Practical Guide: Introduction to Energy Auditing
Each litre of diesel consumed releases around 2.675 kg of CO2 into the atmosphere. Similarly, each kWh of electricity recorded on the farm meter results in 0.117 kg of CO2.
Savings of 10% - 20% can often be achieved through simple actions. By following a step by step approach, an energy audit can help to identify a range of CO2 savings and reduce energy and fuel bills.
Quantify existing energy usage:
In order to target savings you need to know where energy is being used:
- Keep records of fuel and electricity usage
- Install additional meters to provide usage data for individual buildings or pieces of equipment
- Match fuel use to equipment and task
- Calculate usage per livestock unit or per tonne of grain or ha of land or litre of milk and compare with industry standard figures
Identify savings and actions:
- Involve staff - identify ‘Energy Champions’
- Consider working practices as well as equipment efficiency
- Prioritise energy saving options.
- Zero and low cost options can be implemented immediately
- Plan forward where investment in capital or time is required
- Continue to monitor and review progress regularly
Where to look for savings
- Where buildings are heated or cooled it is important to ensure that air leakage is kept to a minimum. Drafts should be eliminated by sealing up gaps. Automatic door closers or strip curtains should be considered for frequently used openings.
- Heating and refrigeration systems should be regularly serviced to maintain efficiency. Setting and function of controllers should be regularly checked to prevent over heating or cooling.
- Recirculation of air within a building should be considered to redistribute heat to where it is needed.
- Compact fluorescent bulbs will use 80% less energy than conventional bulbs and should be used where lights are regularly switched on for more than a few minutes.
High intensity discharge lamps will use much less energy than incandescent lamps for lighting large areas.
Motors, fans and pumps
- Motors, especially those driving fans and pumps, often don’t need to run at full speed all of the time. Fitting variable speed drives can result in substantial savings for motors that run for long hours.
Fuel performance of vehicles will be influenced by the following factors:
- tyre pressures, lubricant levels
- regular maintenance
- correct matching of tractors and equipment
- equipment set-up
- driver training
Energy waste ‘hot-spots’
- Poorly matched tractors and implements.
- Heating or cooling of poorly insulated buildings.
- Badly maintained vehicles and equipment.
- Incorrectly set controls for heaters and refrigeration plant.
- Failure to turn off lighting, heaters, fans etc due to careless working practices.
- Inefficient, outdated lighting.
- Poorly insulated hot water tanks and service pipes.
- Double handling of produce.
- Over-drying of grain.
- Leakage in compressed air or vacuum systems.
- Dirty grilles, ducts and fans in ventilation systems causing unnecessary back pressure.
Our Practical Guides cover five useful topics:
- Use energy and fuels efficiently
- Renewable energy
- Lock carbon into soils and vegetation
- Making the best use of nutrients
- Optimise livestock management
Top Tips for EVERY farm
A good starting point is to carry out an energy walk round:
- Ask staff to help to identify where energy is being wasted
- Increase awareness of energy issues
- Identify your most likely areas for savings - see the list of typical wastage situations overleaf
- Identify repair or maintenance work that will reduce energy costs
- Identify where there is a need for capital investment to reduce energy costs - “spend to save”
Repeat “walk round” at different times of day and times of year.
Typical Energy Figures
- On average, an arable unit of 150 ha will use 10,500 kWh of electricity and 8500 litres of diesel purely to dry grain even in a relatively dry year. This equates to around 24 tonnes of CO2.
- On average, a 100 cow dairy will use 30,000 kWh of electricity annually, resulting in the release of 3.5 tonnes of CO2.
- On average, a pig unit will use 36 kWh of electricity per pig (from farrowing through to finishing) – 4.212 kg of CO2.
A 10% reduction in the consumption of fuel & electricity on Scotland’s farms would result in 48,000 tonnes less CO2 being released as well as reducing fuel and energy bills by 10%.
Related Practical Guides
- Electricity use in the dairy (507.5 KB, PDF)
- Optimising tractor fuel use
- Monitoring Energy Use
- Spreadsheet - Vehicle Fuel Record (105.2 KB, XLSX)
- Spreadsheet - Grain Drier Fuel Record (105.92 KB, XLSX)
- Spreadsheet - Electricity Meter Record (106.16 KB, XLSX)
- Tyre selection and management
- Making the most of on-site energy generation (640.79 KB, PDF)
- Case Study: Improving Fuel Use; hydrogen technology (1 MB, PDF)