A Taranaki pig farmer who's pioneered the use of piggery effluent as an source of energy on his farm, expects the concept will spread as others see the benefits.
Steve Lepper who runs a 400 sow piggery, is the first in the pork industry to successfully develop a system that captures methane from covered effluent ponds and uses the biogas for electricity and heating.
In its first month, the system produced enough gas to cut daily electricity use in the piggery by 28%.
When fully commissioned, it's expected to save the farm more than $65,000 per year in electricity costs.
But Mr Lepper says it has even greater potential as a heat source.
The piggery is already using the system to heat four weaner rooms and eventually it will also heat farrowing rooms so the newborn pigs can keep warm.
Mr Lepper estimates a biogas system like his could cost about $100,000 to set up from scratch, but he thinks the energy savings are worth it.
Mr Lepper, who recently won an EECA energy award for his enterprise, says a number of other pig farmers are investigating biogas systems.
Pilot plants are also running on some dairy farms.