Reducing energy cost and improving energy efficiency
The first step any farmer can take to reduce energy cost is ensure that the farm is on the best tariff and maximise the use of off-peak electricity.
Use night rate electricity for water heating and the morning milking. Night rate hours are from 11 pm to 8 am during winter time and 12 midnight to 9 am for summer time.
Note: There is no charge from ESB networks to install a night rate meter.
Energy saving actions and payback strategy
| Action | cost of action | Annual saving | simple payback |
|---|---|---|---|
| Move to cheapest supplier | none | From €500 up to €5,000 | immediate |
| Milk pre-cooling (installing a plate cooler) | €3,200 | €1,000 | 3 years |
| Install night rate electricity | none | €1,000 | immediate |
| Synchronise water heater with night rate | €50 | €170 | <1 year |
| Variable Speed Drive (VSD) on the vacuum pumps | €460 | €3,300 | 7 years |
| Solar thermal heating | €4,000 | €350 | >10 years |
| Heat recovery system (in addition to pre-cooling) | €3,500 | €350 | 10 Years |
| Photovoltaic system | €6,000 | €700 | 8.5 years |
| Wind turbine | €25,000 | €800 | >30years |
Methods of maximising energy efficiency on your farm
Milk Cooling
Correctly sized Plate Heat Exchangers can reduce the energy costs for cooling milk by up to 50%, which can give a saving of €9 / cow /year.
Use of water to pre-cool the milk before it enters the tank will save about 30% of milk cooling costs - an energy saving of €5 / cow / year.
Vacuum Pumps
Install a variable speed drive to the vacuum pump in the milking parlour. It can give you a 60% reduction in pump running costs, equivalent to €4 / cow / year.
Correct Lighting
Light efficiency is measured in lumens per watt. The higher the lumens per watt the greater the lighting efficiency. Correct lighting can reduce your costs by 50%.
Tip - Replace the 500 watt halogen flood light with an equivalent light output 150 watt High Pressure Sodium lamp. It will save €128 / year and it lasts 10 times longer.