UPDATED: The Southern Co-operative to install its first CO2 system

The Southern Co-operative, which has 120 shops in the South East of England, will install its first chiller cabinets using CO₂ as a coolant, in a landmark store planned for Bagshot Road, in Chobham Surrey, UK. The UK has seen significant investment in CO₂ with over 260 CO₂ transcritical refrigeration installations across the country. UPDATE: The CO₂-based installation saves Southern Co-operative over 69 tonnes

Since the first CO₂ installation in Swansea in 2006, the numbers of CO₂ systems in UK supermarkets has grown rapidly. Retailers have largely led investment in CO₂ technology, and the list of companies having chosen the natural refrigerant now includes Asda, the Co-operative, Harrod’s, M&S, Sainsbury’s, and Tesco. The Southern Co-operative is the latest supermarket chain to select CO₂.

Supermarket chain’s most efficient and climate friendly store

Steve Tremlett, Head of Business Development for Southern Co-operative, confirmed that the new store in Chobham would be their most efficient in the UK.

“All of the lighting will be LED, the refrigeration systems will actually use CO₂ as a climate friendly coolant and the fridges themselves will have doors to help minimise power consumption. Power will also be saved through hi-spec insulation; and electricity is monitored using sophisticated smart meters to ensure that store equipment is running efficiently,” said Mr Tremlett.

Several Southern Co-operative stores have already installed LED lighting and electronic smart meters, achieving an overall reduction in energy use of 2.6%. However the Chobham store will be the first to use CO₂.

CO₂ installation by DCI Refrigeration

The Southern Cooperative will work with refrigeration and air conditioning contractor DCI for the CO₂ refrigeration installation. In 2011, Phil Ponsonby, Chief Operating Officer for the Southern Co-operative, opened the new DCI CO₂ test and training facility.

At the opening Mr Ponsonby said, “With increasing demand for efficient and environmentally friendly refrigerants, DCI has demonstrated CO₂ offers perhaps the most viable solution, particularly in the food chain where demand for chilled and frozen food continues to grow”.

Use of CO₂ as the prime refrigerant in the 52kW glycol chiller, designed and manufactured at DCI premises in Portsmouth, provides the established GWP benefits of using natural refrigerants to reduce direct emissions. The system thus contributes to the overall carbon savings, together with the use of renewable energy sources - both on site and via incoming electricity supply from hydro-electric and wind power providers.

Significant carbon and power savings

Contributing to significant emissions savings amounting to 69 tonnes CO₂ equivalent are the: tailored design, innovative refrigeration technology, climate control and energy management system, sustainable timber-framed construction, insulation exceeding Building Regulations and renewable energy sources.

Special carbon and energy saving features include:

Glass doors on chiller cabinets provide energy savings of over 30%, emission reduction of 10.5 tonnes CO₂ equivalent and eliminate the need to heat the cold aisle thereby saving additional 8.9 tonnes;
Heat recovery system designed by DCI that uses heat generated by the refrigeration plant to provide hot water for radiators and sink usage and this is backed up by an energy efficient air to water heat pump;
Ventilation via heat exchange either pre-heats or cools fresh air with extracted air to save further energy;
LED lightning which uses 75% less electricity than conventional fluorescents;
Energy Management Panel controls operational periods for store lighting, signage, bakery ovens, heating, ventilation and non perishable refrigerated display cabinets ensuring these systems use energy only when needed and saving 20 tonnes of CO₂. Overall, the Energy Management Panel saves around 24 tonnes of CO₂ equivalent;
Timber construction refrigeration plant room, 100% recycled and sustainably sourced, the first of its kind for any retailer.

CO₂ training facilities in the UK

The increased investment in CO₂ has been accompanied by a growing number of CO₂ training courses. Based in Portsmouth, in the south of England, the DCI CO2 facility is the second of its kind in the UK, equipped with Bitzer semi-hermetic CO2 compressors in subcritical and transcritical operation. The first CO₂ training centre was opened in 2010 by WR Refrigeration, and is called the “European Academy for Carbon Dioxide”. The WR Academy comprises three systems in a cascade arrangement: a sub-critical LT system, a pumped circulation CO₂ secondary system, operating at chilled food conditions, and a cascade CO₂ transcritical multi-compressor pack system.