Independence
Day

Will alternative power sources allow farmers to freeÊthemselves from depending on the national grid?

If the weather were better, Phil would be able to see the wind turbines of the Tararua Wind Farm turning in the far distance. Maybe, he thinks, some day a smaller cousin of one of those wind turbines will stand where the anemometer now does. Maybe the farm's gravity-fed watering system will power a small hydro-electric generator.

The 'maybes' matter. From 2013, electricity line companies will no longer be obliged to mend or maintain lines to uneconomic areas, and it will fall to the landowner to pay for maintenance or reconnection costs. When that happens, the trade-offs between buying in power and generating it yourself will have financial consequences.

Farmers like Geoff Smith need to know exactly what those trade-offs are before they make their choices. How much power do their farms use and when? Can other sources of power be found? What are the relative costs?

For almost a year Institute of Technology and Engineering students Phil Murray and Glenn Irving have been working with farmers to gather data about electricity consumption on three farms in the remote Totara Valley. "Without absolutely accurate data about present electricity consumption and the seasonal variations in the profile of consumption, you don't know what generation capacity you need," Phil says.

It turns out that except during the shearing season the power consumption is meagre. In fact, farmers pay more to maintain the power supply (line charges) than they do for the electricity. "You're looking at a situation where they might pay line supply charges three to four times the value of the electricity used," says Phil.

Could on-the-farm generation meet the need? On Geoff Smith's farm, the wind run figures collected by Phil from several promising sites are one of the measures that will help supply the answer. "You need wind run figures all year round, the high wind months as well as the still months," says Phil.

Down in paddocks on the Skerman farm, blissfully out of the wind, is Rachael Boisen. Rachael is working towards a Bachelor of Applied Science (honours) degree in natural resource management; her final year project will examine the legal requirments imposed by the Resource Management Act on farmers wanting to set up alternative power sources. Today, though, is a day for getting the hands dirty and the feet wet hunting for possible hydro-power sites on the meandering Totara Stream.

There are several options: diverting some water flow directly through a small hydro turbine, building a weir to increase potential head and capacity, or using an existing gravity-fed domestic and farm water supply system system."

One site in particular beckons: a wide oxbow where the stream bed loops back on itself. Between the upstream end of the loop and the downstream end is a three-metre drop. This is a perfect place to run a pipe and install a small turbine. And the site is close to the house and the woolshed.

Again, records will need to be kept to find out the site's potential. "You need stream water level figures during the winter and spring peaks, as well as the summer dry spells. You need to factor in what would happen in a drought, or during prolonged calm periods," says Phil Murray.

Farmer Geoff Smith welcomes the University's interest. "It may seem some time before 2013, but people in remote areas need to start planning now. A lot of farming is based on reliable electricity supply - shearing, fencing, freezing - and the loss of it is a worry always in the back of your mind."

Associate Professor Ralph Sims, who is supervising the projects, says that regardless of changes to the electricity industry, or likely advances in technology - such as more affordable fuel cells -Êsmall-scale, renewable resource energy generation is the way of the future.

"I doubt we'll ever see large monoliths like the South Island's hydro-electric power stations built again. The future lies in mixes of small-scale power production units making enough electricity to serve their communities, with any excess being fed back to other cosumers in cities or towns."

Phil Murray predicts some fortunate farmers, like Geoff Smith, will one day find that windy ridge line up the way or the stream by the woolshed has a monetary value. "Not every farm has windy ridges, or a stream with enough fall. In future these resources will add value to farms."

Phil Murray's project includes similar studies for comparison purposes at Limestone Downs station near South Auckland, supported by the C. Alma Baker Trust. Industrial Research Ltd has supplied electricity profiling meters and technical backup on power quality control at Kumeroa, Limestone Downs and D'Urville Island. The Central Power Trust had the foresight to support the work in the first instance, and Powerflow Technologies worked closely with Glenn Irving to develop a decision-making model for use by communities. Phil Murray's work is supported by Meritec Consultants' Jim Fletcher Scholarship.