Energy saving on farm
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4 min read
Improving energy efficiency on your dairy farm can lower costs, extend equipment life, and reduce emissions. You can build a more sustainable and cost-effective operation by understanding where energy is used and making smart changes, like using solar power, optimising milk cooling, and upgrading equipment. Explore practical ways to save energy and boost efficiency on your farm.
Why being energy efficient is important
Energy plays an important role in agriculture, with electricity and diesel being the primary energy sources used on New Zealand dairy farms.
Energy-efficient farms can use up to five times less energy per milk solid produced. Improving your energy efficiency can also help prolong the lifespan of your equipment. Additionally, finding energy efficiencies can create opportunities to enhance resilience by integrating renewable energy sources and electric power investments into your operations.
The benefits:
- Reduce operating costs
- Improve returns for investors
- Enhance productivity
- Build a more sustainable business in the long term
- Benefit the environment by reducing greenhouse gas emissions
- Create added value for customers
Where energy is used
To become more energy-efficient, it’s important to understand how you currently use energy, how to measure it, and explore ways to optimise equipment usage to reduce energy consumption.
On a dairy farm, stationary energy use is generally distributed across the following activities:
The graph above shows electricity usage for the dairy farming sector during 2022 (ref: EECA End Use Database)
Ways to save energy or use energy wisely
Solar panels
Installing solar panels can save money, increase resilience, and reduce carbon emissions. Solar systems operate reliably with minimal effort, maintenance, or parts replacement and have an expected lifespan of 25–30 years. Changing when you use power and maximising your use of solar energy can improve your payback.
Milk cooling
Reduce electricity use by insulating the milk vat to minimise heat gain, which reduces the load on the refrigeration system. External factors such as wind, sunlight, high groundwater temperatures, rain, and summer heat can cause the milk vat to gain heat, making the refrigeration system work harder than necessary. Proper insulation helps chill milk faster while using less energy. Insulate both cold and hot water pipes to improve energy efficiency. Check the plate cooler temperature to ensure the milk being picked up is no more than 2°C hotter than the incoming water. Pre-chilling water can help farms take advantage of cheaper power. For advice on the best refrigeration solutions for your dairy farm, consider consulting a refrigeration company.
Hot water
Wrap cylinders and insulate hot water outflow pipes. Check for leaks around pipes, cylinders, and chillers. Install timers on hot water cylinders and consider increasing storage capacity to take advantage of cheaper power rates, or solar energy. Using solar power or night rates can be 20–50% cheaper.
Lighting
Replace all lights with energy-efficient LEDs which are also better to work under and use natural light where possible by installing clear corrugated sheets. Install motion detector lights and automatic timers in passageways. Good lighting can improve cow flow and increase milking efficiency. Combining natural lighting with LEDs can help reduce operating costs and is often the preferred lighting in the shed. Consider using switch timers for lighting and timers on equipment that can operate during off-peak times, such as pre-chillers and pumps. Motion-activated lights can also be beneficial in and around the dairy.
Electricity bills
Heat removed during milk chilling often goes to waste but can be used to preheat water for cleaning, cutting your shed's electricity bill by up to 30%, often paying for itself within two years. Regularly check your electricity bills to find savings and ensure they match your meter readings. Explore options to shift energy use to benefit from cheaper rates (e.g., night rates) or integrate on-farm renewables. Understanding the breakdown of your charges is an important first step.
Variable speed drive
The decision of what size variable speed drive to install comes down to the effective lifetime of the unit, payback period for the investment and ongoing running costs. Consider installing a Variable Speed Drive (VSD) for the milk lift pump and for the rotary platform. Consider using a pump or flow controllers on water pipes, including the farm water tank. These measures can create energy savings, reduce breakdowns, extend pump life, and provide a more consistent flow. Installing a VSD allows the pump (water, milk lift, vacuum, etc.) to adjust to the system’s pressure demand, saving up to 15% in electricity. VSDs also help reduce animal stress during milking, lower somatic cell counts and minimise motor wear.
Effluent systems
Using a scraper on the backing gate can save water, energy and time. Explore alternative discharge/management options for water that doesn’t require effluent storage. These options are likely to be less energy-intensive by either avoiding pumping or reducing the energy needed to pump. Read more about how Taranaki Farmers achieved greater energy savings when upgrading their effluent system. Consider pond bacteria additive to shift operating costs to help reduce nutrient spreading costs, leading to lower overall input costs and decreased energy use.
Irrigation
Precision irrigation can achieve up to 50% water reduction, with energy savings as a by-product. Nanobubble technology can provide additional savings. If you use significant irrigation, assess your system to identify potential energy savings. Smart irrigation improves water use and stock health but planning for energy efficiency further increases your return.
Diesel
Consider where your feed is stored to save time and reduce tractor mileage. Plan multi-purpose trips to improve efficiency and conserve fuel. Use the smallest appropriate vehicle for the task. Regularly service tractors, check tyre pressures, and consider low-emission options. Assess whether using a contractor more often could help reduce fuel consumption and carbon emissions.
How to save energy when building a new dairy
When building a new Dairy, consider reducing your energy consumption for milk cooling, milk harvesting and hot water production. These factors provide the greatest energy savings:
- Milk cooling: Choosing an adequately sized plate cooler, double-bank plate coolers, cooling towers, and milk silo insulation wraps.
- Milk harvesting: Using variable speed drives for vacuum and water pumps, aiming for the shortest milking times possible. Use MaxT for efficient milking frequencies and strategies.
- Hot water: Optimise water-use and temperatures, off-peak heating, insulating pipes and cylinders, heat-recovery from the milk chilling system or solar water heating systems.
- Generators: Wiring a stand-by generator plug into the switchboard for significant power outages. This is much cheaper and easier to do when the dairy is built, than retrofitting.
- Location: Have you selected the best location for your dairy shed? Check the distance to electrical grid connection and road infrastructure. Assess the natural fall away from the site to allow effluent to flow into ponds without pumping. Take advantage of natural aspects for shade in hotter areas and sun in cooler areas.
- Construction: Have you optimised dairy shed design to take advantage of the surrounding environment. Assess ability to open up the shed structure for natural ventilation in summer and close up for winter heat retention. Use skylights or skylight wall tops to provide natural light. Consider insulation, especially under the roof and heat reflective cladding in warmer climates.
For more information visit On-farm dairy decarbonisation.
EECA case studies
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