Re: Nuclear Power, Do you support it?
Continued...
Apart from Tasmania where it would add energy to an energy-constrained hydro system (thus being a legitimate alternative to building new power stations of any type), wind is not an alternative to building new power stations for the other states.
Much is often said about air-conditioners adding to power demand. Whilst they do add greatly to peak power demand (especially in Vic and SA) they use relatively little energy overall. So they cause more power stations to be built but don't add hugely to fuel use or emissions. Indeed there are several power stations (particularly in Vic and SA) which rarely run for this reason - they generate large amounts of power infrequently and thus use little fuel overall despite burning it at a high rate when operating. Dry creek, Quarantine, Hallet (all in SA), Somerton (Vic) and Jeeralang (Vic) are all examples of such plants.
Despite being connected to Victoria via two separate interconnectors (interstate transmission lines), the SA grid is too small to support any single power generation unit on the scale of an economic nuclear power plant. Nuclear generating units are large for economic reasons. The large power plants in SA (Torrens Island is the only "large" plant in SA) use multiple smaller (200 MW and 120 MW at Torrens Island) generating units for this reason. The underlying problem is simply what happens when the machine unexpectedly goes offline (this happens quite often with all types of power generation). Take 800 MW out of the SA, WA or Tas grids and the whole lot will go down with it. NT doesn't have a much of a grid to start with.
Imports to Tas via Basslink (the Tas - Vic interconnector) are typically limited to 250 - 380 MW for this reason (the link can carry 480 MW continuously or 600 MW at peak). If it tripped offline from, say, 500 MW in the middle of the night then that would take the rest of the Tas grid down with it - a complete statewide blackout which would take some hours to restore. Given that this could happen quite often, it's not an option. Indeed even having a single 350 MW source (the largest generating unit in Tas apart from Basslink is 144 MW (3 units each of that size in the one power station for this very reason of system stability if it fails)) is only possible with a rather complex system which automatically cuts power to some very large customers (mostly smelters and paper mills) if Basslink shuts down unexpectedly.
It's worth noting that wind turbines lack the physical inertia of conventional generating plant and will thus tend to trip offline if anything goes wrong in the power system. For that reason having 50% wind in the grid isn't really an option either. One transmission line fails and that causes half the generation to shut down thus overloading the remaining generation causing that too to shut down - the whole grid goes down.
It would, however, be possible to generate large amounts of electricity in SA for export to Vic if smaller generating units were used. So this problem doesn't preclude the development of a large geothermal industry there provided that it consists of multiple smaller turbines and not one large one as a nuclear plant would.
So the debate about nuclear power is necessarily one about building a nuclear power staton in Qld, NSW or Vic. Since Queensland has an existing abundance of power generation and more already under construction and also has the cheapest coal costs, that isn't the logical place for a new nuclear power station.
That leaves NSW and Vic, both of which are relatively short on electricity and are needing new capacity.
The much maligned Victorian brown coal is actually very clean in a chemical sense. The problem is that due to high water content (up to 70% in operating mines) a lot of energy is used driving off that water at the power stations (hence the large steam plumes from the stacks at Loy Yang and Yallourn in particular). This causes more coal to be used per unit of electricity than the higher grade (low water content) black coal used in Qld and NSW (lower grade black coal is used in SA and WA) and hence higher greenhouse gas emissions.
But the good news on brown coal is that, apart from carbon dioxide and water, it doesn't emit too much else. It's chemically "clean" despite being inefficient and a big source of carbon dioxide (about 20% more than black coal).
Given the close proximity of the Bass Strait oil and gas fields and their depletion (the oil is over 90% gone) this makes Victoria the most logical place if there is to be capture and storage of carbon dioxide emissions from power stations. It's still not a cheap or easy process, but it should be easier in Vic than elsewhere.
In the meantime, there is also the possibility of converting brown coal to diesel fuel. Given the oil situation this would make considerable sense both physically (secure supply) and economically. The wastes from that process are then burnt to generate electricity more cleanly (in terms of greenhouse gas emissions) than conventional brown coal power generation. There has already been one proposal to do just that.
NSW on the other hand has lesser prospects for storing carbon dioxide underground and higher coal costs than Qld. And it needs new generating capacity but doesn't have the brown coal useful for making diesel. Nor does it have large scale access to natural gas for peaking power plants. However, there is a lot of potential to add peaking hydro capacity in NSW via modification of the Snowy scheme or building new hydro capacity. Whilst this wouldn't add energy to the system, it would add peak power. Existing NSW coal-fired plants have substantial unused energy capability but insufficient peak generating capacity. So run them harder and push the existing hydro output more towards the peaks. This would, however, do nothing to reduce greenhouse gas emissions.
Solar thermal power stations can generate power 24 hours per day. Basically it's a large greenhouse (literally) producing hot air which rushes up a "chimney" at very high speed to drive turbines located at the base. Like a hydro-electric scheme but in reverse (air rising instead of water falling) and using hot air rather than water. Not a total solution but estimates suggest that it ought to be reasonably cheap (comparable to coal or at least gas).
As for biomass, that's simply burning wood etc in a conventional power station rather than coal (though it's typically done at separate plants built near the wood to minimise transport).
Conclusions...
Geothermal seems likely to have real potential for development in SA. Given SA's high electricity prices (due to substantial reliance on gas) the economics aren't that bad. And it's virtually zero emissions and should be cheaper than nuclear. Geothermal also holds considerable potential in WA, Qld and NSW although SA is the leader.
Hydro can add modestly to total energy production (new dams) but can add greatly to peak power production. Doing this delays the need for new fossil fuel or nuclear power stations and is mostly of relevance to the eastern states.
Wind isn't overly cheap but as a means of reducing greenhouse gas emissions it would make sense to build more wind power in Tasmania rather than Tas relying more on mainland coal-fired power as would otherwise be the case.
High-tech brown coal power stations could both help solve the liquid fuels problem and also supply huge amounts of electricity in Victoria. Again, the process is reasonably economic especially when compared with nuclear.
Solar towers are somewhat unproven on a large scale but in theory at least it's reasonably economic. Certainly cheaper than nuclear as a means of reducing emissions and it does add some firm power capacity (unlike wind). There are good sites convenient to the NSW grid.
So overall I think the way ahead is to push ahead as fast as possible with geothermal since that is the big hope for cheap, clean electricity in this country. It would also end SA's problematic high dependence on natural gas.
Elsewhere, solar towers seem to have a contribution to make in NSW especially as does wind in Tasmania. Biomass has a limited role to play in various locations.
With new brown coal plants in Victoria (cleaner than existing plants plus the diesel production) there is another large source of electricity. It is also possible to build considerably cleaner coal-fired plants (about one third lower emissions) without the diesel production. And of course geosequestration is another option (put the carbon dioxide into old gas fields).
A reworking of hydro power more towards peak production would add to the viability of any new approach to power generation, nuclear included, and thus makes a lot of sense. Greens will fight to the end to stop it though since opposing hydro is to the greens what industrial relations is to Labor.
Nuclear? We may have to eventually but the alternatives haven't been properly investigated yet. It would make economic and environmental sense ONLY if geothermal, solar towers and geosequestration are not viable. Given the projected economics of geothermal and solar towers they are quite likely to be a cheaper option. At the very least we should build a medium size geothermal and solar tower plant to assess the costs before comitting to what is certain to be an expensive nuclear power plant.
For the nuclear industry there is thus a degree of urgency - build it now before geothermal, solar towers of carbon capture becomes a cheaper option. Given that greenhouse is a long term problem rather than a short term one, waiting another 5 years to assess the viability of these alternatives would be a low risk strategy.