Small Hydro

There are already a number of small hydro schemes on rivers and streams around New Zealand, and there are many more
opportunities to use this energy resource to provide electricity to remote farms, homes and holiday retreats.

Most of New Zealand’s electricity is generated from hydro power stations. These generators convert the energy that is available in falling water into electricity. The water can either be stored in large lakes or dammed rivers (a storage scheme) before being passed through hydro turbines, or can be ‘run of river’ (without significant storage) where part of a river’s flow is passed through a turbine before being returned to the river.

These principles are the same, whether it is the Clyde Dam generating enough electricity for 250,000 houses, or a 1kW system suitable for one house.

Small hydro power schemes are generally classified into three size bands: micro-hydro is up to 10kW; mini-hydro is between 10 and 1000kW; and small-hydro is between 1000kW and 10MW. These may provide enough electricity for one house, a small village or a small
town, respectively.

Why use small hydro to generate electricity?

Using the energy available in falling water has a number of benefits. It can be converted into electricity that we can use in our homes, at work, or on the farm. Also, because it is a renewable energy source it does not release greenhouse gases into our atmosphere when electricity is generated. Typically, small hydro generation is located close to the end-user which reduces or eliminates transmission losses.

For New Zealanders who are concerned about rising electricity prices, or who are interested in sustainable and self-sufficient ways of living, small hydro schemes can be an attractive option. Because small hydro energy schemes often do not require dams or significant storage they can result in significantly less impact on the environment than large hydro schemes.