Queensland needs around 15 gigawatts (GW) of wind and about 8GW of utility solar plus rooftop solar to go 100% renewable and be self sufficient.
Queensland has around 39GW of wind resource and about 45GW of solar resources. Both the quality and the quantity resource are in the north of the State with “North Queensland Renewable Hub” having enough resource by itself to run the State. The resource in the South of the State is not enough to provide a high level of renewable power to Queensland.
Before the last election the Queensland Governmentt had a “Powering North Queensland” plan, but nothing much has come of it.
The Australian Energy Market Operator, in developing the Integrated System Plan, did not see the need for the North Queensland resource despite the fact that not only is it generally of higher quality but also the wind is negatively correlated with wind in other States.
A high voltage DC transmission link from the North Queensland hub to say Brisbane, about 1700 km away, could be costed at roughly $1.9 billion per GW. There does not appear to be much economy of scale in this.
By contrast, upgrading the existing AC system for one extra GB would cost about $1.3 billion, cheaper but more limited in scope and involving significantly higher transmission losses and losing the ability to provide services like reactive power and black start that AC cannot provide.
Our unsurprising conclusion is that Queensland has something to gain by developing its North Queensland renewable resource. The reality of this would be mightily enhanced with a DC transmission link. Still, the transmission is not cheap and would certainly require good levels of capacity utilization to provide value.
It’s been three years since Labor won the last Queensland Election.
As one of several commitments made in 2017, the then QLD Govt announced the “Powering North Queensland” project. A document outlining the program is still on the internet at: Powering Nth QLD plan
The essence of the plan was providing $386 million to facilitate $1.6 billion of infrastructure spending and create 1400 jobs
The Powering North Queensland plan was to develop a study of more hydro in the Burdekin and to me more importantly “develop strategic transmission infrastructure” in North and North west Qld. As far as the Burdekin Dam goes rather than any expansion the Dam is causing angst over who has to pay for safety upgrades.
And far from more transmission what we now have is curtailment due to “system strength” issues. There is no blame to the QLD Govt for the system strength issues but it is possible to note that the cost falls on projects in North Queensland.
Surely, the QLD Govt has some responsibility for alleviating system strength issues and perhaps we can do better than the mid 20th century solution of synchronous condensers – seemingly the only tool in the AEMO box. What about retrofitting more capable inverters? Or have I got, not for the first time, the wrong end of the stick?
As far as I can see the only commitment the QLD Govt has made is a $132 million part payment of the proposed transmission link to Genex’s proposed Kidston project.
Queensland has around 45 GW of Solar and around 39 GW of Wind resource
And or course the quality of the resource in North Queensland is much higher than in the South, particularly for wind.
In fact the Queensland Renewable Hub (at this stage just a name) notionally based around the small town of Forsayth has enough wind resource on its own to provide all the wind power required for a 100% renewable Queensland future.
Equally, one can’t treat the ISP as the last word on the matter but its indicative.
North Queensland Hub could run Queensland all by itself
However, AEMO did identify a fantastic resource, enough to power all Qld with appropriate firming capability.
The one zone, the North Queensland Hub has 18,600 MW of wind resource. Think about it.
Even allowing for demand growth 18 GW of wind and 8 GW of solar from that one zone together with behind the meter is enough to run QLD 95% carbon free electricity.
It’s true that generally speaking for many varieties of energy problems of one sort or another mean that only a fraction of the resource can be converted to “reserves”, but even so.
By contrast Southern Queensland has less resource, and of lower quality but of course its much closer to the market.
So why didn’t the ISP give more attention to North Queensland?
In a phrase it’s “the tyranny of distance” the North Queesnland Energy Hub is about 1700 km from the Southern Queensland Load. As with everywhere else the existing transmission is “ s t re t ch e d” and cannot support much more generation.
The ISP’s evaluation matrix effectively doesn’t see North Queensland as a significant component of the lowest cost development of Australia’s VRE. Any development is pushed back to the medium/long term .
The ISP low cost solution apparently involves developing lower quality resource closer to load rather than higher quality resource further away.
Yet this stands in contrast to other models that find that both the Tasmanian hydro resource and the Norther Queensland wind resource are keys to a low cost solution.
The ISP proposes about $1.2 bn of augmentation in total most of it not even required until the mid 2030s and basically all you get for that is another 1000 MW.
This works to $1.3m a MW to get the extra generation along the line to the load in the South of Queensland.
But is this a case of missing the forest for the trees?
If the North Queensland Energy Hub is such a great resource why not build a big DC link and have done with it?
A DC cable from North Queensland Hub to say Brisbane is about $1.9 bn per GW
It’s about 1700 KM from Forsayth (a small town roughly in the North Queensland Hub) to Brisbane. That’s roughly the same distance as the proposed Energyconnect.
A desktop analysis by Professor Simon Bartlett ended up with a cost of $1.9bn for a 1000MW DC link from South Australia to Queensland.
Much greater scale has recently become possible. The highest capacity DC transmission system in the world is the 1.1 million volt, 3,300 km Xingjiang to Anhui link with a capacity of 12 GW at a cost of US$5.5 bn.
In addition developments of DC transmission using VSC allows active and reactive power control, ride through capability and, at a cost, input converter stations can be allowed along the route (so that wind and solar can connect at specified points). Using VSC DC line losses about 1.8% per station or for a two station system 3.6%.
By comparison, and its only an indirect comparison Kidston solar farm has an MLF of 84%, Mt Emerald wind 94%, Ross River solar farm 87%.
For our purposes the suggestion is the transmission cost of building out VRE on the North Queensland Energy Hub is going to be around A$1.9m/MW and that compares to the augmentation of the existing AC line at $1.2bn (see fig 6).
In theory, the line can operate at very high capacity utilization and if there was dispatchable capacity in the zone the overall of the efficiency of the system would be high. But in fact despite 250 MW of potential pumped hydro at Kidston there is basically only a limited amount of dispatchable resource in the area.
Of course battery capacity can be added anywhere but what is the point?
Batteries can be added right next to the load. Other possibilities include thermal storage powered by VRE rather than concentrating solar but this remains in the demonstration stage.
In North Queensland total electricity energy demand has shown a small decline over the past 9 years..
Ex Boyne Island, total peak demand is just 2000 MW and arguably plenty of capacity.
The fact remains that the value of developing renewable generation in North Queensland is mostly related to sending the power and energy South.
One potential genuine source of demand is about 250 MW of power at Mt Isa that potentially could be connected to the main Qld transmission infrastructure if the proposed $1.5bn Copperstring 2 link from Townsville to Mt Isa was built.
However, if there was a plan to develop the North Queensland Hub some of the generation around Forsayth would be well place to supply. Equally the Mt Isa “Diamantina” gas plant could provide firming power to the VRE in the region both for local use and running down the DC cable to Brisbane
David Leitch is a regular contributor to Renew Economy. He is principal at ITK, specialising in analysis of electricity, gas and decarbonisation drawn from 33 years experience in stockbroking research & analysis for UBS, JPMorgan and predecessor firms.