You could cut 80-cow dairy herd electricity cost by €2,000
Figures presented at Teagasc’s National Dairy Conference in 2010 showed that over 30% of dairy farmers’ electricity usage is spend on heating.
This electricity cost is second only to the spend on milk cooling.
Hot water has relatively limited purposes on farms, usually for cleaning of milking plants, cleaning of milk tanks, and heating of milk replacer for calf feeding (on both dairy and beef farms).
As part of the Teagasc study into electricity usage, a 45% greater electricity usage was discovered on the least efficient farms, compared to the most efficient.
Electricity savings for an average dairy herd of 80 cows could amount to more than €2,000 per annum.
Suggested opportunities to cut electricity usage for heating are as follows.
Reduce your usage
Undoubtedly the simplest and most cost-effective method of saving on electricity costs for heating hot water is to use less of it.
At a basic level, consider stretching the time period between hot washes. Where you currently use a hot wash every milking, is it feasible to move to a hot wash once per day? Of if you currently hot wash once per week, is it possible to move this out to once per fortnight?
Special attention should be paid to TBC counts, and changing cleaning routines should only be undertaken where milk quality is not compromised.
Consider varying your cycles with the seasons. Now that cows are out full time, the exposure to bacteria within the milk plant should be reduced, meaning the time periods between hot washes can be stretched.
Rather than reduce the quantity of hot washes, it is also possible to reduce the volume of hot water used in each wash cycle.
Reduce water temperature
How hot is your hot water or, perhaps more relevant, how hot does your hot water actually need to be?
For routine cleaning, temperatures of around 55 degrees are adequate, with water of this temperature able to dissolve and dislodge fatty residues.
In fact, the majority of dishwashers run at about 55 degrees. Clearly, where a deeper clean is required, thermostats can be turned up to the desired scald.
Where your heater doesn’t have a thermostat, the options are manually turning on and off the heater for a desired amount of heating time, or perhaps the more efficient option of installing a timer.
Consider solar panels
Hard as it may be to believe, this country is actually relatively efficient when it comes to solar energy.
Ireland shares similar irradiation levels to the UK, Belgium, Holland and Germany. If solar works there, then it clearly it works here.
One of the simplest piece of kits I have seen installed on dairy farms involves a hot water storage tank directly connected to evacuated solar tubes. Such a system can easily be rigged up to act as a feeder for an existing immersion. In the event that water from the solar panels is below the desired usage temperature, the immersion will top up the water temperature to the desired setting. Where water from the solar panels is at or above the desired temperature the immersion has no work to do. Temperatures in excess of 85C are achievable in the summer months with this system
Heat recovery systems
One of the most basic heat recovery systems already on farms is the plate cooler.
However, in most instances, the partially heated water from plate coolers is seen as a by-product with little value, rather than a resource.
With proper storage facilities, this pre-heated clean water can be recycled back into the farm’s immersion heater, where a pump is added to generate a pressurised system.
At a more advanced level, a heat recovery system can be installed as an add-on to milk cooling equipment.
As part of the cooling process, refrigerant gases are heated up through compression before passing through a radiator. A heat recover systems intercepts this process to draw heat into an immersion tank rather than letting the supercharged refrigerants blow all their heat out through the radiator. Where milk volumes are low, the consequential energy that can be extracted is also low.
As with cooling equipment, certain equipment meeting the required standards set out by the SEAI can qualify for 100% write-off in one year under the accelerated wear and tear allowance regime for energy efficient equipment.
With heating and cooling, simple measures can often deliver fairly significant savings. Take the time to recalibrate your own system, you might be surprised by what you can save.
