It will be run in conjunction with Community Service Volunteers (CSV), National Energy Action and Energy Action Scotland.
CSV head of press Jason Tanner said: 'As Exxon is prepared to give us the resources to do this, two things will follow: a number of people will get their homes insulated to reduce their expenditure on fuel; and our innovative, cost-effective approach will build a pathway for others to follow.
'The Energy Challenge also helps to demonstrate the positive contribution that older people can make to their communities.'
Tanner added that CSV has had an ongoing CSR relationship with Exxon since 1984. The world's largest oil and gas group has come
under fire for posting massive profits by green groups, which have accused it of showing insufficient regard for the environment. The firm made a record £20bn profit in 2005.
It is keen to counteract criticism by highlighting its environmental and social work – in the UK Exxon says it spends £2.7m a year on CSR projects.
UK head of media relations David Eglinton said: 'Regrettably we believe that Exxon Mobil's view on global climate change has been misrepresented or misunderstood. Exxon is taking action to address the risks.'
The Energy Challenge is being monitored by corporate responsibility consultancy The Smart Company.
The scheme will run until 2007 across eight London boroughs and in Scotland before a national launch.
According to Exxon, three million households in the UK are in fuel poverty.