Inenco, M&Ss energy consultant, deal with the agreement which will begin from April 2010 for four years.
The contract signing is a big step towards achieving its Plan A objective to source or generate 100 per cent green energy for all M&S stores, offices and distribution services in the UK and Ireland.
Although it has not yet been finalised which specific plants will provide the electricity, there is a number of energy from waste and biogas plants among them but all renwable energy facilities are situated in Scotland.
M&S head of energy management Mervyn Bowden said: Sourcing our electricity from independent renewable generation is an important part of our wider commitment to the environment through Plan A, our 100 point eco-plan. SmartestEnergy was the only supplier that provided this arrangement supporting the local renewable generation sector, and we are delighted to be working with them under this exciting contract.
SmartestEnergy allows business customers to specify the exact generation project they want their renewable electricity to be sourced from, unlike other energy firms. The only Scottish M&S venue not to receive SmartestEnergy power is the Pollock store, which is supplied by Npower.
SmartestEnergy vice president Jo Butlin said: If we want to meet our renewable energy and climate change targets it is essential that we support independent generators who are fundamental in helping us bridge the forthcoming energy gap in a cost-effective and environmentally-responsible way. Corporate demand can help support these generators and Marks and Spencer is leading the way.
Over 3000 business sites have signed up to buy 100 per cent renewable electricity from the firm since launching over a year ago. Customers include the Arcadia Group, Eurostar, LOreal and Lloyds Pharmacy.