A carrot processing plant approached us for an assessment under the Energy Savings Opportunity Scheme (ESOS). The survey included a detailed site inspection, a thorough analysis of previous 18 months of energy bills for the site and a survey of the transport fleet.
The company had already invested in major upgrades to the site, including fitting an anaerobic digester and associated combined heat and power plant generating their own electricity, a 50kW photovoltaic system and new offices, lorries and processing equipment. They still however buy in over 6,400MWh of energy per year.
We produced a series of recommendations that could be easily implemented, with paybacks for the package of 3 years or less.
|Current Energy use p.a.||Estimated annual savings|
|Energy bill||£500,000||£50,000 p.a.|
|Energy consumption||6,400 MWh||700 MWh p.a.|
Our main recommendations were:
With such a high electrical consumption, this is a very worthwhile improvement, which reduces the excess power being delivered from the Grid.
A quote had been obtained previously for LED lighting but there was an issue of trust with the supplier. We investigated the quote thoroughly and recommended that 84% of the fittings should be replaced which would give over 90% of the savings of carrying out a complete change. We recommended a strategy for low illumination at night to satisfy safety and maintenance concerns. We also recommended daylight and movement sensors.
Combined Heat and Power Unit
We recommended that more use be made of the waste heat from the CHP plant. At present this is only used for the relatively small office building and the vast majority of the heat is thrown away. As the site has a major cooling load and some relatively old chillers it was recommended that the oldest chillers are replaced with absorption chillers. Replacing these chillers would also reduce the risks from refrigerant leakage as they run on R404A refrigerant. Alternatively ancillary businesses could be considered to use the waste heat, eg the wood dryer or greenhouses.
Our analysis of the transport fleet allowed us to recommend improvements in efficiency.
“We were really impressed with the team that carried out the ESOS audit and thought that many of the suggestions they came up with are worth looking into – so thank you for doing a great job!”