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26 September 2017

National Grid confirms summer 2017 as “greenest ever” and launches “world’s first” green energy forecast.


While the end of summer may have meant grey weekends for some, it was in fact the ‘greenest’ summer on record according to new data from National Grid.

From 21 June to 22 September, almost 52% percent of our electricity generation was met by low carbon sources, compared to around 35% four years ago. This news comes as the company today launches innovative new software that forecasts the carbon intensity of electricity generation up to two days ahead, helping people to understand and control their energy use.

National Grid is working with Environmental Defense Fund Europe and WWF to make the software openly available to the public. WWF has used the data as the basis of an online tool which points users to the best times to turn on or turn off home appliances to minimise carbon emissions, while Environmental Defense Fund Europe are working on policy implications of having this data available and widely understood. Shifting activities like dishwasher cycles or electric vehicle charges could help relieve pressure on the energy system, reduce the need to use back-up fossil fuel plants, and potentially reduce bills for households.


Duncan Burt, Director of the System Operator at National Grid, said:

“We're providing our forecast data in a format that allows technology companies to build innovative apps and software that could make a real difference to how and when people use energy. Clear and concise information that can tell you in advance when’s best to turn on the washing machine, load the dishwasher or charge your car for example, is a step in the right direction towards a low carbon future. This technology puts people at the heart of it, helping everyone to use power when it’s greenest, and likely, more cost efficient”.

“It’s been an exciting year managing the many ‘network firsts’ - from a day where we operated the system with zero coal power, to one where over half of Great Britain’s energy demand was met by renewable generation -and we’re just as excited to see what developments come off the back of making this data available for all”.


The programming software combines National Grid’s deep knowledge of the UK energy system with weather data from the Met Office to forecast the share of renewable and non-renewable energy that will be on the UK electricity grid over the next 48 hours, and the resulting carbon emissions. National Grid’s data has been verified by experts from Oxford University.


Gareth Redmond-King, Head of Climate & Energy at WWF, said:

“How electricity reaches our homes is often out of sight - we just flip the switch and pay our bills. But the changes to our electricity system are opening up more choices for consumers. Green energy forecasting could be a game changer – making the connection between the weather and energy and helping people use electricity when it’s greenest. This is not just good news for reducing the effects of climate change but could also help us cut our home energy bills and it’s vital the UK Government bring in time of use tariffs quickly to maximise these opportunities.”


This is the first time that carbon intensity data has been modelled to provide an accurate forecast for future carbon intensity. All partners in the project have agreed to make the software, known as an application programming interface (API data) available so that tech developers can create consumer friendly applications.


Bryony Worthington, Executive Director, Environmental Defense Fund Europe, said:

“This new forecasting tool empowers businesses and people with information they need to make cleaner energy choices. We are calling on those operating in the electricity market, including suppliers, manufacturers, aggregators, regulators and policymakers, to take advantage of this innovative, free-to-use tool to deliver smart, resilient infrastructure that cuts pollution, boosts renewables and unlocks costs savings for consumers. Pioneering practical tools that work for people, business and the environment here in the UK will serve as a model for other countries looking to meet bold climate and energy goals.”


Professor Alex Rogers at Oxford University, added:

"We released the Grid Carbon app in 2010 to enable individuals to monitor the carbon intensity of the grid in real-time and it has been heartening to see carbon intensity decrease steadily over time. It's fantastic news that National Grid will now be providing authoritative predictions of carbon intensity through a robust API. I'm really looking forward to seeing how this new information will be exploited in new apps and services."


Gareth Redmond-King, Head of Climate & Energy at WWF, concludes:

“Today’s announcement by the National Grid is a great leap forward in the transformation of our energy system from fossil fuels to renewable energy. As we begin to feel the winter chill roll in, it is warming to know that the renewables industry is getting big projects built and slashing its costs. But now it’s time for the UK Government to step up and deliver a strong and ambitious clean growth plan, continuing to support renewables, cleaning up our transport and making our homes more energy efficient”.





Media Contacts:

National Grid

Gemma Stokes

Corporate Media Relations Manager
O:+44 (0)1926 655272
M:+ 44 (0)7974 198 333


Environmental Defense Fund Europe

Baroness Bryony Worthington

Executive Director

Tel: 07876 130 352



Jonathan Jones

Press Officer

Tel: 01483412241


Notes to Editors:

National Grid’s carbon intensity forecast can be viewed here: (The API can also be accessed as well as the applied methodology to forecast carbon intensity)

If you want to make a green cup of tea, check out our forecast to find the greenest time of day to pop the kettle on.


Summer 2017 facts

National Grid is in a new era of network operation and has seen a number of firsts this year;

  • In April, we had the first working day since the start of the industrial revolution where UK electricity supplies were met without the need for coal generation.
  • On 31 May, a record was set when a quarter of Great Britain’s energy demand was met by the seven gigawatts of solar power that was supplying electricity to the grid,
  • On 7 June, renewable power met over 50% of the nation’s electricity supply. Days later, large amounts of wind, solar, and nuclear power pushed Great Britain’s carbon intensity to record lows of around 90 gCO/kWh.

National Grid

National Grid is one of the largest investor-owned energy companies in the world. We own and manage the grids that connect people to the energy they need, from whatever the source. In Britain, we run the gas and electricity systems that our society is built on, delivering gas and electricity across the country. In the North Eastern US, we connect more than seven million gas and electric customers to vital energy sources, essential for our modern lifestyles.

National Grid in the UK:

  • We own the high-voltage electricity transmission network in England and Wales, operating it across Great Britain
  • We own and operate the high pressure gas transmission system in Britain
  • We also own a number of related businesses including LNG importation, land remediation and metering
  • Our portfolio of other businesses is mainly concerned with infrastructure provision and related services where we can exploit our core skills and assets to create value. These businesses operate in areas such as Metering, Grain LNG Import, Interconnectors and Property. National Grid Carbon Ltd is a wholly owned subsidiary of National Grid. It undertakes Carbon Capture Storage related activities on behalf of National Grid.

National Grid in the US:

• National Grid delivers electricity to approximately 3.4 million customers in New England and upstate New York

• We own 3.8 gigawatts of contracted electricity generation, providing power to over one million LIPA customers

• We are the largest distributor of natural gas in northeastern U.S., serving approximately 3.5 million customers in New York, Massachusetts and Rhode Island.

Find out more about the energy challenge and how National Grid is helping find solutions to some of the challenges we face at


WWF is one of the world’s largest independent conservation organisations, with more than five million supporters and a global network active in more than one hundred countries. Through our engagement with the public, businesses and government, we focus on safeguarding the natural world, creating solutions to the most serious environmental issues facing our planet, so that people and nature thrive. Find out more about our work, past and present at

Environmental Defense Fund Europe ( is a charity focused on finding the ways that work to address the most world’s most serious environmental problems, using science, economics, law and innovative private-sector partnerships. Read our strategic plan at and connect with us on Twitter @EnvDefenseEuro.