Solar power is set to supply 15% of the UK's electricity needs early this afternoon, the industry said as its annual open day scheme begins.
As the UK basks in a heatwave, solar-powered homes, commercial rooftop schemes and solar farms will be open to the public today and tomorrow as part of "solar independence day".
Locations ranging from a housing estate in Northumberland, a stately home in Aberdeenshire, a community-owned solar farm and a waste facility in Berkshire will be showing off their clean power installations.
The solar industry, whose analysis predicts the technology will be supplying 15% of UK power demand at 2pm today, has set out how it believes the Government can double the amount of solar and make it as cheap as fossil fuel electricity by 2020.
An ambitious programme to deliver two million homes with solar power, 24,000 commercial rooftops and 2,000 solar farms by 2020 and providing 56,900 jobs would cost around £13.35 on the average consumer energy bill by the end of the decade.
Though it would cost £350 million more than the Government's planned spending of just under £1.2 billion in 2020, it would deliver around twice as much solar capacity as current policies and would lead to solar being free of subsidies, the industry argues.
The latest statistics show that there are more than 709,000 solar installations around the country.
While solar panels are an intermittent source of power, a new generation of batteries - which home owners could install in their homes - will allow them store the electricity they generate from the sun for use in the evenings.
Paul Barwell, chief executive of the Solar Trade Association, said: "It's great to see so many solar home owners and businesses get involved in solar independence day, showing how solar really gives power back to the people, allowing households and businesses to generate their own clean, green electricity.
"At more than 80% public support, solar has been shown in government opinion polls to be the country's most popular form of energy."
Energy Minister Andrea Leadsom said: "Solar is an integral part of the UK's energy mix. It's great to see industry initiatives like this boosting confidence and take-up, so hardworking families and businesses can benefit from low-carbon energy and lower bills."
Renewable electricity supplier Good Energy has opened the gates of its solar farm near Bude in Cornwall to the local community.
Chief executive Juliet Davenport said: "Solar power in the UK is an astonishing success story. Five years ago solar hardly existed in the UK, so it's amazing to see that today over 15% of the UK's electricity is produced by solar.
"The public has really got behind it, it goes hand in hand with farming and biodiversity, and best of all it doesn't pump carbon into the atmosphere."