Image for A Pumped-hydro Bonanza for Tasmania ... ?

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Pic: Lake Gordon, Mt Wedge in the background. Daniel Patman, Flickr

First published September 9

Most of it won’t happen. Here’s why …

It’s a state election year, and what better than to announce a brave new, multi billion pumped-hydro phantasmagorical bonanza for the state. Fifteen dams, two new Basslinks, Tasmania the national hero. The sort of grand vision that can get governments elected.

Meanwhile, our Prime Minister is being dogged left, right and centre by a hopelessly failing national energy market and is throwing money around like nobody’s business to look like he is on top of it all.

Put those two political ingredients together and then read between the lines in media those ebullient headlines about how plucky little Tasmania is going to save the nation. We won’t do that. We can’t do it. But we do stand to gain a few million in feasibility studies and that is what this is mostly about.

First up, let’s inject a little bit of essential education:

•  Pumped-hydro should not be classed as renewable energy. It is a means of storing energy that has been generated elsewhere and then releasing it at peak times. It is plainly disingenuous to label that energy as ‘renewable’.

• Used in this way, pumped-hydro can help to to iron out peaks and troughs in the energy market. But it’s not the only way, nor necessarily a cheap way of doing so.

• Though pumped-hydro can be utilized, theoretically, to help buffer intermittent wind and solar energy, by far it’s biggest benefit is for the coal industry. Why?  Because coal-fired generators are hopeless at rapidly matching their power output to fluctuating demand.

• The economics of running coal-fired power stations pivots around stabilizing their output. What’s more, if Australia has are fewer coal-fired stations (because older ones are being closed down) then the remaining ones will have increasing trouble meeting the nation’s peak load.

• The most cost efficient way to keep the furnaces stoked through the night is to choof out more power than is actually needed at that time, and store that energy for peak hours when the system is under stress.

• Enter pumped-hydro. Go back up to the first dot point above.

• Now … for Tasmania to provide this national service we have to look at a few basic sums. And this is essentially why the sums for Matt Groom’s sales pitch won’t add up.

• Generate electricity on the mainland (from any means) and post it to Tasmania and these are the real power losses that occur:

– Transmission across Basslink = 10% energy loss.

– Pumping losses – due to frictional flow = 20% energy loss.

¬– Transmission back across Bass Strait = 10% energy loss.

• Add these up and we have a net energy loss of 40% - conservatively estimated.

• Then look at the multi-billion cost of building all of that infrastructure. Approximately $1 billion apiece for each new Basslink. Several hundred million for each or those buffer dams and pumping stations.  To be competitive these investments would have to compete against other alternative ways of stabilizing the national grid.

•  At this point we need to look at what is really going to happen in the next ten years or so – i.e. the period in which all that Tasmanian infrastructure would be built. The rest of the country won’t be asleep at the wheel. Investment decisions are being made now.

• On-site gas-fired generators (they have rapid fire-up ability and therefore can meet peak load quite readily) are being installed as we speak. Pumped-hydro facilities will be built in a few sites along the eastern ranges. A world first battery storage bank is being installed in South Australia. Other promising storage technologies are being talked up.

• The important thing about all of these possibilities is that these will mostly beat the pants off anything that we can do remotely, and in many cases much more quickly. As what happened with the building of Basslink 1 the business case would most likely disintegrate long before the on-switch can be pressed.

• Now let’s go back to the first dot point again. Tasmania has no net surplus hydro power to sell.  Say that again. Tasmania has no surplus power to sell. The existing hydro-wind system supplies approximately 90% of our power demand. The rest has to be supplied from Tamar Valley gas station or by importing power across Bass Strait.

• Which is what we are doing right now. The Tamar Valley power station was hammering out about 200 MW continuously throughout the first 6 months of this year and, with dam levels at 40 percent in early Spring, it was fired up again last week.

• To make along story short, it would take a lot of effort and investment just to get Tasmania to 100 percent self sufficiency in its power output. Yes, we should aspire to doing that.

• The phantasmagorical scheme being proposed for Tasmania talks up extra generators being installed and so forth, but the fact remains that we only get so much rain. By way of example, the proposal to add an additional generator at Gordon power station will not produce one kilowatt more power. It would enable Hydro Tasmania to drain Lake Gordon more quickly, and then to restore that volume by importing power.

• The scheme may, here and there, enhance the performance of the existing hydro system by hotting it up a little, but this is not the mainstay behind the grand proposal.

• OK, what then about the need for storage for wind and solar energy? Isn’t that a justification? Yes, but here we need to look at the ability of our very able hydro-electric network of dams to do that right now. No investment needed.

• Thanks to climate change, Tasmania is suffering dwindling water run-off into Hydro Tasmania’s impoundments. This means that these days our dams are rarely full. Mostly below 50 percent full.  The plus side is that is unused storage capacity can be used to store energy, immediately, from any other source.

• For most people this needs a little explanation. How can you turn electricity into water?... is what goes through their heads.

• This is how it works. Any additional power that is fed into the Tasmanian grid means that less hydro power needs to be generated. Thus the turbines are throttled back and that amount of water is allowed to build up in the dams for later use. The point is, that there is ample capacity to absorb almost any amount (at least 500MW) of non-hydro renewables into the system right now. Until such time as this unused system capacity is utilised this is where our cost competitive opportunity lies.

• Ok then: why can Tasmania not be a massive storage for mainland wind and solar power in the future? That’s answered further above. It would have to provide a cheaper buffer than can be done by other means on the Mainland and without the immense energy losses. It would be folly to produce power from solar panels in Queensland, shunt it to Tasmania for temporary storage and then shunt it back again. We don’t need to be rocket scientists to grasp those sums.

• I deliberately haven’t mentioned here the physical imposts of the grand pumped-hydro scheme on Tasmania, the wilderness state. There would be huge implications for downstream river ecologies consequent running our rivers madly for short bursts, let alone the building of all those 15 buffer dams downstream of existing dams. But let’s put this aside for now partly because these environmental concerns issues are of little interest to most decision makers. More so, the scheme is so hair brained most of it will never happen.

• So what’s this pumped-hydro bonanza for Tasmania really all about then? It’s about exploiting the political moment to the financial advantage of the state government and to the political advantage of the Turnbull government. Let’s make no mistake, this calculated sales pitch could pragamatically deliver to Tasmania a decent package of money just to look into it and dabble around with some bulldozer work. If the vision - improbable as it is - serves to get the state government re-elected then it will have served its main political purpose.

• I must add here that some augmentation of Tasmania’s power system is definitely in order. The main impact we are suffering from as a result of Basslink being installed is a lessening of energy security. This is because successive state governments have found it cheaper and more convenient to allow the importing of off-peak coal power than to facilitate extra on-island wind farms. 

• Using our existing system capacity and potential is where our primary policy focus should be. This is where we can sanely facilitate additions of renewable energy generation, and on a cost effective basis.

*Chris Harries is an environmental educator specialising in energy supply & demand issues. He is a member of the Climate Tasmania advisory body and has played a major role in the uptake of domestic rooftop solar in Tasmanian communities. He has been writing on environmental and social advocacy issues since the mid 1970s.

• Gordon Bradbury in Comments: That’s not Spring in the air. That’s the smell of testosterone and election fever. Bring on the parades. Bring on the dancing girls and marching bands! Bring on the promises of money and jobs, money and jobs, money and jobs!!! And don’t forget the “Grand Visions”. Especially for Tasmania. Tasmania is the home of “Grand Visions” …