The three farming families living in the valley about 20km from Woodville are using a number of energy technologies installed by Industrial Research Limited (IRL) and Massey University to produce their own electricity to supplement the existing electricity network supply. 

“Other projects have looked at single-source generation mechanisms, things like solar or wind power but we think this is the first time that several different existing and next generation energy technologies can be found working together to produce a viable service,” said Alister Gardiner, manager of IRL’s Hydrogen and Distributed Energy Platform.

Called distributed generation, the project capitalises on the resources available in the farming environment - wind, sun and water.  Several years ago solar hot water technology was installed, along with a biodiesel generator and a microhydro system.

The most advanced development just introduced by Industrial Research has been the integration of a hydrogen energy system.  In this project, hydrogen is used as an energy carrier and for energy storage. The production of hydrogen requires an energy supply and at Totara Valley this is provided by a wind turbine. High up on a hill on Geoff Smith’s farm, the wind energy powers a water electrolyser which produces hydrogen fuel gas.

Using a concept called Hylink, the system pipes the hydrogen gas down the hillside to a fuel cell and water heater at the farmhouse in the valley below.  As well as transporting the energy, the Hylink system stores hydrogen in the pipeline so that a supply of energy can be maintained even when the wind is not blowing. For this demonstration the 2km long 18 mm diameter plastic pipeline holds about 5kWh of hydrogen energy storage and can be easily scaled up for larger energy needs.

The fuel cell converts the hydrogen fuel gas and oxygen from air into electricity and heat, with water as the only by-product. It is much cleaner, quieter and more efficient than a generator, and the heat can be used to produce hot water if it is convenient to do so.

The next stage of the project to be completed this year is to inject increased energy at the three farms in order to demonstrate the concept of a small microgrid at the end of the network.  Load analysis has shown that each of the three farms must be able to generate about 6kWp of electricity daily for the community to be self-sufficient.

The key concept to be demonstrated at a very preliminary level is that a microgrid could have no technical need for a central supply or a supply industry.  At present, however, there are market design and regulatory issues associated with community sharing of locally generated power and reliability problems around the disconnection of a community from the network.

Alister Gardiner says that generally the power industry is supportive of distributed generation and keen to understand its potential role.

“Their view  seems to be, however, that any electricity that leaks onto the network locally should be treated exactly the same as electricity which originated hundreds of kilometres from the point of use, and that it should be effectively sold through the wholesale market. This is a complex topic, but for the customer benefits of distributed energy to be realised, new thinking is required.

“I believe there is also a strong argument for early market encouragement to support the public good benefits of local generation, which are otherwise not captured.”