Genesis Energy : invests $15m+ on Tekapo B upgrade

11 October 2021

Genesis Energy has started stage two of a challenging four month, multi-million-dollar upgrade of its Tekapo B power station to deliver substantial efficiency gains and future proof the power station for decades.

The $15 million+ project will see the station deliver its 800 GWh of annual generation by using up to 12,000 less litres of water per second. The work involves installing new turbine runners, and refurbishment of the generators, headgates and transformers. Other upgrades including the generator protection system and penstock flow measurement system will also be undertaken during the outage.

The project has taken five years of planning, design and manufacture with key partner Andritz Hydro.

Chief Operations Officer, Nigel Clark, said in addition to the efficiency gains there will be improved operational flexibility along with reduced running limitations and annual maintenance costs.

"When doing large projects like this we always have an eye to the future," said Clark. "Our approach is to look at the surrounding plant and see what else can be done to improve overall performance, generation and increase the availability of the unit to the market. This current work will also future proof the station to give us the ability to increase the generation potential of the Tekapo Scheme as other components are progressively upgraded."

The turbine runner is a crucial component that drives the generator. Replacing it requires the dismantling of the generator and turbine components - one of the biggest tasks of the project. The 15m variability of Lake Pūkaki's levels posed some design challenges, but the new flexible, more efficient runners will be able to handle a wider operating range.

The work follows the completion in February of a two-year $26.5m project to install a new intake gate at Tekapo A.

A time-lapse video of the turbine being lifted out for dismantling can be seen here

The Tekapo Power Scheme has been owned and operated by Genesis since 1 June 2011.

The 190MW hydro scheme is located at the head of the Waitaki Valley in the Mackenzie District of the South Island. Water is taken from Lake Tekapo through an intake tunnel and generates electricity through Tekapo A Station (30MW). Outflows from Tekapo A travel down the Tekapo canal before entering Tekapo B Power Station (160MW) to be used for generation a second time. Tekapo B sits in the bed of Lake Pūkaki, with outflows entering the lake directly.