ENERGY REDUCTION SAINSBURY’S
Sainsbury’s new store in Leek is its fi rst to be lit solely by LEDs
The cold front In a similar way to the advances in LEDs, the use of carbon dioxide (CO2
)
as a refrigerant is another carbon-saving technology that required time and effort to bring to a point where Sainsbury’s was comfortable to use it in its new stores. Refrigeration is a vital issue for Sainsbury’s as it makes up 40% of its total energy use. On its larger stores, Sainsbury’s uses
a refrigerant circuit to remove heat from the rows of chilled cabinets and freezers, via individual heat exchangers. The circuit transfers the heat to a large refrigeration plant, usually tucked out of sight on the store’s roof, where the heat is removed and, in most cases, used to provide space heating. On top of the carbon associated with the energy consumed by a store, there is always the risk of F-gas leakage from these large refrigeration systems. To tackle the problem, Sainsbury’s set
out to replace conventional refrigerant plant with non-ozone depleting CO2
-
based plant. Initially, Hawker says the technology was up to 40% more expensive than the conventional system. As a result, Sainsbury’s worked with three suppliers, who had aligned themselves with European manufacturers producing CO2
-based plant.
a product, it will investigate the robustness of its supply chain and quality-control systems to ensure they meet its exacting requirements. Only when a product has met the retailer’s technical, commercial and quality demands will the team consider trialling it – and even then only in a non- trading environment. Most products for use in stores are tested
initially in what Hawker calls ‘mock-shops’. Sainsbury’s has two of these facilities – one in Coventry and one in north London – where products are put through their paces in a simulated supermarket interior. ‘For lighting, we’ll use these facilities to assess power consumption, light output, cost to install and cost to operate,’ explains Hawker. Only about 10% of the products tested
make it successfully through the mock- shop. Those that do ‘might’ be trialled in an actual store. If that is successful, the product will be incorporated into the retailer’s standard specifi cation for roll-out across future stores.
www.cibsejournal.com
Each supplier’s refrigeration equipment was trialled in two stores. ‘These six stores enabled us to learn about the good and bad of each system to come up with a Sainsbury’s standard.’ CO2
refrigeration technology has now
evolved to a point where capital cost and effi ciency are the same as those of conventional refrigeration plant. To date, CO2
THE WASTE CIRCLE
None of Sainsbury’s waste goes to landfi ll. Comprising a mixture of cardboard, plastic, food, oil and paper, it is all put to positive use. Food fi t for human consumption is donated to charities to help tackle food poverty in the UK. Bread waste goes to animal feed with the remaining food waste going to anaerobic digestion to produce gas that is burnt to generate electricity and fertiliser; cardboard is baled and recycled, as is plastic; wood waste is recycled, as is paper. ‘You do not throw stuff away, instead you re- use it in a circular economy,’ says Hawker.
refrigeration has been installed in 160
larger stores. ‘It has made a big dent in our carbon footprint,’ says Hawker. Heating is another area where the engineering team is starting to make signifi cant carbon savings. Biomass is now the default heating system for shops up to 5,570m2
and Sainsbury’s has
78 local stores that run on it. The fuel comes from a Scottish fi rm that makes timber construction products. It uses timber thinnings to power a CHP plant, energy from which is used to process the remainder of the thinnings into pellets. Delivery to stores in the north of the UK is by road; for the south, the pellets are sent by boat to Purfl eet in the Thames Estuary, before distribution by road to stores. Where it is cost-effective, some of the retailer’s larger stores use a closed-loop ground-source heat pump to provide
The retailer is the ‘biggest’ user of photovoltaic arrays in Europe, with 750,000 individual panels installed on the roofs of supermarkets and distribution centres
August 2013 CIBSE Journal 29
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49 |
Page 50 |
Page 51 |
Page 52 |
Page 53 |
Page 54 |
Page 55 |
Page 56 |
Page 57 |
Page 58 |
Page 59 |
Page 60