TRAGO Mills switched on what is claimed to be the largest single roof-mounted solar panel array in Northern Europe on Thursday morning.
The photovoltaic array was switched on at the family shopping and leisure park near Newton Abbot by Teignbridge District Council leader, Cllr Jeremy Christophers.
The project comprises an investment in excess of £2million.
The 3,754 panels will generate 778,862kWh of power to supply the store, with any excess energy going direct to the national grid to supply the local area.
The panels, which have a linear performance guaranteed over 25 years, were manufactured by SolarWorld which is based in Bonn, Germany.
The installation fell to local company Devon Eco Energy, which is a trading partner on site at Newton Abbot.
Trago is currently implementing similar, but smaller, installations at its Liskeard and Falmouth stores.
Trago chairman Bruce Robertson said: "With an electricity bill in excess of £250,000 per annum at the Newton Abbot site alone, it was imperative a solution was identified that provided substantial savings and certainty for the future.
"I am delighted by the unobtrusive roof installation, that in no way compromises or detracts from our well established design theme - no one would ever know it was there unless being told so."
The switch-on was also attended by Trago's group operations director Brent Pinhay and finance director Gary Lord, SolarWorld's UK brand development and country manager Scott McDaniel, and Devon Eco Energy directors Steve Frost and Ross Northcott.