Energy & Water in the dairy
Different sources of energy are available to produce electricity for use in the dairy. Some sources are renewable (e.g. solar, wind, hydro) while others finite (e.g. coal, gas, oil). Energy can be used to produce heat (e.g. solar hot water).
In Australian dairies, electricity is the dominant form of energy. About 40% of a farm’s electricity is used to heat water. The remainder is split between cooling milk (~30%), dairy pumps and motors (~20%) and lighting (~10%).
Using energy efficiently will benefit farm operating costs. Obtaining electricity using renewable energy sources such as solar and wind technologies will reduce the farm’s contribution to climate change through lower greenhouse gas emissions.
There are many practical and often simple ways to use energy more efficiently.
Energy is also consumed in buildings and products. Selecting products and construction materials that are durable, efficiently made and generate lower operating costs are positive ways of reducing the dairy farm’s carbon footprint.
Water is a precious resource that requires careful management - in the future we will have to be more accountable for how we use it. Different applications demand water of specific quality. Save the best available quality for the most demanding applications, such as milking machine and vat cleaning, as well as staff hand washing / shower facilities. Yard washing is an ideal application for recycled water.
Energy at work on the farm
‘Ken’ is looking to milk around 1,100 cows on a new farm north of Mt Gambier. The new 60-unit rotary dairy will be built on a greenfield site. He is keen to incorporate energy efficiency in as much of the new dairy as possible. Efficient use of water is
Ken has identified three areas where he thinks efficiency improvements will have the greatest impact. The first is in the way water is heated; the second is how his milk pre-cooling could be improved (refer to InfoSheet B4: Cooling Milk for details see details in Additional Information on page 56); and the third area is how water is used at the dairy and where savings could be made. Energy-efficient lighting and other power saving devices will be incorporated into the shed design.
Improving water heating
As there will be different staff working at the new dairy, Ken says simplicity is very important. A solar hot water system with evacuated tube collectors will be used to pre-heat the water. The pre-heated water will be stored in three highly insulated tanks from where it will be fed into the electric hot water services. The 40,000-litre vat will have a heat recovery system included. The calculated amount of hot water required each day at the new dairy will be as shown in the table.
Water at work on the farm
‘Frank’ from Victoria milks 380 cows in a 30-unit dairy. The milking equipment and the milk vat each have an automatic cleaning system. Milking takes around 2¼ hours in the morning (cups on to cups off) and about two hours in the afternoon. The current water use for each part of his system is estimated below.
Knowing his current daily water use helps Frank evaluate options. Compare the ‘total water use per day’, the ‘% new water added each day’ and the ‘% re-used and/or recycled’ - they highlight the differences.
What you need to know (Victoria only)
Disclaimer: The following is only a guide to the law affecting farmers in the environmental field. The general area is quite complex and affected by numerous Acts and Regulations, some of which are very detailed. In addition, changes are made on a regular basis to the legislation. The precise effect in a given situation will require expert advice and this should be sought from an appropriate professional or the relevant government agency.
These resources can help you develop your Action Plan (Organisations, their contact details and website information were correct at time of publication. This information may change without notice).