My Queen’s Birthday weekend was spent in the Victorian high country, visiting, amongst other things, the Mount Benambra which provides the title of my personal blog. While the view remains gorgeous, the fact that it was 11 degrees Celsius on a winter’s day at 1400 metres above sea level was pretty disturbing. The high country is suffering from the effects of climate change. It’s playing a small but fascinating part in doing something about it as well.
The Kiewa Hydroelectric Scheme was constructed over an extended period through the 1950s. It’s not large, with a peak capacity of only 241 megawatts, dwarfed by the brown coal behemoths of the Latrobe Valley. But it’s substantially smaller than it was originally intended. The recession of the early 1950s, and Ming’s decision to prioritize the Snowy Mountains Scheme, saw the original plan for a power station at Bogong Village, on the road to what’s now the Falls Creek ski resort, cancelled. More than 50 years later, the unfinished scheme has been revived, thanks to the various renewable energy targets floating around. AGL is spending $230 million to build the Bogong Power Station.
While every energy source has an environmental impact, this is about as benign as you can get. It’s making a bit of a mess in the valley at the moment, but the area affected is really tiny, as you can see from the photo. It hasn’t resulted in any new dams being built; the output of the Mackay Creek power station, 400 metres further up, is fed directly into an underground tunnel which runs into the new power station, which discharges into the existing buffer dam at Bogong Village.
How much energy will this plant produce? It’s rated at 140 megawatts, peak, but there’s not enough water available to spin the turbines continuously. It’ll be used for peak-period generation; on average, it’ll generate about 94,000 megawatt-hours of electricity every year. That, my friends, is the equivalent of the output of 50,000 of the dinky little rooftop solar panel setups I can no longer get a subsidy for - and keep in mind that the government was only ever going to fund 6,000 of them. And it’s even more valuable to AGL because it can produce electricity precisely when the price is at its highest.
Like the title says, this may well be the last substantial hydroelectric plant ever constructed in mainland Australia; there’s very few spots left with substantial hydro potential that would ever get environmental approval. But, in a broader context, it’s an example of the likely earliest responses to the emissions trading scheme - not particularly glamorous, in many cases using familiar technologies, and almost invisible to the general public.
Feel free to delete the pedantry.
I’ve wondered in the past why more power stations don’t re-use the still-perfectly-good water a bit further down the hill. Seems they’re doing it here!
There’s been a bit of a debate about whether hydro plants are actually that CO2 emission friendly - IIRC something to do with the methane given off by large amounts of rotting vegetation in the catchment areas as the water levels change.
“The amazing stuff about this is that you can play 36 holes on it in the afternoon, take it home, and just get stoned to the bejesus belt that night.”
Oh, not that kind of hydro.
Australia used to be dotted with mini hydro-electric plants didn’t it? There’s at least one unused one near the coast not far from here that used to power Gosford as far as I know - most of the environmentally impactful stuff (like dam and lake building) has already been done, the turbines and generation equipment would need replacing though.
It’s not quite that vision of 20 Nuke plants up and down the coast, but it might help.
Chris: I’ve wondered about this as well.
It apparently depends a heck of a lot on whether you’re flooding tropical rainforest to build a dam. This is particularly an issue in Brazil; not so much in temperate climates like southern Australia.
In this specific case, no new dam has been built, so it’s not an issue.
David: yes, there’s a lot of dams which could probably be fitted with small hydro plants. For instance, there’s been a project to fit a regulating pondage at Dartmouth Dam - actually visible from Mount Benambra, funnily enough - with some new turbines, a two-megawatt jobby that runs all the time, and two five-megwatt ones that run at high-flow periods. The question will be whether it’s worth running power lines to the grid to transmit the generated electricity, I suspect.
Good old Kiewa/Bogong! Thanks Robert!
the fact that it was 11 degrees Celsius on a winter’s day at 1400 metres above sea level was pretty disturbing. The high country is suffering from the effects of climate change.
Robert you can go back to being your usual undisturbed self. 10 cm of snow in the high country including Falls Creek - just up from Bogong Village. Lesson:Weather is variable
Chrisl: I’m not claiming that we’re all going to die based on one unusually warm day.
That said, it was one unusually warm day in a decade of unusually warm and (particularly) dry temperatures in the Victorian Alps.
Robert: North winds - warm weather possibly up to 11 degrees
South winds - cold weather possible snow.
Apart from the climate change reference it was an interesting post.Ironic that the whole Keiwa scheme would not be remotely consiered to be built today.Easier to build a desalination plant.
I looked up the averages and for Bogong. The mean max for June is 10.3, whereas for Falls Creek it’s 2.8.
There are no observations for Bogong that I can find, but the mean for Falls Creek this June has been 6.5.
The observations for Falls Creek for May were pretty much spot on the mean.
So my conclusions are:
The weather in that part of Victoria seems to have been unusually warm for June so far, but it’s early days.
Robert was possibly not as far up into the cool air as he thought he was.
chrisl is being a pain.
Ooooo I have to boast that I have been peripherally involved with this project for the last few years.
It’s even better than Robert describes; reusing the water by running it through a tunnel and then feeding it into the bottom of Lake Guy will restore the river upstream to more normal flows. At present, water levels vary according to power output - so it can rise and fall by up to two metres a day, which has obvious problems for the establishment of streamside vegetation, downstream fishermen, etc.
And the rock from within the tunnel is being used as a base for the Bogong High Plains road, which will help protect the fragile alpine environment this traverses.
Interestingly enough, on a tour of the facility, one of the board members said this and several similar ‘clean energy’ proposals had gone to the board several years ago, with the explanation that spending these millions would clean up the environment.
When the directors heard that spending this money would not result in any profits to the company, they laughed.
Now there’s a direct benefit to them, so this and similar projects are getting the go ahead.
I was also involved in this at the far margins - helping to get the rubble waste from the tunnel to be used to seal the high plains road.
Regarding carbon emissions - yes as robert says, it’s a matter of where - tropical vegetation for some reason rots as methane underneath the water for up to 50 years after flooding. Not nearly such a problem in temperate areas.
My understanding of the reason the system is smaller goes back before the 50s. It was closely considered in the 20s, but John Monash thought brown coal was a far better bet, and he had the last word.
“That, my friends, is the equivalent of the output of 50,000 of the dinky little rooftop solar panel setups I can no longer get a subsidy for - and keep in mind that the government was only ever going to fund 6,000 of them.”
Sounds worthwhile. Thnx for the info Robert. You’re doing a good job filling us in on all these enegy-generating schemes. Certainly helps give a rounder picture of the energy situation. I’m pleased a few people have got solar panels, just in case of emergencies. And they can feed back into the grid eventually. But it does seem that resources for them are getting scarcer…at least for the older models.
I still like your idea of shifting the solar focus to larger buildings…such as pools, community centres…& of course schools (a Labor initiative). It’s hilarious to listen to the Coalition griping when they did sweet f all until the last coupla years, when under pressure from the polls. And didn’t they take credit for a number of State initiatives? Perhaps you can clear that up.
Brian: Mount Benambra and Bogong Village are two different places, about 40 kilometres apart as the crow flies. Bogong Village is at about 800 metres altitude, the summit of Mount Benambra is about 1400.
And, frankly, Monash was probably quite right at the time. While we can blame John Howard for ignoring greenhouse science, I think Monash gets a pass…
Thanks, Robert. I should have re-read your first sentence.
Robert, I used to own a block of land at Tawonga South, so I know the area well. Lets hope the “mess in the valley” is only temporary.
Carbonsink: I remember Paul Clitheroe of the Money program standing in front of a house and saying “welcome to my worst investment ever” It was a block he bought with mates in Tawonga Sth
It really is a pretty small mess.
And the vegetation in that area does tend to recover (unlike higher up, which takes a long time to grow back). There’s a walking track in the area which shows this pretty dramatically; one side of the track got burnt in the 2003 fires and the other side didn’t. You can tell the difference, but you have to look pretty hard.
Obviously, at the hydro plant the trees have been completely knocked down, but I’m pretty confident the area will recover well.
I remember selling mine for a tidy profit. Mind you, it was a very long time ago when blocks of land sold for 5 figures not 6.
Robert, so is the hydro plant just downstream from the village and the little lake?
It’s customary to rate hydro power station capacity by it’s “head” pressure. That is a combination of two things: one) how far the water has to fall from the intake penstock down to the scroll case underneath the generator where the water drives the impeller; and two) how much water there is to fall.
In short: the more the water, the higher the dam, the greater the MW output.
If you can think of a place in Straya with a lot of water and a long water drop, that would be a good place to build a hydro plant. Otherwise it’s a case of building a lot of smaller ones, which as Robert says, is unlikely.
Regarding power generation below an existing hydro plant. That is possible if there is a lot of water coming out of an existing generator combined with a steep enough grade to maintain the inertia contained in the water. The trouble with that set-up is if you lose flow through one generator, you lose it in both. You need a way to store energy, hence Rob’s Bogong “buffer” dam. But all that takes a lot of drop and a lot of water. The simplest way to achieve a series of hydro plants is this: get bigger mountains.
carbonsink: directly below the village, with the water discharging into the little lake.
It’s worth noting that Norway is planning to make hydro the capacitor that allows wind-power to provide reliable base-load: when the wind blows, the water is pumped uphill into the dam, so the energy is stored until needed. Smart synergy!
Mind you, you’ve got to actually have some water in the first place - something droughts make difficult.
Robert said:
I think the claim in this case was it is a continuing problem after the dam has been built due to the significant changes in level of the dam cyclically converting vegetable matter to methane. I’m a bit skeptical given that growing the vegetation in the first place should act as a carbon sink, but then methane is meant to have more impact as a greenhouse gas than CO2 so perhaps it is true.
It has been a warm June so far in the high (and not quite so high) country, in Canberra this year the June average maximum has been 14.8C, compared with a mean since 1974 of 12.3C; the June average minimum has been 5.8C, compared with a mean of 1.4C.
A few months ago I went to a public lecture where it was stated that much of the reductions in emissions in the first phase of the EU ETS were from a switch from brown coal to black coal, with brown coal fired power plants being turned off on the weekends. I suspect that even a modest carbon price will lead to significant reductions in emissions from changes in how the national electricity market works.
Very true, Peter, but that possibility is causing fairly serious angst in Victoria and South Australia… :/