Friday, June 22, 2007

Wairau river hydro scheme approved

Trustpower's 72MW Wairau river hydro scheme has been provisionally granted resource consent. The scheme is a dog technically - an Aqua-style big, stupid canal diversion scheme with no storage capacity, in an area which is already subject to regular droughts, and which is expected to get significantly drier in the next fifty years as a result of climate change. And it poses some significant risks to the environment, notably to the habitat of the endangered black tern and to the general environment of the river itself. Braided rivers like the wairau need variable flows, and the worry is that the diversion will smooth them out too much. However, those concerns have been somewhat mollified with the conditions the Marlborough District Council have imposed, including that it have no significant impact on endangered species and that changes in river flows "be no more than what would occur naturally". A lot will hinge on the precise interpretation of the latter, and it may very well end up in the Environment Court, but at first glance if these conditions are actually met then I don't see any reason for the project not to go ahead. Other than the technological aesthetics, that is (really, hydro without storage? isn't that missing the point?).


Take your point, but it's better than a gas turbine. How do we generate power for a growing nation, and get to 100% renewables, without affecting local ecosystems - there has to be a trade-off somewhere and I can't see why this isn't a reasonable one.

Mind you, if the west coast glaciers retreat far enough, we'll be able to put big hydro dams in the glaciated valleys - like this one:

Posted by Rich : 6/22/2007 03:59:00 PM

Oh, its much better than a gas turbine, and if the conditions are met then it should be fine (essentially they're saying "you can do it, provided you don't have a significant impact on the environment". Which is pretty good IMHO).

And OTOH, its technologically ugly, grossly vulnerable to dry years and to long-term shiftsin climate, and overpriced. At the quoted project price of $270 million, they're paying ~ $3.5 million / MW. A windfarm costs only a third of that, for only a slightly lower capacity factor (50% vs 60%).

Posted by Idiot/Savant : 6/22/2007 04:20:00 PM

So, given that Trustpower is a commercial business, why are they doing this.

Is it too hard to find windfarm sites? (Do power generators have to find a willing landowner for their projects, or do they have a power of compulsory acquisition?)

Posted by Rich : 6/22/2007 09:53:00 PM

Rich: AFAIK they have to find willing landowners, unless the relevant local body gives them requiring authority (which has happened with the mid-Canterbury irrigation scheme, much tot he disgust of some of its intended victims).

But you'd think a 50km long canal scheme would require more land than a windfarm.

At the end of the day though, I don't really care, because its not my money on the line. If I was a Trustpower shareholder, though, I'd be asking some pointy questions.

Posted by Idiot/Savant : 6/23/2007 01:23:00 AM

maybe they are increacing their renewable energy / non renewable ration and are willing to take whatver they can get

Posted by Anonymous : 6/23/2007 09:12:00 AM