case study tesco Green grocer
Over recent years, Tesco has continuously invested in building energy efficient stores. Chris Phillips explains how service providers have contributed to that process by delivering building services specifically designed to meet Tesco’s objectives at the retail giant’s Ramsey superstore.
generated on-site from renewable fuel, and any excess energy is exported to the National Grid. The store uses a mix of
T
environmentally friendly design, materials and technologies, including: • Sustainably-sourced timber frame; • Roof lights and sun pipes that allow natural daylight into the sales floor and staff areas; • Energy efficient HVAC systems; • Rainwater collection to flush the toilets; • Combined Heat and Power (CHP) plant to generate electricity using renewable fuel; • Refrigerant gases that have virtually no environmental impact; • LED-lit car park, believed to be the first in the UK; • Solar-powered street lights and crossing beacons; • Energy-efficient equipment such as low-energy bakery ovens; • Flooring tiles made from local materials. In 2007, Tesco set itself stretching,
long-term targets to reduce its carbon footprint. One of the targets was to ensure that all new stores, on average,
esco at Ramsey represents a milestone. The store, in a town between Cambridge and Peterborough, is designed to use as little energy as possible. Any energy that Tesco needs is
In 2007, Tesco set itself stretching, long-term targets to reduce its carbon footprint. One of the targets was to ensure that all new stores, on average, emit 50% less carbon by 2020 compared to an equivalent store built in 2006.
emit 50% less carbon by 2020 compared to an equivalent store built in 2006. This is just one part of the plan to become a zero-carbon business by 2050. As part of the pre-start works, HS
Environmental provided a full 3D model of the whole store. The main purpose was to address any co-ordination issues and to help the project team visualise the end product.
The mechanical, electrical,
refrigeration, air tube, sprinklers and roof lights were added to the model to co- ordinate the services with the structure and each other. The model proved extremely beneficial and reduced the amount of site meetings and installation variations. This also reduced the amount of site visits by senior contract managers, which assisted in the carbon payback calculations. A full psychrometric analysis was carried out to assess the benefits of additional dehumidification, the effect of installing refrigeration doors and the effect of replacing the usual door curtains with a specially designed wind sock that is fed from the main sales floor air handling unit (AHU). To achieve the zero carbon store solution, a (CHP) unit was installed that is driven using B100 biofuel. In the event that electricity is over generated the electricity is fed back into the grid. During
44 l Property Management Select l july/august 2010 l
www.pm-select.co.uk
operation, the CHP unit generates large amounts of heat that’s used when required. Excess heat from the CHP is fed to a dry air cooler or a plate heat exchanger located in the energy centre plant room. This heat is then distributed around the store by a low temperature hot water (LTHW) system to the air handling units (AHUs), fan coil units, domestic hot water heater and bulk store heaters. In the event of a CHP failure, there are two gas-fired boilers installed within the plantroom as a back-up. In the summer there is a need for
space cooling. A certain amount of this air is obtained by the cold air spillage from the refrigerated display cases. A dedicated AHU returns and distributes this cold air retrieval back to the main sales floor. In the event of a cooling shortfall, the additional cooling requirement is provided by a chilled water system served from a hydrocarbon chiller.
The hydrocarbon used is propane, the
key selection criteria being reduced operating costs. The global warming potential of the refrigerant is 75 times less than the standard HFC. The sales floor has natural ventilation ‘wind catchers’ that open and close depending on the internal and external conditions. At certain times, mechanically supplied air to the sales floor can then be reduced by 50%.
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 |
Page 61 |
Page 62 |
Page 63 |
Page 64 |
Page 65 |
Page 66 |
Page 67 |
Page 68 |
Page 69 |
Page 70 |
Page 71 |
Page 72 |
Page 73 |
Page 74