Under the contract, npower will provide the retailer with 2.6 terawatt-hours (TWh) of wind and hydro electricity from April. That’s enough to power all of the retailer’s stores and offices in England and Wales.

The contract also allows for a significant amount of the supply to be purchased directly from independent small-scale generators of renewables. Marks & Spencer has pledged to purchase enough renewable electricity to power its entire UK portfolio of stores and offices.

From a 2006/07 baseline, the retailer has reduced its like-for-like electricity consumption by more than 6 percent and sourced more than 30 percent of its electricity from renewable sources.

In its 2007 corporate responsibility report, the retailer announced plans to make its UK and Republic of Ireland operations carbon neutral, landfill-free and sustainably sourced without passing on the extra cost to customers.

Marks & Spencer also has eco-factories in Sri Lanka and Wales that harness renewable-energy and recycling technologies.