The supermarkets are trumping each other with state-of-the-art eco stores that cut energy bills and collect rainwater. But is the boom really just about a green image, asks Ian Quinn

Like a retail version of the hit TV show Grand Designs, supermarkets are pushing the envelope when it comes to store design and the green agenda - but for old-fashioned reasons: cold hard cash.

A report published by the Carbon Trust underlines the key attraction of going down the eco-store route. It claims retailers who invest in renewable energy in their stores could slash their energy bills by more than 20% some incentive when you consider that energy prices are predicted to skyrocket by as much as 37% by 2020.

“Before it was a moral agenda and it was a green agenda. Now it’s a financial agenda,” explains Ivan McKeever, director at WEMS International.

McKeever’s company is one of a growing number of environmental companies working with retailers to come up with the next big breakthrough in green store design, as each time a retailer ups the ante, a rival follows suit. This sort of healthy competition has put the supermarkets streets ahead of other retail sectors. “The reality is that food retailers are at the leading edge of industry energy management,” claims McKeever.

Many of the most mindblowing eco innovations are taking place at hypermarket style stores. Tesco, committed to becoming a carbon-neutral company by 2050, issued its latest statement of intent last year with the launch of the world’s first zero-carbon store, in Ramsay, Cambridgeshire. It’s since opened two more following the same blueprint.

The timber-framed unit uses skylights and sun pipes to slash lighting cost, and rainwater collection to flush the toilets and run the carwash. The store has also tackled the thorny issue of refrigerators by putting doors on them and taking out harmful HFC refrigerant gases. Tesco is so confident that its green innovations are potential game changers, the retailer is even offering customers eco-store tours so they can see how the cutting-edge technology works for themselves.

The new generation of green superstores are part of an evolution in design that started in the 1990s. And though Sainsbury’s first eco-store opened to a fanfare of publicity just over a decade ago, the technology it’s using in its latest green stores is light years ahead. The best example of this is the retailer’s use of geothermal bore holes to heat and cool stores.

Pioneered in Crayford and due to be rolled out in six stores this year and 20 next, the technology, which has been developed thanks to a pioneering tie-up with an oil company, tackles the problem of energy waste in a genuinely pioneering way. Instead of the heat generated from the refrigerated units travelling to the top of the stores, it is channelled via heat and air 500m below ground in a series of small tunnels a quarter of a mile apart, which simultaneously heat and cool the stores.

And Sainsbury’s has entire teams of scientists currently working across its portfolio of stores, both old and new, checking to see whether or not the ground is suitable for the installation of this system. This is more than just about creating eco trophy stores, says Sainsbury’s director of store development David Sheehan. There’s also a financial imperative involved.

“We are making our stores greener because our customers expect us to, but every time it is also because there is a commercial reason,” he explains.

Finding out what works
But just because the figures stack up it doesn’t mean something is guaranteed to work. Sainsbury’s hatched a cunning plan to generate energy for its stores using the traffic driving into its car parks, only for the equipment to break under the strain.

As this example underlines, it’s very much a case of trial and error when it comes to eco innovations. “All retailers are trying to do different things and they are testing all sorts of stuff but they are also hitting barriers,” explains Rob Sargent, director of retail at Stride Treglown Architects.

He cites the example of the German idea PassivHaus, which is being touted by many as the future of eco-stores. The concept allows buildings to make dramatic savings in energy because they are made of wood and, as near as possible, are airtight. But even this has its flaws as air can escape from the building as customers come in and out through the front door. It adds fuel to Sargent’s theory that there isn’t going to be a “big nirvana moment” any day soon.

“I think it will be a combination of finding out what works and what doesn’t,” he predicts. “It will be an evolution rather than a revolution.”

The Co-operative Group (The Strand, London)

It’s estimated just 30% of the 10,000 or so convenience stores in the UK are fitted with energy management systems, but The Co-op says its shiny new store on The Strand, in London, is an exception. Launched in February 2011, the retailer claims the store is the first c-store in the country with 100% LED lighting this includes all fridges, freezers and external signage.

Marks & Spencer (Stratford, London)

The new Stratford store is its most carbon-efficient to date, claims M&S some 30% more efficient than a similar store and is on course to achieve a BREEAM rating of ‘excellent’. In addition to the green ‘living roof’, which provides natural insulation and encourages biodiversity, 100% of the store’s heating and hot water and 99.5% of cooling will be provided by the on-site power plant. 

Sainsbury’s (Dawlish, Devon)

The store was built like a giant DIY kit and is influenced by the PassivHaus concept. “It’s made entirely of timber and it was put together in a factory. Each part was brought to the site already intact, making it extremely airtight,” explains Sainsbury’s David Sheehan. Scientists have even helped the retailer develop a lobby that blows out any air that has been let into the building back through the lobby. 

Tesco (Bourne, Lincolnshire)

Skylights and sun pipes help to radically reduce lighting costs and a rainwater harvesting system flushes the toilets and feeds the on-site car wash. Tesco’s flagship eco-store features refrigerator doors and also boasts a combined heat and power plant powered by renewable biofuels, which the retailer claims puts as much energy back into the National Grid as it consumes. 

Waitrose (Westfield Sstratford, London)

Like M&S, the retailer’s 20,968 sq ft Westfield unit takes its heating and cooling requirements from the mall’s own energy centre. Waitrose’s new flagship is also fitted with water-cooled, propane-based fridges and will send unusable waste food to an anaerobic digestion plant, where it will be converted into renewable energy that will be fed back into the national grid.

Asda (Bootle, Merseyside)

Opened in 2008, this £26m unit, which was built on a derelict brownfield site, features several energy saving and energy generating innovations that makes this store more than 40% more efficient and 50% less carbon intensive than a typical Asda store built three years earlier. The Bootle store has been awarded ‘excellent’ on the BREEAM rating and ‘Exemplar’ by the Carbon Trust. 

Morrisons (Peterborough, Cambridgeshire)

Billed as the next generation of low-carbon buildings, Morrisons’ new eco-store is opening to the public this month. Lit entirely by low-energy LED lighting and roof windows, the Peterborough store also features hydrocarbon refrigerants throughout, electric car charging points and a solar wall that will be used to heat up air in the voids within the cladding.