Keir Starmer has pledged to create Britain's own state-owned power company to help slash the cost of bills if Labour wins power.
The Labour leader said that Great British Energy would boost the supply of renewable power by harnessing the country's sun, wind and waves.
The nationalised electricity generator, which will work alongside existing private firms, is aimed at bringing down prices for families as well as delivering energy independence for Britain.
He said: "A new company that takes advantage of the opportunities in clean British power and because it's right for jobs, because it's right for growth, because it's right for energy independence from tyrants like Putin.
"Yes conference, Great British Energy will be publicly owned."
Labour highlighted that many European, Asian and American countries have public generating companies, including EDF in France and Vattenfall in Sweden.
It builds on Labour's commitment to make the UK a clean energy superpower by 2030 and create a National Wealth Fund.
The commitment came in his keynote speech to the Labour conference in Liverpool in which he declared he is ready to boot the Tories out of No10.
He told delegates a "cloud of anxiety" hangs over the public and accused the Tories under Liz Truss of crashing the pound and offering tax cuts for the richest 1% in society.
Mr Starmer added: "They used to lecture us about fixing the roof when the sun was shining. They haven't just failed to fix the roof.
"They've ripped out the foundations, smashed through the windows and now they've blown the doors off for good measure."
The Labour leader also received a standing ovation during the speech when he pledged to make the Labour Party "fit to serve our country".
"That's why we had to rip antisemitism out by its roots. Why we had to show our support for NATO is non-negotiable. Show we want business to prosper. Shed unworkable policies. Country first, party second".
Mr Starmer also led a chant of "Slava Ukraini" - Glory to Ukraine - after pledging to never allow Russian President Vladimir Putin's "threats and imperialism to succeed".
He told delegates one of his first acts if he wins the keys to No10 would be to create a Hillsborough Law - to hold public bodies accountable following tragedies.
“For too long this city has been let down," he said. "So when Labour wins the next election, one of my first acts as Prime Minister will be to put the Hillsborough Law on the statute book.”
Concluding his speech on Tuesday, the Labour leader said there would be "no deal under any circumstances" with the SNP and promised to "deliver change" in Scotland.
He added: "We need to be prepared, disciplined, focused. Spend each day working to earn the trust of the British people.
"Meet their attacks with hope. Provide the leadership this country so desperately needs. Because as in 1945, 1964, 1997, this is a Labour moment.
"So, conference, say it loud and believe it. Britain will deal with the cost-of-living crisis. Britain will get its future back".
Labour said Great British Energy would be 100% owned by the state.
It would focus only on power generation - not replace retail firms like British Gas or Scottish Power - and not nationalise existing firms.
The firm would get seed funding from a £8.3bn, 10-year National Wealth Fund before becoming self-reliant as it grows, officials hope.
It could invest in experimental projects like tidal power or floating offshore wind.
But the firm would make its own decisions on investment rather than having them dictated by Labour ministers.
Labour officials said the ambition would be for GBE to export power to other nations. Extra revenues would go back to the public purse.
