Image copyright PA Image caption The UK's first subsidy free solar farm at Flitwick in Bedfordshire also opened on Tuesday

More than half the UK's electricity came from low carbon sources this summer, the National Grid says, making it the "greenest" summer on record.

Between late June and September, 52% of electricity generation was met by low carbon sources, compared with about 35% four years ago.

The Grid has launched software that forecasts the carbon intensity of electricity up to two days ahead.

It hopes this will help people to understand and control energy use.

Shifting the timing of activities such as running a dishwasher or charging electric vehicles could help relieve pressure on the energy system, reduce the need to use back-up fossil fuel plants, and potentially reduce bills for households.

The software combines National Grid's knowledge of the energy system with weather data from the Met Office to forecast the share of renewable and non-renewable energy on the grid over the next 48 hours and the resulting carbon emissions.

It is hoped that technology companies will then develop apps and software that could help people control when and what type of energy they use.

Duncan Burt, from National Grid, said: "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."

'Landmark development'

Meanwhile, the UK's first subsidy-free solar farm was officially opened on Tuesday.

The 10 megawatt Clayhill solar farm, near Flitwick in Bedfordshire, will generate enough electricity for around 2,500 homes and save 4,452 tonnes of carbon.

In addition to the rows of panels there are five battery storage units, to maximise use of power from the solar farm by allowing electricity to be stored and fed into the grid when it is needed.

Steve Shine, executive chairman of Clayhill's developer Anesco, said: "For the solar industry, Clayhill is a landmark development and paves the way for a sustainable future, where subsidies are no longer needed or relied upon."