Three researchers from Australian National University have conducted a study into the possibility for new pumped hydro storage capacity in Australia – with remarkable results. They have identified more than enough sites to provide all the energy storage Australia needs for an energy system based on renewables. Courtesy The Conversation.
The race is on for storage solutions that can help provide secure, reliable electricity supply as more renewables enter Australia’s electricity grid.
With the support of the Australian Renewable Energy Agency (ARENA), we have identified 22,000 potential pumped hydro energy storage (PHES) sites across all states and territories of Australia. PHES can readily be developed to balance the grid with any amount of solar and wind power, all the way up to 100%, as ageing coal-fired power stations close.
Solar photovoltaics (PV) and wind are now the leading two generation technologies in terms of new capacity installed worldwide each year, with coal in third spot (see below). PV and wind are likely to accelerate away from other generation technologies because of their lower cost, large economies of scale, low greenhouse emissions, and the vast availability of sunshine and wind.
New generation capacity installed worldwide in 2016. ANU/ARENA, Author provided
Although PV and wind are variable energy resources, the approaches to support them to achieve a reliable 100% renewable electricity grid are straightforward:
- Energy storage in the form of pumped hydro energy storage (PHES) and batteries, coupled with demand management; and
- Strong interconnection of the electricity grid between states using high-voltage power lines spanning long distances (in the case of the National Electricity Market, from North Queensland to South Australia). This allows wind and PV generation to access a wide range of weather, climate and demand patterns, greatly reducing the amount of storage needed.
PHES accounts for 97% of energy storage worldwide because it is the cheapest form of large-scale energy storage, with an operational lifetime of 50 years or more. Most existing PHES systems require dams located in river valleys. However, off-river PHES has vast potential.
Off-river PHES requires pairs of modestly sized reservoirs at different altitudes, typically with an area of 10 to 100 hectares. The reservoirs are joined by a pipe with a pump and turbine. Water is pumped uphill when electricity generation is plentiful; then, when generation tails off, electricity can be dispatched on demand by releasing the stored water downhill through the turbine. Off-river PHES typically delivers maximum power for between five and 25 hours, depending on the size of the reservoirs.
Most of the potential PHES sites we have identified in Australia are off-river. All 22,000 of them are outside national parks and urban areas.
The locations of these sites are shown below. Each site has between 1 gigawatt-hour (GWh) and 300GWh of storage potential. To put this in perspective, our earlier research showed that Australia needs just 450GWh of storage capacity (and 20GW of generation power) spread across a few dozen sites to support a 100% renewable electricity system.
In other words, Australia has so many good sites for PHES that only the best 0.1% of them will be needed. Developers can afford to be choosy with this significant oversupply of sites.
Pumped hydro sites in Australia. ANU/ARENA, Author provided
Here is a state-by-state breakdown of sites (detailed maps of sites, images and information can be found here):
NSW/ACT: Thousands of sites scattered over the eastern third of the state
Victoria: Thousands of sites scattered over the eastern half of the state
Tasmania: Thousands of sites scattered throughout the state outside national parks
Queensland: Thousands of sites along the Great Dividing Range within 200km of the coast, including hundreds in the vicinity of the many wind and PV farms currently being constructed in the state
South Australia: Moderate number of sites, mostly in the hills east of Port Pirie and Port Augusta
Western Australia: Concentrations of sites in the east Kimberley (around Lake Argyle), the Pilbara and the Southwest; some are near mining sites including Kalgoorlie. Fewer large hills than other states, and so the minimum height difference has been set at 200m rather than 300m.
Northern Territory: Many sites about 300km south-southwest of Darwin; a few sites within 200km of Darwin; many good sites in the vicinity of Alice Springs. Minimum height difference also set at 200m.
The maps below show synthetic Google Earth images for potential upper reservoirs in two site-rich regions (more details on the site search are available here). There are many similarly site-rich regions across Australia. The larger reservoirs shown in each image are of such a scale that only about a dozen of similar size distributed across the populated regions of Australia would be required to stabilise a 100% renewable electricity system.
Araluen Valley near Canberra. At most, one of the sites shown would be developed. ANU/ARENA, Author provided
Townsville, Queensland. At most, one of the sites shown would be developed. ANU/ARENA, Author provided
The chart below shows the largest identified off-river PHES site in each state in terms of energy storage potential. Also shown for comparison are the Tesla battery and the solar thermal systems to be installed in South Australia, and the proposed Snowy 2.0 system.
Largest identified off-river PHES sites in each state, together with other storage systems for comparison. ANU/ARENA, Author provided
The map below shows the location of PHES sites in Queensland together with PV and wind farms currently in an advanced stage of development, as well as the location of the Galilee coal prospect. It is clear that developers of PV and wind farms will be able to find a PHES site close by if needed for grid balancing.
Solar PV (yellow) and wind (green) farms currently in an advanced stage of development in Queensland, together with the Galilee coal prospect (black) and potential PHES sites (blue).ANU/ARENA, Author provided
Annual water requirements of a PHES-supported 100% renewable electricity grid would be less than one-third that of the current fossil fuel system, because wind and PV do not require cooling water. About 3,600ha of PHES reservoir is required to support a 100% renewable electricity grid for Australia, which is 0.0005% of Australia’s land area, and far smaller than the area of existing water storages.
PHES, batteries and demand management are all likely to have prominent roles as the grid transitions to 50-100% renewable energy. Currently, about 3GW per year of wind and PV are being installed. 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.
Fast-track development of a few excellent PHES sites can be completed in 2022 to balance the grid when Liddell and other coal-fired power stations close.
Editor’s Note
Andrew Blakers is Professor of Engineering, Bin Lu is Ph.D. candidate and Matthew Stocks is Research Fellow, all at Australian National University.
For full details on their research, see here.Â
This article was first published on The Conversation and is republished here with permission.
[adrotate banner=”78″]
Bob Wallace says
Great study. Now we need similar studies elsewhere.
We’ve been using pump-up hydro storage (PuHS) for more than 100 years. There’s no doubt it works. And it’s affordable. Around the world we built over 400 PuHS facilities to time-shift nuclear reactor output.
This study looks at constructing both upper and lower reservoirs (for the most part). In the US we already have many places where the upper reservoir is in place.
In 1997 a study of existing dams on federal land was performed. The researchers were interested in seeing if any were potential power producers. They looked at 871 existing dams and screened them for adequate hydraulic head (enough pressure to run a turbine), enough stream inflow, reasonable distance from transmission lines, outside of protected areas, etc. They found that 6 had hydro generation potential. That together they could produce 1,230 MW. Enough power for 957,000 residences
http://www.usbr.gov/power/data/1834/Sec1834_EPA.pdf
Luckily they posted a list of all 871 dams in the appendix, along with dam height/head.
I worked my way through the first 212 of the dams that were ruled out as power producers due to inadequate stream inflow. Out of that 212 sample 29% (61) had at least 50′ of head. 9% (19) had at least 100′ of head. And 4% (8) had at least 190′ of head. 43% of the 212 had PuHS potential.
In the US we’ve got around 80,000 existing dams. We use about 2,500 currently to produce electricity. That leaves us with approximately 77,500 candidate existing dams.
Using the federal dam percentages we might expect 22,475 with greater than 50′ of head. 6,975 with greater than 100′ of head. And 3,100 with greater than 190′ of head.
Potentially thousands of existing dams usable for pump-up storage.
The we have thousands of abandoned rock quarries and open pit mines. And our locations for closed loop PuHS would likely dwarf Australia’s.
A study of Europe’s PuHS potential sites found over 9,000 places where either one or both reservoirs are already in place. For those with only one reservoir there is adequate land within an acceptable distance to create the second reservoir.
There are 340 sites in Germany. over 1,700 in the UK, and even 11 in “flat” Belgium.
http://ec.europa.eu/dgs/jrc/downloads/jrc_20130503_assessment_european_phs_potential.pdf
PuHS may not be our ultimate storage solution but it is our ‘floor’. We know it works. We have more than enough places to install. It’s affordable. If we don’t invent better/cheaper ways to store we, at least, can depend on PuHS to give us the storage we need for a 100% RE grid.
Nigel West says
Re. the USA. Just quoting numbers of potential sites is meaningless, particularly when the vast majority are under 50MW in size so would be too small to be economic. Much more important is being able to assess suitability for pumped storage hydro. For that you would need to have engineering skills to judge:
– is the site capable of >500 MW capacity, otherwise unlikely to be economic to develop?
– location relative transmission connections re. feasibility and cost?
– for existing conventional hydro could a second reservoir be built without affecting river flows and impacting irrigation and water supplies, and with acceptable environmental impact?
– what is the potential storage capacity in GWh?
Typically, a large economic to build PHS project would have a storage capacity of around 10GWh. Annually the US consumes around 4,000,000GWh of electricity. So just to buffer a days worth of electricity, around 10,000GWh, on a 100% RE grid would require around 1000 new large PHS plants. In an electrified all RE scenario electricity consumption would be far higher than 10TWh/day too, and round trip efficiency of 75% would push up storage needs.
A new 10GWh scheme could cost around $3bn. Say $1.5bn to account for existing reservoirs. Even for the US $1.5Trillion would be uneconomic, and doesn’t include transmission costs either.
Anyway, US academics, Clack et al responding to Jacobson’s report, have already looked at this and ruled out PHS being feasible on the scale needed for a 100% RE grid. Similarly, for the UK the former Chief Scientific Advisor Prof. Mackay examined PHS potential and found it not feasible.
Bob Wallace says
(…)
I clearly stated that the thousands of dams that are potential PuHS sites are close to existing transmission lines.
Do you seriously think that out of over 20,000 candidates we could not find adequate capacity?
Hans says
MacKay and Clarke probably did not use the method used by Blaker et al. It would be interesting to have Blaker et al have a go at the US and the UK and see how much previously overlooked potential they can find.
Hans says
Sorry: BlakerS et al.
Bob Wallace says
Someone has already identified major places in the UK where more pump-up storage could be built. I didn’t save the source.
The US has no shortage of sites.
The big question is how much PuHS we would actually need. Will another technology such as power to gas turn out to be less expensive? What will the economic threshold be for simply overbuilding and storage? And to what extent will we find dispatchable loads that we can use to allow us to increase our wind and solar capacity and minimize curtailment?
Recently I was in a discussion about dam sedimentation. A solution for many of the dams that gradually fill with sediment might be autonomous suction dredges. Small to modest sized units that operated only during supply peaks.
They might stay in their ‘boat houses’ seasonally and/or only operate late at night when there is no other demand for the power being produced.
Nigel West says
I think it’s correct to say that to date all the major pumped hydro schemes are based around rivers to fill the reservoirs and provide make-up. That together with the need for adequate head and acceptable environmental impact, means suitable sites are not abundant.
Whereas Blaker’s report suggests potential locations that are dry would be suitable. That would require pumping vast quantities of freshwater via pipelines to fill the reservoirs and make up for evaporation. Availability of freshwater could be an issue, certainly in locations where rainwater is limited.
Locations close to the coast could draw sea water rather than use freshwater resources. A small demo. PHS plant operated on Okinawa. Corrosion and seal technical issues arise using sea water.
Bob Wallace says
No, it does not at all mean that suitable sites are not abundant. It means that the easiest sites get used first.
There’s no practical limit on pump-up hydro storage.
“Whereas Blaker’s report suggests potential locations that are dry would be suitable. That would require pumping vast quantities of freshwater via pipelines to fill the reservoirs and make up for evaporation. ”
There are plans for seven PuHS sites in Utah. They would be filled with a portion of streamflow during the rainy season. It would take about three years to totally fill them based on historic streamflow data. After that they would need an annual top up during the rainy season to replace what is evaporated.
Nigel West says
Utah is the second driest US state and the population is forecast to double by 2050 needing water brought in from far away. So good luck with finding the water for PHS when there are far more pressing demands.
Even if the water were available, three years to fill reservoirs and commission on top of the main construction period would likely make the projects uneconomic to develop.
Many of what you believe are practical locations for PHS will fail to be suitable for technical, environmental or economic reasons when looked at in detail by engineers and investors.
Bob Wallace says
Nigel, I just told you that multiple PuHS sites have been planned out for Utah and told you where the water would come from.
I offered that information specifically to show that even in places where one might suspect PuHS would not work reality says elsewise.
Three years to fill simply means that for the first two years the site would be able to store for fewer days in a row than once totally filled. Starting the first year the site would be able to do solar to night type storage with no problems.