Hydro against batteries: Tasmania pushes its submarine cable plan

There is no doubt that hydroelectric power is a wonderful thing. It’s green, it’s renewable, it’s emissions-free and it’s relatively inexpensive. There is also no doubt that water can be stored behind a dam for days, weeks, months, even years before it is used to turn turbines that generate electricity.

Tasmania has an abundance of hydroelectric power – little more than it needs, in fact. She would very much like to sell some of her excess electricity to the rest of Australia. The plan proposed by Hydro Tasmania and TasNetworks is known as Marinus Link, a 500-kilometer-long submarine transmission line from Tasmania to Melbourne. From there it would connect to the mainland’s power grid, making Tasmania Australia’s National Battery, so to speak.

But there is a flaw in the Hydro Tasmania plan. According to a report written by the esteemed Dr Bruce Mountain for the Victoria Energy Policy Center, the Marinus Link is a losing proposition that will only make less economic sense in the years to come, as the cost of battery storage to the network scale continues to decline. . Here is a quote from the summary that pretty much says it all.

“The main conclusions of this report are that 1,500 MW of four hours battery can be supplied for less than half the cost of Marinus Link; that the same capacity six-hour battery can be supplied for 79% of the cost of Marinus Link and 1,500 The eight-hour MW of battery storage is still cheaper than Marinus Link.

“In other words, although Hydro Tasmania is able to provide, at no additional cost, 1,500 MW that she could export to Victoria day after day for eight hours at a time for the foreseeable future, it will always be cheaper to build 1,500 MW of batteries in Victoria instead. than building Marinus Link. Of course, the Tasmanian power system is far from the power or energy capacity required to provide 1,500 MW of supply to Victoria for 8 hours a day and as many billions will be needed to expand its storage and energy production in Tasmania in order to be able to supply the capacity that Marinus Link claims to offer.

The end of the report is just as brutal. “We now feel in a position to conclude that not only does Marinus Link have no chance of competing with alternative batteries, but that if Hydro Tasmania develops pumped hydro capacity in Tasmania, it is very likely that, like Snowy 2.0, it will be blocked from the start. “

Cuanto Cuesta?

So how much would the Marinus Link cost? The proposal calls for the construction of two new 750 megawatt submarine power cables between Tasmania and Victoria at a cost of approximately $ 3.5 billion. Hydro Tasmania, which is owned by the state of Tasmania, plans to store electricity in dams in Tasmania by releasing water to generate electricity for export to Victoria when prices are high, and by pumping the water in dams when electricity prices are low.

According to MSNMountain says if the Marinus Link is funded by the Tasmanian or Commonwealth governments, taxpayers will have to pay for an asset that would cost more to build than it can earn. “It would be a dead weight on the shoulders of the people of Tasmania, if indeed the people of Tasmania bear most of the cost. If this is borne by the Commonwealth in one way or another, it will place a burden on all taxpayers and energy consumers depending on the end of the supply, when you are building an asset that cannot compete. .

Mountain also expressed skepticism about the long-term benefits of construction jobs associated with the projects. “It would be much better for the community if the government just gave this money – frankly, it would be less of a loss for the community. Building a white elephant, a dead weight loss, reinforces the disadvantage. No namby-pamby, bland words from esteemed Dr. Mountain. Better take that money and throw it in the street.

The case of Marinus Link

Hydro Tasmania and TasNetworks are not giving up the fight. TasNetworks Managing Director for Marinus Link, Bess Clark, said batteries and pumped hydraulic storage will be needed as Australia’s energy market moves away from fossil fuels. “Marinus Link offers a unique opportunity to double Tasmania’s clean energy, help fight climate change, put downward pressure on electricity prices and create thousands of local jobs,” says she, before adding that the modeling of the Australian Energy Market Operator shows the Marinus Link will be a key part of the Australian energy network in the future.

A spokesperson for Hydro Tasmania said the batteries would not be able to meet all of Australia’s energy storage requirements and deep storage like pumped hydropower would be needed. “It’s not about having one or the other. We will need all the relevant and competitive technologies to play their part and ensure that all Australians have a reliable, safe and affordable electricity system, ”he said.

Last week, the Tasmanian Chamber of Commerce and Industry gave its “full support” to the Marinus Link project. “We know this project will be fantastic not only for jobs statewide over the next 50 years, but also for business growth in Tasmania,” said Michael Bailey, CEO of TCCI.

All the foregoing

There are two sides to this debate and they both have points in their favor. Pumped hydropower can deliver electricity much longer than any existing grid storage battery. A battery can respond in milliseconds; pumped hydropower cannot. One of the advantages of battery storage is its ability to regulate frequency and voltage. Both save grid operators money, but these are services hydropower cannot provide.

Then there is the question of timing. Bruce Mountain tells the Sydney Morning Herald the Victorian Big Battery, made up of dozens of Tesla Megapacks, will be commissioned shortly, while a Jeeralan-like installation is expected to be ready by 2026. Four other storage battery projects are also underway. Four other main batteries are expected to continue. These will all be in place and operational before the Marinus link becomes operational.

“Battery storage capacity will be built and operational in Victoria long before the Marinus Link and Battery of the Nation developments in Tasmania are nearly operational,” the VEPC report said. “Marinus Link still has no prospect of competing with the alternative batteries in Victoria. “Mountain adds:”.

“It’s not about having one or the other,” retorts Hydro Tasmania. “We will need all the relevant and competitive technologies to play their part in ensuring that all Australians have a reliable, secure and affordable power system.” Tasmania is also investing heavily in wind power, which it also has in abundance.

The problem with the transmission

Solar energy advocates like to say that a gigantic solar farm in a small corner of the Sahara Desert could power all of Europe and the UK – if there were transmission lines connecting the two areas. In the United States, some dream of New Yorkers getting solar power from California after the sunset over the Big Apple. This could happen if there were high voltage transcontinental transmission lines.

That being said, transmission lines can be extremely expensive to build and maintain. They are also prone to disturbance from a number of causes – wind, earthquakes, forest fires, even malicious damage. The world learns a hard lesson about making things in one place for consumption in another place by using a flotilla of freighters to connect the two. Anything that can go wrong often goes wrong and at the worst possible time. Just ask Puerto Rico to rely on remote power plants to power its major cities.

Pumped hydropower is an important piece of the energy storage puzzle, but it cannot simply be installed near places where the demand for electric power is high. In theory, battery storage facilities can be located almost anywhere. Ideally, they can go where there are disused thermal power plants, places with the advantage of already having the connections necessary to supply the electrical grid with stored energy.

It’s hard to plan for the future

The objection is not to Tasmania’s abundant hydropower. The objection is the cost of transportation to distant markets at a competitive cost. Then there is a time for considerations. What may seem like a good idea today may not look as appealing in a few years, when the economy leans more in favor of one solution than another. When there is not an unlimited amount of money, it is best to invest what you have in solutions that will be fiscally viable for the longest period of time, not ones that will become economically uncompetitive before the end. of its useful life.

Perhaps Tasmania would be wise to invest its dollars in technologies that turn its excess electricity into green hydrogen or ammonia, which could then be exported at a reasonable cost to anywhere in the world. The problem is not the storage of energy. The problem is the transmission of energy. It will be interesting to see how this plays out in Australia, where sound energy planning at the federal level seems to be an alien concept.

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