Quote Originally Posted by teabag View Post
Does anyone know rough figures for the efficiency of the Onslow scheme - In the sense of the ratio between running the surplus water directly through a generator, compared to pumping it to Onslow and then out again?
Yes, I can answer that. The Roxburgh generators are currently 90% efficient, but that will increase shortly due to new runners being installed in 4 of the 8 generators. New average efficiency is likely to be 91%. K14 may be able to give better numbers on that if he sees this post.


Depending on whether Onslow uses variable speed turbines, reversible turbines, or fixed pump turbines, Onslow will be around 88% pumping and 91% generating for a combined efficiency of 80% in the best case or around 75% if the cheapest option is taken. This decision would be part of the $70 M investigation.

Of course I am pushing for the most efficient variable speed, reversible turbines.