Marks & Spencer will install the largest commercial rooftop solar system in the UK at its East Midlands Distribution Centre in Castle Donington.

Power from the 6.1MW array, expected to be online early next year, will be bought exclusively by M&S through a 20-year power purchase agreement. The facility will be close to self sufficiency during the day, according to Amber Infrastructure, which is developing the array.

“This further enhances the sustainability credentials of our BREEAM Excellent Castle Donington site,” said Hugo Adams, director of property, M&S. “Coupled with one of Europe’s largest solar thermal walls, the new solar PV system will make the building one of the most sustainable distribution centres in the world,” he added.

Amber Infrastructure will fund and supply the system, which was designed by SBC Renewables. It will be constructed by the Mark Group.

The array will also include a single cantilever mounting system to boost its output.

“M&S’s Plan A commitment is industry leading,” said Tom O’Shaughnessy, Partner at Amber Infrastructure. “We believe the unique structure of this project will create a template for the delivery of similar schemes across the UK supporting the stated objectives of DECC and wider UK Government. We look forward to revealing the finished array in 2015.”

M&S joins a number of other big brands that making use of solar including BT, BMW and Sainsbury’s.

M&S has a major sustaianability drive, Plan A, spanning its procurement, logistics and real estate.

A report released on Wednesday found that installing solar can boost the value of commercial property.