Hydroelectricity has been the backbone of New Zealand's electricity supply system for decades, and hydroelectric dams are a well-known feature of the New Zealand landscape. New Zealand generates more than 50% of its electricity from hydro generation, much of it through large hydro dams such as Benmore, Manapouri, and Clyde.
Benefits of hydroelectricity
Hydroelectricity produces no greenhouse gas emissions in its operation, and water stored in a dam can be turned into electricity at short notice. This makes hydro an excellent complement to wind power, which is intermittent.
However, hydroelectricity is subject to the weather and New Zealand's heavy reliance on hydro has been exposed in past ‘dry winters' when hydro storage (lake levels) has dropped, requiring careful management.
The potential for micro and small-scale hydro energy in New Zealand
Most new hydro developments being proposed in New Zealand are relatively small scale. In some cases the capacity and efficiency of existing hydro schemes can be enhanced to increase generation output.
"Small hydro" refers to projects below, roughly, 10 MW (megawatts) in capacity. This includes micro-hydro, which is usually less than 10kW and is used on domestic applications.
There is currently over 160MW collectively of small hydro schemes (of a size less than 20MW) already installed in New Zealand (enough to provide electricity for over 80,000 houses). The potential for additional small hydro generation capacity is substantial.
Small hydro schemes are a means of providing electricity to remote farms, homes and holiday retreats, or for selling electricity to other users or into the electricity market.
There are a number of competing interests and values associated with use of water in rivers and lakes and these need to be considered when assessing opportunities for further development of hydro schemes of any size. But because small hydro energy schemes often do not require dams or significant storage they usually result in significantly less impact on the environment than large hydro schemes.
Supporting hydro energy in New Zealand
EECA works to remove barriers to, and encourage the uptake of, all renewable energy technologies. This includes providing independent and impartial information, and in some situations supporting projects through the Resource Management Act consenting process. Find out more about EECA's role in promoting renewable energy.
EECA provides resources for local government to help develop renewable energy in New Zealand, including assessments of regional renewable energy potential.
EECA also raises awareness of the benefits and costs of distributed generation, and provide financial assistance to assist with the completion of feasibility studies for potential distributed generation projects.