Tauhara Geothermal Power Station

With our experience with past geothermal projects Bishops were selected by Fuji Electric to carry out the grouting of the power stations mechanical equipment. At 174MW nett output Tauhara boasts having the largest single shaft generator fitted to geothermal power station in the world. This plant is unique to New Zealand and incorporates two large steam turbines and one generator connected in series.  For structural stability the generator and turbines are bedded down with special grouts, for this part of the work Bishops poured a total of thirteen cubic meters of grout, permanent formwork was also required to be installed prior to the installation of the turbines and generator to prevent leakage of grout while pouring.

Other items that were grouted as part of the project included the following:

• 2 x condensers
• 2 x Hotwell pumps
• 3 x vacuum pumps
• 10 x other pumps
• 4 x scrubber vessel bases
• Main steam line supports
• Other piping supports

Overall, in excess of 50M3 of grout was installed over a 12 month period.

Other geothermal power stations that Bishops have been involved with are Mercury’s Kawerau (95MW output For Fuji Electric), Nga Awa Purua (145MW for Fuji Electric) and Nga Tamariki (85MW for Ormat Technologies) power stations and Contact Energy’s Te Mihi (2 x 85MW for Toshiba Energy) power station.

The scope of works for these plants was similar to Tauhara and also included foundation construction.