At the moment, it is not possible to store the electricity produced by renewable generators, such as wind and solar, on a nationalised scale so we need to use it there and then.
If it's a very windy or sunny day, lots of clean electricity might be produced, but if there's no demand for it, it can go to waste.
To encourage more people to plug in and use electricity when we have lots of green energy available, we have developed a new free app to show you in real time where your energy is being sourced from, how green it is and when the best time to use your electricity is.
It’s broken down by region too, so you can see how where you live compares to the rest of Britain.
What is carbon intensity?
When we talk about the carbon intensity of electricity, we are referring to the number of grams of carbon dioxide (CO2) that it takes to make one unit of electricity a kilowatt per hour (kW/hour).
When electricity is generated using coal power stations, the carbon intensity value is high as CO2 is produced as part of the power generation process.
Renewable forms of generation such as hydro or solar produce almost no emissions, so their carbon intensity is very low.
The lower the carbon intensity, the greener the electricity.
Carbon Intensity App
The Carbon Intensity App has been built in partnership with the WWF, Environmental Defense Fund Europe and the University of Oxford department of Computer Science.
Our Carbon Intensity app can be used by homeowners as a rough guide for when to charge your phone, put your washing on or run the hoover round.
It can also be linked to smart devices so you can automate your energy use to coincide with the peaks in green energy production.
Download the app and find out when the greenest hours each day, available on Google Play Store and The App Store.
What are the benefits of using electricity when it's cleanest?
There are lots of benefits to being smarter about when you use your energy.
Firstly, you are helping us to maximise the use of low carbon intensity electricity, which is helping us to reduce our carbon emissions.
Secondly, you could reduce your energy bills.
Renewable-powered generators cost money to build and maintain, but are relatively inexpensive to operate compared to traditional coal or gas-fired power stations, as they use solar and wind energy which is free.
This all helps to bring down the cost of making electricity.
Plus, if you are on a flexible time of use tariff, your provider may even pay you to use electricity (negative pricing) when there is too much power being generated by renewable supplies, and not enough demand to use it.
This ensures that our green electricity is not wasted.
Are there any other ways to reduce carbon intensity?
There are lots of ways that we can all do our bit to reduce carbon intensity.
Over the past five years we have reduced the average carbon intensity of our electricity system by 59% by getting less of our energy from traditional coal-fired power stations, and by helping more renewable generators connect to our electricity system.
You have also helped us to meet that target by using less electricity.
If you would like to make a difference to carbon intensity there are lots of things you can do.
3 ways to reduce carbon intensity
Swapping your old appliances for new more efficient ones
Insulating your house better
Investing in renewables for your own home such as fitting solar panels or a heat pump
For more information, visit carbonintensity.org.uk.