The potential of converting methane to energy and its ability to significantly reduce electricity costs and environmental impact was identified in the Southland Regional Energy Strategy.

To further explore this potential, Venture Southland invited NIWA, the National Institute of Water and Atmospheric Research, to present on methane recovery on dairy farms at the 2012 Regional Energy Conference and Workshop.

Later in 2012, to carry out a trial on the topic, a monitoring programme was established by NIWA on Glenarlea Farm in Dacre. The trial was very successful, producing more methane than what previous national models had forecast, and encouraged planning to commence in 2015 to build a fully integrated methane to electricity plant at Isla Bank. 

Following a successful pilot period, the methane recovery project was officially launched to the public in April 2017, showcasing how methane recovery helps to significantly reduce costs, harmful greenhouse gases and farm odour, while also helping farmers to produce NPK (nitrogen, phosphorus, and potassium) for fertiliser.

A video of the initiative was produced as part of ‘The Country Series’ by ASB Bank:

Glenarlea Farm's ongoing success

Following the initial methane recovery pilot, Glenarlea Farm, has continued to convert methane gas into electricity for the dairy shed, and to heat water for wash-down purposes on the farm.

The methane recovery system fuels a generator that produces 30kW of energy, with enough gas captured for the system to operate for up to 17 hours per day. It will remain operating at this rate until the vast amount of hot water created is able to be effectively utilised in meeting the farm’s energy needs, including powering an electric farm bike. 

The system has also been trialled in dairy farms in the Waikato and in Geraldine, and on a pig farm in Taranaki, but the Glenarlea Farm project is the southernmost application of the initiative.

The cost of implementing a methane recovery system varies depending on the effluent pond systems used, however, the savings able to be gained through generating electricity means the system eventually pay for itself, along with achieving many environmental benefits.

By identifying the potential to convert methane to energy on dairy farms, a significant step has been taken towards developing a cleaner more cost-effective dairy sector, not only in Southland but throughout the whole of New Zealand.