Common high demand times were 6am to 9am and 6pm to 9pm.
There were also other events Transpower knew would cause high drain on the system, and it advised participants in the demand response scheme of those via phone app.
Participants could then choose to switch off some of their load during those times or use standby generators, batteries or other power sources. In return, they received a payment from Transpower.
While there were some "really good impacts'' by some big businesses, oddly, farmers - particularly dairy farms with irrigation who were high energy users - had not got involved in that.
The question was "why'' as it seemed to be "a bit of a no-brainer'', she said.
PhD student Jefferson Dew was examining what farms could gain by joining demand response schemes such as Transpower's, or actively managing their demand according to electricity markets and distribution pricing and also learning more about what social and other barriers prevent farmers from making changes to the operation of their farms.
He was working with two clusters of dairy farms that were operated by iwi in both the North and South Islands.
Each of those farm clusters included up to a dozen high-tech, irrigated dairy farms that manage about 900-1200 cows each.
Power chewed up about 5 per cent of operating costs on each farm.
In some areas where there had been a lot of new dairy conversions and irrigation go in, lines companies had difficulties with congestion, Stephenson said.
There was so much draw-down on electricity at times that the lines sometimes could not cope. That was a big issue for lines companies and Transpower in those parts.
Solutions did not need to be immensely complicated; it might be as simple as automatically turning off irrigation for 30 minutes at times of peak demand, she said.
Dew, who was heading to Europe soon to speak at a conference about the work being done, said dairy farmers might not be able to change milking time, but increasingly farms used a lot of power for things such as cooling, sterilising and irrigation.
It could be manageable to do those things at different times, avoid the peak power consumption periods and make back some cash without disrupting farm processes.
They were also looking at what simple tech solutions could be developed so the timing of activities could be flexibly and automatically changed, without farmers being inconvenienced by having to switch things on or off.
When he returned, he would present his findings to the iwi, showing both the technical potential and practical ways that farmers could manage it.
Stephenson said it was hoped that, as long as there was no risk, the team could show the real potential of it and, ideally, farmers around the country might realise it was something they could get involved in.
If they had the right mix and the ability to be flexible, there was possibly an opportunity to save money on-farm, while also contributing to something "much bigger''.
"The evidence is just coming together now about how significant it could be and it's going to be really exciting to see how farmers start to respond to that,'' she said.
Globally, very little has been done on the idea but there was a lot of interest in the potential financial benefits for farms by making some adjustments in the timing of electricity use.
Preliminary results would be shared with the iwi and then be published more widely, she said.
