Energy usually comprises a small percentage of total operating costs for food and grocery stores, but it’s a significant proportion of the tight profit margins of many retailers.
In food and grocery stores, refrigeration is the largest consumer of energy, operating non-stop and responsible for around half of the store’s total energy consumption. Lighting and general power usage, including hot water, make up around 25% of consumption. HVAC comprises the remainder.
Challenges faced by food and grocery stores include:
- lack of staff time and capacity to manage energy-efficiency improvements
- low margins that make significant investment in energy upgrades challenging
- split incentives between building owners and store managers.
By starting with low-cost approaches to efficiency improvements, significant savings can be achieved quickly and reinvested into more extensive energy-performance upgrades.
There are several ways to reduce energy consumption at low cost. Establishing an effective maintenance program can identify and address equipment issues before they lead to wasted energy.
Reducing over-lighting by de-lamping is often possible without impacting on safe lighting levels. It’s worth installing occupancy sensors to reduce lighting and plug loads in storage rooms, offices and low-traffic areas.
Ensuring the temperature settings of refrigeration units are optimised is another easy win, as is cleaning the cooling coils on all refrigeration units.
Good staff habits can help reduce energy consumption, especially in older stores.
Establish procedures to ensure lights in storerooms and bathrooms are switched off. Turning off appliances, displays and lighting at closing time can deliver useful energy cost savings.
Closing doors to unused areas or to the exterior and using natural ventilation can substantially reduce HVAC costs.
Refrigerated display cabinets
Refrigerated display cabinets (RDCs), refrigerated storage cabinets (RSCs), ice cream freezer cabinets and scooping cabinets are used in a variety of locations including petrol stations, convenience stores and delicatessens.
Installing aerofoils along display shelves can be a cost-effective way to reduce cold air losses from existing open cabinets. In some cases, installing transparent doors to open cabinets, or upgrading to double glazed doors, can prove to be cost-effective. Ultimately, investing in a new system will deliver the biggest benefits.
In 2019, a new efficiency standard for RDCs was implemented by the Australian Government, improving the average energy efficiency of new refrigerated cabinets and extending the range of cabinets covered under the previous standard. For more information. see the Energy Rating website.
Improving the efficiency and reducing the load on refrigerated storage facilities can save substantial energy and increase reliability. As many refrigeration storage systems are ageing and inefficient, there is potential to reduce energy consumption by as much as 40%.
Limiting infiltration with good sealing and keeping the door closed as often as possible can reduce the load on the cold store. Other opportunities for savings can be found in better insulation, equipment selection and setup.
To read more, see the Refrigeration guide.
Lighting is a good place to start when looking to reduce energy costs. Upgrading to LED reduces energy consumption and lowers replacement and maintenance costs given their longer life.
If well selected for the application, LED bulbs can show truer, brighter colours, helping to increase sales. In addition, LED lighting doesn’t emit UV light so fresh produce doesn’t age as quickly.
To read more, see the Lighting guide.
HVAC is vital to provide customers with a comfortable shopping experience and maintain food quality. HVAC needs can be minimised through good building design, for example by controlling heat gain through windows and walls and reducing infiltration.
Changing HVAC filters regularly and ensuring equipment is well maintained and tuned will also help save money. When purchasing HVAC equipment, such as reverse cycle heat pumps, it’s worth investing in the most energy-efficient models. These can save more than 50% in related energy costs compared with minimum-standard models.
To read more, see the HVAC guide.
Cooking appliances can represent a surprisingly high proportion of total energy use in the food retail sector. Choose well insulated models with double or triple glazed windows. The most efficient models can be as much as 40% more efficient than the market average.
Hot water heating typically accounts for a small percentage of energy consumption in food retail, but there remain some easy opportunities to save money. Ensuring pipes and fittings are well insulated can reduce energy losses by as much as 25%.
Reducing the thermostat to the lowest safe, practical temperature is also a good idea. When buying a new hot water system, it’s worth considering heat pump or solar hot water as these technologies can repay the upfront cost within a few years.
Energy audits identify quick-win opportunities as well as informing a longer term strategy. Energy benchmarking can enable ongoing review of energy consumption to ensure that energy performance is always improving.
Sub-metering and energy data monitoring systems can inform more formal energy management systems, and deliver a number of other benefits.
Circular economy and waste management
The concept of the circular economy reimagines waste as a valuable resource, rather than just a problem to be minimised. Companies are recognising the shift in consumer preferences towards environmentally responsible products.
Supermarkets are experiencing an increase in demand for home delivery services. In response, supermarkets are formalising deals with a range of food delivery platforms and on-demand couriers. Woolworths has launched a trial of electric panel vans as part of its online delivery fleet in South Africa.
To read about the Australian Government’s approach to supporting a circular economy see the Global Australia website.
The use of both onsite and offsite solar PV to power stores is increasingly common. Solar PV is well suited to the higher daytime loads that food and grocery stores are subject to.
There are opportunities to take advantage of existing thermal mass and store energy via refrigeration in cold storage. This can be further added to using phase-change materials (PCM) including ice. PCM thermal energy storage together with a refrigeration system can be used to store substantial renewable energy generated by solar PV.
There is also likely to be an increase in the integration of electric batteries into refrigeration systems, as the economics of batteries steadily improves.
To read more on how to generate your own energy, see the Renewables guide.
In chillers, heat from the refrigeration process is expelled via air-cooled condensers or cooling towers. Modern chillers, in particular those using ammonia or CO2 refrigerant offer significant potential to recover wasted heat at useful temperature levels (greater than 50°C). This recovered heat can be used to offset the consumption of other operations, such as heating water.
To read more, see the Waste heat recovery guide.
A regulated gradual phase down - by about 85% by 2036 - of hydrofluorocarbons (HFCs) is underway in Australia and worldwide as these refrigerants have high global warming potential (GWP). New refrigerants with low GWP and high efficiency are expected to become available as the market responds to the new regulations. Many of these are based on ammonia or CO2.
Ask your service provider about the best available products for efficiency and environmental performance.
Internet of Things (IoT) and predictive control
The application of intelligent, cloud connected IT systems to refrigeration systems promises to enable even greater energy costs savings in supermarkets. Strategies can be tailored to operating objectives, including minimising total cost and reducing energy consumption, while ensuring internal temperature conditions are satisfied.
To read more, see the Industry 4.0 guide.
World-first green bond supports Woolworths’ sustainability strategy (CEFC) Australian Government
A study of waste in the cold food chain and opportunities for improvement (PDF 1.17 MB) Australian Government
Refrigerated cabinets Energy Rating
Reduce refrigeration costs in your business Victorian Government
Energy Savings Tips for Small Businesses: Grocery and Convenience Stores US Department of Energy