Deep South Series: Lake Onslow hydro plan- energy saver or white elephant?

The Herald is proud to present the third episode of a major new investigative documentary series Deep South produced and presented by Crux Productions.

The Government is spending over $30 million in planning for one of NZ's biggest ever construction projects – the $4 billion pumped hydro scheme at Lake Onslow, south of Alexandra.

In 2020 the Government initiated a feasibility study into a pumped hydro storage project at Lake Onslow.

Something like Onslow would provide the opportunity to fill up when it is wet and blowing, and produce energy when it is dry or not blowing.

The concept of Onslow is to provide power through a dry year in the absence of fossil fuels. While coal has served New Zealand well, if Huntly Power Station was to wear out, Onslow would provide protection and security of supply for our modern societies that are built around readily available electricity.

If built it will be bigger than all of the country's existing hydro schemes put together, and could help deliver 100 per cent national sustainable electricity.

But is the financial and environmental cost worth it, and why are some of the biggest electricity generators so against it?