John Swinney has proposed a new "social tariff" to help the elderly, disabled and those on low incomes with their energy bills.
The SNP leader said the new plans would be paid for through "top slicing the profits of energy companies" as well as general taxation.
The party said the amount that energy companies would contribute would be set through negotiations.
The total cost of the policy would have been about £7.8bn for the current year.
Mr Swinney said the tariff, which would also help with broadband and mobile charges, is a "good starting point".
Speaking in the Western Isles, he added: "So at the heart of our manifesto will be that commitment that we will argue for the delivery of a social tariff, funded by general taxation and by the power companies, which will reduce the costs for those who are vulnerable in our society and give them a material contribution to reducing the cost of living.
"But we've also got to make sure that addresses all the requirements of people for their connection with society.
"Today, none of us really can operate without connectivity. Access to broadband and access to telecoms. So many public services are delivered by that mechanism as well.
"So we're going to propose that the social tariff extends also to broadband and telecoms costs so that people are liberated of the excessive burden and they're able to access public services and they're able to access wider communications in society because they have got a tariff that is appropriate for meeting their circumstances."
The First Minister also compared the likes of mobile phones to basic utilities such as the NHS and schools.
He continued: "We believe that there are certain things that every citizen should have access to as a right. Healthcare free at the point of need, a social security safety net, pensions for older people, and free education including free university tuition.
"But it is time that we recognised that these rights need to go further, to reflect the realities of the modern world.
"Connectivity – fast broadband and good mobile phone connections – are critical to modern life. In fact, in rural Scotland and the Isles, it is critical to the whole future of the economy.
"As more and more people work from home at least part of the week, often you literally cannot do your job without a decent internet connection. That’s why, to help people get jobs, keep jobs and keep more of their hard-earned cash, there should be a social tariff for broadband and mobile charges too."