Engineering manager Simon Waldron took the stage at the LuxLive EcoLight Arena and detailed two SSL retrofit projects at UK Sainsbury's supermarkets that delivered energy savings and better lighting.
We've previously reported on a number of Sainsbury's LED lighting retrofit projects. For example, the company worked with GE Lighting on a solid-state lighting (SSL) retrofit at one store that used GE's Intrinsx-based Lumination-eries products with the planar lighting surface oriented vertically to deliver better lighting on shelves. Earlier the company had moved to LEDs to light refrigerated cases working with Nualight.
The retail chain, however, has around 600 supermarkets and 650 convenience stores in the UK, and a broader move to LED-based lighting is a key cog in its environmental program called "Respect for the environment." Moreover, the company is committed to energy reductions of 65% relative to the operational energy it used in 2005, for a 30% overall savings.
Waldron, engineering manager at Sainsbury's, said, "In order to reduce the running energy cost of lighting, the move to LED was clear." But he added that the transition is a significant challenge. He said that you can't just peruse the catalog of a lighting company and that you must understand performance of luminaires and the stated values of potential suppliers.
The company established a guideline requiring payback in five years or less for LED lighting retrofit projects. Most are delivering quicker return on investment (ROI). Still, Waldron said companies should consider total cost of ownership (TCO) when planning a project. He showed a sample comparison of SSL with high-output T5 fluorescent lighting. The T5 option was cheaper at the five-year mark but over 20 years LEDs provide a significant advantage.
Wolverhampton supermarket
Waldron provided details on a couple of notable projects, including the supermarket in Wolverhampton that was the first 100% LED-lit store. The SSL retrofit includes the sales floor, back-of-house operational areas, the adjacent petrol station, the parking area under the store, and more.
The company is both carefully choosing fixtures from many sources and how those products are being deployed and controlled. On the Wolverhampton sales floor, Waldron said 2.1 km of Zumtobel Tecton linear LED fixtures were installed. Prior to 2012, the company lit the sales floor to 1000 lx. Now the standard is 800 lx and 650 lx where skylights are installed. Moreover, all of the sales floor fixtures include controls and dimming support.
In the undercroft parking area, Waldron said that the LED lighting retrofit resulted in 103 fewer luminaires being installed. In part the reduction was due to placing light where it is needed. He said the company is no longer lighting the tops of cars.
Overall, the Wolverhampton store now uses 56% less energy than before. Expected payback is 3.2 years. The project utilized 27 different SSL luminaires in total that integrated a total of 214,000 packaged LEDs,.
In-aisle lighting
The presentation also included details on a supermarket project in Debben in which Sainsbury's has experimented with a new approach to lighting shopping aisles. The store underwent a major renovation including an expansion from 6000 ft2 to 11,000 ft2. Still, the company reduced the luminaire count on the sales floor from 253 to 207.
The established methodology for sales-floor lighting uses a cross-aisle approach in which the LED luminaires run perpendicular to the shelves. That approach delivers a lot of light on the aisle floors but less than ideal vertical illumination on the shelves and merchandise.
In the food shopping area, Sainsbury's installed lighting is positioned in the middle of aisles and the linear fixtures run parallel with the shelves. Waldron said the approach is delivering more lux on shelves and more uniform lighting on the merchandise. He quipped, "We don’t sell [floor] tiles," essentially pointing out the performance of the prior cross-aisle lighting.
Waldron said the project at the Debben store will achieve payback inside of two years. Moreover, the LED lighting retrofit is delivering 117 kWh in annual energy savings.
