Energy efficiency measures: best practices
Stakeholders of the cold chain are currently implementing actions to fight global warming focusing on two main objectives: (i) the reduction of direct releases of fluorocarbons in the atmosphere mainly due to leakages, and (ii) the improvement of energy efficiency to reduce the primary energy use.
Improvements can range from the investment in new and more performant technologies, which have the potential to reduce energy consumption by 15% – 40%, to the implementation of more straightforward and less expensive maintenance and operational practices for the refrigeration system and the overall production process which can frequently reduce energy costs by 15% or more.
Energy efficiency measures (EEMs) have a great potential for introducing noteworthy economic, environmental and social benefits, energy savings as well as a wide range of non-energy benefits, including:
- Increased profitability mainly due to reduced operating costs (e.g., energy and maintenance costs) and increased productivity. Some measures can also provide improved system reliability and a better match between the refrigeration load and the equipment capacity leading to a more efficient system.
- The improved working environment in terms of ergonomics and safety, and reduced impact on the external environment thanks to the lower resources’ consumption and greenhouse gas emissions.
- Reduced vulnerability to fluctuations of the energy prices, which may be sensitive to numerous external factors, such as significant weather events and changes in national and local regulations.
- Enhanced public image. Due to the growing concerns of the community over global warming and other environmental issues, players in the cold chain want to demonstrate to customers that they operate in a responsible way aiming at protecting the natural environment through conservation and sustainable practices.
- Increased sales. A more pleasing shopping and working environment and a reduction of the environmental impact of the cold chain can attract and retain more customers, which are more and more environmental-friendly, leading to an increase in sales.
- Reduced spoilage. Upgrades in the refrigeration and lighting systems and better monitoring and management of the time-temperature relationship allow reducing the spoilage of perishable goods while also saving on energy bills. Waste of products entails the loss of the energy consumed for processing and storing the goods, the production of GHGs, such as methane, during degradation, and the societal impact of wasting resources
The EEMs relevant for the cold chains have been grouped into 10 categories: auxiliary technologies, buildings, employee, energy generation and recovery, industrial symbiosis, maintenance, management, monitoring and control, refrigeration system, and transport.
Each category has a set of factsheets presenting measures from real cases.
Category Type of energy efficiency measure
Auxiliary Technology:
- More efficient ventilation system for cold warehouses
- More efficient lighting system (e.g. LEDs for cold warehouses)
- Efficient motors/filter/pumps/drive systems/ steam generator with the appropriate sizing
- Efficient inside refrigerant cycle: compressor, heat exchanger: evaporator, condenser, throttle valves
Building:
- Improved insulation (e.g., replacement of old windows, removal of thermal bridges, insulation of walls/ceilings/roofs/pipework, reduction of air infiltration of rooms and/or display area, repairing door deals and curtains, ensuring that door can be closed, air curtains on doors)
- Warehouse with separated compartments, with automated glide racks
Energy generation/Recovery:
- Waste heat recovery (e.g., absorption chiller)
- Renewable energy for electrical and thermal energy (e.g., PV, ST, HP, solar cooling)
- Energy storage system
Employee:
Maintenance:
- Regular cleaning of condensers and evaporator coils
- Minimization of compressed air leakages
- Review/ optimisation of the cooling distribution system
Management:
- EMS, energy audit, exploitation of energy benchmarks
- Set temperature range for cooling to upper limit, adjustment of cooling temperatures
Monitoring and control:
- Visualization of EnPis, real-time monitoring system, automated tracing
- Use of smart heating systems/ automatic/ intelligent control system
Refrigeration System:
- Less oversized cooling systems
- Alternative refrigeration technology, design and refrigerant, retrofitting refrigeration display systems, closed display cabinets
- Refrigerant cycle (e.g., one, two stage, intercooler etc.)
- Design and usage of free cooling
- Alternative refrigeration technologies: e.g., solar cooling systems, thermal chillers, heat pumps
- Retrofit of R22 refrigeration system by centralized ammonia (NH3) system
Transport:
- Improved insulation of trucks (e.g., air curtain)
- Fuel monitoring for drivers and training drivers for fuel consumption reduction
- Optimised travel routes (e.g., reduction of empty return trips), modal shift
- Alternate means of transport (e.g. portable refrigerated units for LTL)
Industrial symbiosis: