Over the next five years the cost of heating, cooling and lighting your store is going to go through the roof an appropriate metaphor, perhaps, because through the roof, the doors and the windows is where most of your money is going now.

With global demand soaring and natural materials dwindling, power-hungry convenience stores as we know them are in for an electric shock if the estimated 40% rise in energy prices by 2015 comes about as predicted. Managing consumption will be a number one priority, and achieving that will require long-term planning and that is going to involve investment in new technologies.

On top of that, legislation to protect our battered environment and limited resources will force retailers to make significant and costly changes to their capital equipment. Many of the refrigerants currently in use in your chillers, for example, are to be phased out from 2012 because they contribute to global warming.

And if that's not enough, the energy efficiency of your premises is expected to be included in the assessment of your business rates, too, as energy inspections and certificates become mandatory.

There's yet another factor. "Convenience stores in 2015 are likely to have an even greater emphasis on food to go than they do now, and despite environmental concerns I expect that a much larger proportion of shop floor space will be given over to refrigeration," says Dominic Perks, managing director of shopfitter Uno Retail Solutions.

"There will be a requirement for the refrigeration industry to become more environmentally friendly, but it won't come cheap. Developments of this nature are costly, and retailers will have to pay more for them," he adds.

On the plus side, the technologies currently being touted as energy and environment savers are starting to deliver on the reductions they promise, and the cost of implementing in stores them will come down as they become more mainstream.

One example already earning its keep at David Knight's Budgens store in Hassocks, West Sussex, is a refrigeration system which uses cold air from outside to reduce the cost of chilling stock. There's no water or refrigerant inside the store, and on colder days the system provides cooling for next to nothing. David obtained an £85,000 Carbon Trust loan to fund the installation, and with an estimated 50% cut in energy use, he's looking at a swift payback.

Dave Melhuish, development and facilities manager at Midland Co-operative, points out that refrigeration represents the largest single use of energy in a store, and as is often the case the Co-op is a few years ahead of the pack in exploring more efficient technologies. "We are planning a rollout of energy efficiency upgrade measures to refrigeration equipment next year, along with a replacement programme for inefficient freezers," he says. "We aim to only purchase integral refrigeration that uses hydrocarbon refrigerants from 2010, and will continue to develop the use of CO2 as a refrigerant."

Midland's new store in Oakham, Leicestershire, although supermarket-sized, is a test-bed for several technological leaps which will be equally applicable to c-stores by 2015.

Environmentally friendly refrigerants carbon dioxide and propane are used throughout the refrigeration system technologies which as yet are rare in c-stores, but are expected to proliferate and become far more efficient, and affordable, in the next few years. These systems are monitored by electronic controls which ensure the chillers and freezers run at optimum efficiency.

Cleverly, the cold water used in refrigeration on the shop floor also provides localised cooling for the staff areas when necessary. Similarly, the heat removed from the chillers usually rejected outside the building is reclaimed for re-use in heating.

Coldrooms and display cases are fitted with LED lighting which uses 60% less energy than conventional lighting LEDs provide light but produce very little heat. All lights are controlled by sensors to ensure they are on only when required.

'Everclear' glazing reduces the direct energy consumption by 50%, and dual air curtains, front thermopane glass risers, and new-design fans all add to the savings.

The store makes the most of freely available resources. Fresh air is distributed throughout the building by ventilation louvres installed in the walls and roof of the building, so the heating and cooling load is kept to a minimum, and with a roof that's 15% window, sunlight reduces the job done by artificial lighting.

Heating debate

Overheating is reduced by a large overhanging canopy to the front of the store and automatic window blinds regulate sunlight.

The store's lighting levels are maintained automatically by light sensors in the roof. When the natural sunlight reduces, the shopfloor lighting gradually increases.

On top of all this sits a 'living roof' of stone and earth planted with mixed sedum. This absorbs the sun's heat during summer periods, which controls the temperature within the store.

On less pleasant days, rainwater is collected and stored in an 22,000ltr underground holding tank, and re-circulated to the building through a series of filters and anti-bacterial ultraviolet lamps for use in non-drinking services, such as the toilets.

So just how quickly can we expect to see these advances become mainstream? Midland's Melhuish says: "Low-energy lighting and heat pump technology have been in use by the Society for some time, but we are already expanding the use of LEDs into many areas, and will look to retrofit such new technologies wherever practicable."