Kettle Produce - eat your greens and go green
Background
Kettle Produce took on a Business Environment Partnership (BEP) funded student, Wayne Stenhouse, to conduct an energy efficiency project. The objective was to conduct a detailed analysis of current energy consumption and identify areas in which energy efficiency could be improved.
Kettle Produce are specialists in growing, processing and marketing a wide range of whole and prepared (freshcut) vegetables to several major supermarkets and food service businesses in the UK. Kettle Produce were established in 1985 and are based near Cupar at Balmalcolm Farm.
Energy usage was identified
Initially Wayne categorized the energy usage into 4 key areas: refrigeration, machinery, lighting and compressed air. By looking in depth into each area a series of recommendations were made in which the energy consumption could be reduced. Recommendations involved either a change in current strategy or the installation of energy saving technology. It was found that the greatest energy saving measures were to be found in the refrigeration and lighting systems.
Refrigeration systems
As Kettle Produce handles fresh vegetable produce, large areas within the plant are refrigerated. This is the most energy demanding task, making up 41% of the total electricity consumption. The company had already investigated the viability of installing electronic expansion valves, therefore consumption had to be reduced by other means. Wayne investigated each area to analyse the current provisions in place and scrutinized means in which to reduce consumption.
It was determined that the refrigeration energy demand could be significantly lowered by reducing cooling during non productive hours. It was noted that the cooling provisions could not be switched off if raw material or product were being stored in the area.
In a packaging area it was possible to switch off the refrigeration provisions for approximately 9 hours per day. In the majority of other areas food produce is present therefore cooling provisions cannot be switched off. However even in areas with food produce the cooling provisions can be reduced during non-operational hours.
This would be achievable by reducing the cooling units in use overnight, or by increasing the temperature set point. Every 1ºC increase in temperature reduced energy consumption by 2%. By implementing these measures throughout the factory, savings of £22,150 per year are possible.
Lighting systems
To analyse the current lighting setup a light intensity recording was taken for each of main areas within the plants and compare with health and safety requirements. It was found that the light intensity was over double the published recommended figures.
Recommendations made were specific to each individual area. Methods for energy reduction included the installation of manual switches, automatic timer switches and occupancy motion sensors. Savings of £9,938 are possible by implementing these changes to the lighting system.
Business and environmental benefits
If all the recommendations were implemented, the energy consumption at Kettle Produce would decrease by 4.3%. This would give a total projected saving of £33,188. As a direct result of reduced energy usage, the company’s CO2 emissions would be reduced by 215 tonnes.