save those energy intensive tasks for when they’ll have the least impact on the environment.



2. Ask your Amazon Alexa or Google Assistant for the best times to use your electricals

With the National Grid digital voice assistant skill, your voice assistant will let you know when the electricity in your area will be cleanest over the next 48 hours, so you can make the most of those times when carbon intensity is low.



3. Get your very own Green Light Signal bulb

If it’s good enough for the Prime Minister...! The Green Light Signal bulb can be used with any standard table or floor lamp and will glow green when the electricity in your local area starts to be supplied mainly from clean or green energy sources, such as wind or solar.


John Pettigrew, CEO of National Grid, says: “Climate change is the biggest challenge of our time. At a moment when world leaders, businesses and campaigners are in the UK for COP26, we are proud to show just how much greener, cleaner energy is powering Glasgow.

“Overall Great Britain’s energy system is becoming greener – in the last seven years we have cut carbon emissions from the electricity system by 66 per cent with clean energy like wind, solar and nuclear accounting for an average of 55 per cent of Britain’s electricity mix.

“By arming consumers with the facts about when their electricity is cleanest, we can show how every small action makes a difference to our planet.”

The installation will continue to light up Number 10 Downing Street until 5 November, after which it will be relocated to one of National Grid's UK offices.