Energy Support for Dairy Farmers
The Challenge
Energy efficiency is often not top-of-mind for dairy farmers, who are typically more focused on immediate operational concerns such as animal health and nutrient management. As a result, investment in energy-saving initiatives tends to be low on the priority list. However, electricity costs for medium-sized dairy farms can range from $20,000 to $40,000 per year, making energy a significant - if often overlooked - operational expense.
In many dairy sheds, electric motors driving vacuum pumps are major energy consumers. These motors operate continuously to supply suction for milking. Other key energy demands include hot water for cleaning equipment and milk refrigeration systems. Despite their high energy use, many of these systems are not optimized for efficiency. Additionally, heat recovery systems are under-utilised, and farms often have suboptimal electricity tariffs or unnecessarily high-capacity connections.
The Solution
Thanks to funding from Fonterra and Nestle, Whirika conducted energy audits across 10 dairy sheds in Southland and Otago. These audits aimed to identify patterns in energy usage and recommend practical, cost-effective improvements tailored to each shed’s needs.
Key focus areas included:
Vacuum Pump Efficiency: Whirika assessed the performance of vacuum systems, including identifying excessive air leakage through bleed valves and recommending the installation of variable speed drives to control motor speeds more efficiently.
Hot Water Usage: Daily cleaning processes require large volumes of water heated to 85°C. Whirika examined the condition of water cylinder insulation and pipework to identify heat losses and ensure water use was aligned with regulatory requirements.
Milk Refrigeration: The audits evaluated how effectively milk was cooled prior to collection, inspecting heat exchangers, insulation on milk vats, and refrigeration systems to limit heat gain and reduce energy use.
Heat Recovery Potential: Many refrigeration systems produce waste heat that could be reused for water heating. Whirika identified that in many sheds, the infrastructure for heat recovery already existed but was disconnected or underutilized due to issues like pipe freezing and inadequate hot water storage.
Tariff and Supply Analysis: Whirika also reviewed electricity contracts and connection setups, identifying opportunities to switch to more cost-effective tariffs or consolidate supply points—such as combining the dairy shed and workshop connections—to reduce standing charges.
The first step to managing energy on farm is to understand where it is being used so our team took onsite measurements and nameplate data to develop a breakdown of energy use specific to the farm.
The Results
Whirika’s audits provided a clear breakdown of energy use for the farm with actionable insights into energy use across a representative sample of dairy farms in Southland and Otago. This allowed individual farms to compare their energy intensity against a database of other farms throughout New Zealand. This was a good first indicator for opportunity on the farm.
Farmers now have a better understanding of their key energy demands and the potential savings that can be achieved through relatively simple measures.
As a result of the collaboration with Fonterra and Nestle:
Practical recommendations were delivered to reduce energy waste in milking, water heating, and refrigeration.
Opportunities for utilising existing but inactive heat recovery systems were identified.
Several farms discovered they were overpaying for their electricity connections and could save money by renegotiating contracts or consolidating supply points.
These audits have laid the foundation for more energy-efficient dairy operations, helping farmers cut costs and reduce environmental impact without compromising productivity.