Potential pumped hydro sites | Image: Australian National University
Researchers at ANU say 22,000+ potential pumped hydro sites they have identified across Australia represent storage capacity of 67,000 gigawatt-hours (GWh), far more than the nation requires to support a reliable 100% renewable energy based electricity system.
Only a very small amount of this potential would be needed to be used according to lead researcher Professor Andrew Blakers from ANU’s Research School of Engineering.
“Australia needs only a tiny fraction of these sites for pumped hydro storage – about 450 GWh of storage – to support a 100 per cent renewable electricity system,” said Professor Blakers.
This translates to only the best 0.1% of the sites being required.
The tally has grown dramatically since ANU announced 5,000 potential sites in an earlier report on its preliminary findings.
Professor Blakers says developing a small number of the most promising sites by 2022 could address challenges posed by the closure of Liddell Power Station and other coal-fired generators.
Pumped hydro storage involves using surplus, off-peak electricity or renewables based generation to pump water from a lower reservoir to a higher one. When electricity is needed, water from the top reservoir is released, runs through turbines to generate electricity and is discharged into the lower reservoir.
The following table indicates resource estimates in each state/territory:
| Sites | Energy storage (GWh) |
|
|---|---|---|
| NSW/ACT | 8,600 | 29,000 |
| Victoria | 4,400 | 11,000 |
| Tasmania | 2,050 | 6,000 |
| Queensland | 1,770 | 7,000 |
| South Australia | 185 | 500 |
| Western Australia | 3,800 | 9,000 |
| Northern Territory | 1,550 | 5,000 |
| TOTAL | 22,000 | 67,000 |
Detailed maps showing the location of the potential short-term off-river pumped hydro energy storage (STORES) sites can be viewed here.
The research involved searching for sites where pairs of dams with an altitudinal difference of more than 250 metres could be established. It excluded residential areas, national parks and other locations considered sensitive. Each site identified has between 1 gigawatt-hour and 300GWh of storage potential.
In an article published on the Australian Renewable Energy Agency’s (ARENA’s) web site, Professor Blakers said pumped hydro could help support the approximately 3 gigawatts of wind energy and solar power capacity currently being installed per year in Australia.
“If this continued until 2030 it would be enough to supply half of Australia’s electricity consumption. If this rate is doubled, then Australia will reach 100% renewable electricity in about 2033,” stated the Professor.
The ANU’s research was supported by ARENA.
In February this year, ARENA and the Clean Energy Finance Corporation announced they would be prioritising financial support for flexible capacity and large-scale energy storage research and development..
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What do the researchers at ANU say about the cost of this approach? Apparently nothing because the article doesn’t once mention the word “money”.
I conclude from this that it is economically non-viable and will require billions of dollars of subsidies.
Thanks Michael for your comments on this important topic.
The Australian pumped head energy storage estimate of 67,000 GWh refers of course to the estimated cumulative “power generation output part” applicable to these closed loop hybrid generation solutions; but you have not mentioned the important counterbalancing cumulative “power consumption input part” relating to the pumped head requirements for the closed loop to function as intended.
Are you able to put forth some comparative values to the “power generation outputs” verses the “pumped head power consumption inputs” equation, to add some clarity to the relative effectiveness of closed loop hybrid pumped head generation solutions please?
Lawrence Coomber
We have a pumped hydro storage here in southern Queensland (Splityard Creek) based on a small dam above the massive Wivenhoe Dam which supplies most of Brisbanes water. CS energy claims it can supply 500MW for 10 hrs (ie 5,000 MWh capacity) before the storage dam has to be refilled- obviously usually at night. I think the facility is under utilised probably because it is cheaper and uses less coal to just supply the extra power from our power stations when that is available ie just use the pumped hydro when absolutely necessary. As far as efficiency it is hard to get accurate figures but a realistic figure would be a little over 80% for each cycle (pumping up and generating) so an overall efficiency of about 66%. This means you have to use 50% more coal or gas to supply the same amount of energy using the pumped hydro- not a good look! Obviously it would be a different story if the pumping was done by large scale solar or wind.
The whole power story and the politics and misinformation has me fascinated. As one who has lived on solar and off the grid for a short time (my present wife did it for over 30 years!) I can put the whole story in 10 words. Are you ready?
Renewable, continous, cheap. With power you can have any 2!!!
The exception should be Denmark etc who can access Norway’s hydro when the wind doesn’t blow. But that’s another story.
Glad to recieve any corrections.
Cheers
Bob
Wivenhoe’s pumped storage apparently is not being used to lower electricity prices for Queenslanders:
http://reneweconomy.com.au/wivenhoe-pumped-hydro-big-little-plant-didnt-30606/
If its round trip efficiency was only 66% I would be surprised. Pumped storage is more typically around 76% efficient.
I have dug up an ancient document from the 80s that says Wivenhoe’s pumped storage uses slightly less than 4 kilowatt-hours to generate 3 kilowatt-hours on page three:
http://www.floodcommission.qld.gov.au/__data/assets/file/0007/7792/Tarong_Energy_Appendix_11.PDF
That would be an efficiency of 76% or possibly more.
From that article-
‘In calendar 2016 Wivenhoe produced 114 GWh and used 172 GWh in pumping. That’s an efficiency ratio of 66%.’
As I said-
‘Provided the lights aren’t going to go out CS Energy makes more money running coal than Wivenhoe.’
Not surprising to see that the QLD state government was accused of ‘gaming the system’ to help it’s budget.
Also-
‘because the pumping comes from coal powered generation its actually carbon inefficient to run.’
So, very interesting to see how we can reach the proposed target of 50% renewable power by 2030 and what part pumped hydro like Splityard Creek will play.
Thanks Ronald.
Yes I have seen that document but it’s hard to dismiss the actual power out/power in x100 value you get from their own figures.
I think its real value might be in the future to stabilize large scale solar or wind power inputs (essential if the state is to get into renewable power). Here it would operate in ‘synchronous condenser mode’ where it can change from spinning reserve to pumping or generating mode in less than 20 seconds. I cannot find if it is run in this way at the moment; probably no need. Any info on this?
Hydroelectricity is often used to provide ancillary services to stabilize the grid, so I presume they would often use the generator as a synchronous condenser so they can quickly provide extra power to the grid or provide a load as necessary. But I’m afraid I don’t actually know if this is the case at Wivenhoe.
Providing ancillary services may have something to do with why its efficiency appears so low, but that’s something I’d have to look into. (And I’m not going to look into it. Not at the moment anyway.)
I’m very interested in finding out more information on small-scale Hydro storage as the idea has been on my mind for a number of years now and I haven’t seen a lot of information about it. I’ve done a few searches but invariably end up . We have a small 70-acre hobby farm in the Hunter Valley NSW, the land is undulating and includes a reasonably steep hillside.
Now, a number of commenters here have stated the likely round-trip efficiency of hydro-storage, with results that I believe are far better percentages when compared to the current feed-in tariffs versus the cost of grid-supplied power.
We currently have 12kw of solar panels on our roof (6kw facing East, 6kw facing West), half of each side independently supplying 2 x 4kw inverters that produce a combined yearly average of approximately 60kw a day. We aim to add battery storage in the near future, although hoping a storage subsidy comes into play soon as well as wanting to see what the next iteration of the Powerwall brings. Based on our current usage we would require approx. 30kw of storage to get us through a winters night.
As an alternative to multiple Powerwalls, I’ve been thinking about a single Powerwall combined with a hydro storage solution powered by excess solar production and off-peak electricity to compensate for our peak electricity usage times as follows:
Two x 25,000-litre water tanks as top and bottom reservoirs, with the top tank approx.+50metres in elevation at 500mtrs distance away.
My question is, does anyone have any idea how to calculate how much energy storage this will provide, what pipe size would provide the best power output and is there any advantage in running different sized pipes over differing distances to increase efficiency (i.e. shorter larger diameter to supply top reservoir and longer smaller diameter to supply the turbine – say 350mtrs long x 75mm supplying top, and 700mtrs x 50mm to turbine and bottom reservoir. Any advice would be appreciated. Cheers, Jay
With a 50m drop, frictionless pipes, and a 90% efficient generator you would need 8.2 tonnes of water to generate 1 kilowatt-hour of electrical energy. I assume friction would be significant for 500m of piles with a relatively gentle slope. A frictionless pipe would only have to be cm in diameter to generate 1 kilowatt of electrical power but I hear the entire supply has been used to make problems for physics textbooks. With friction, which is too complicated for me to work out, things will be considerably worse. I don’t think this would pay for itself on such a small scale even if you had existing reservoirs.
Jason you have options to upgrade your energy generation strategy taking a longer term view, but from what you have described about your property a closed loop pumped hydro resource is definitely off the books for you.
For any form of small scale hydro to be considered as a commercially viable energy resource, certain stars need to line up, and as a minimum: having unrestricted access to a flowing river or stream sufficient to exploit gravity and the kinetic energy available in running water through one of several small scale hydro solutions is a must have.
This is a key point and not often found when undertaking energy independence surveys for customers, but if available it is an exciting find to exploit for sure.
Pumped hydro though is not a cost effective solution in your case and the pendulum swings sharply in favor of battery storage over the pumped hydro idea.
Battery storage opens up more opportunities for you than you have described also Jason. Best energy solutions design practice capitalises on leveraging the most cost effective energy resource as the primary that everything else is integrated with and in your case that is solar PV of course.
You only have to add about another 6 kW of solar to your existing 12 kW and you have a very useful and reliable DC bus supporting a substantial single inverter 3 phase fully featured off grid solution with the addition of suitable sized DC coupled battery storage stack. Further you can simply add any other PCE directly off the DC bus including a VFD (variable frequency inverter) to seamlessly power all of your property and household water pumping requirements.
Going this route you also are eligible for STC’s for your additional solar PV system.
Stay focused on design efficiency and simplicity. Higher voltage lower current systems are modern designs with many technical; functional, and safety advantages over the older ELV designs. Treat the whole exercise as a simplified modular energy engineering project of high reliability, endurability, and functionality moving forward.
And all the best with your energy independence in the future Jason.
Lawrence Coomber