Climate Change Energy efficiency

Coal fired power & base-load

Currently, most of our power generation in Australia comes from coal.

One of the problems with coal (and why off-peak power is cheaper than peak power) is that they require a long period of time to heat up to operating temperature and so they cannot be started and stopped quickly.

From the Climate Spectator (Giles Parkinson) comes: “The biggest challenge is how to manage the growth in peak demand, which is growing at a phenomenally faster rate than baseload power. It will come as something of a shock to most consumers that their soaring power bills are not the fault of green energy subsidies, but mostly because of the neighbour’s newly installed air conditioning unit. Or their own.”

Now peak power is generally provided by gas or hydro as they are capable of following demand better but we don’t have a lot of this kind of generation capacity in Australia and it is expensive. Excess coal-fired power that is generated has to be ‘dumped’ – this is done during off-peak times (generally at night). It’s done by various means but one is to heat up pondages of water – it takes a lot of energy to heat water.

We will be moving towards a low/no carbon economy in the near future. One of the technologies that have been touted for producing electricity when the sun doesn’t shine and the wind doesn’t blow is to store the excess solar thermal energy in vats of molten salt. This allows this thermal energy to be recovered later to produce steam to drive turbines.

What if…..

Instead of ‘dumping’ the excess energy generated from coal-fired power stations, we were to store it instead by heating vats of molten salt??

Could this be used as an interim way of producing greater efficiencies from our current generation plants, while we usher in the new age of low/no carbon energy??

Just a thought……

as always, comments are more than welcome.

2 replies on “Coal fired power & base-load”

Dear John,
Thanks for the interesting post. Firstly I’m interested in your comment about rising energy costs and the common perception that this is as a consequence of ‘green energy subsidies’. Do you have more info on the factors which are driving increased energy costs.

As for the idea of storing the surplus heat energy from coal fired power plants has an appealing logic, however, this raises concerns for me. Importantly the financial investment in creating these molten salt storages would create an imperative to continue operating our coal fired power stations, probably longer than we can really afford to do so. Without any realistic proposition to reduce the greenhouse gas emissions from the smoke stacks this would continue to drive our high per capita greenhouse gas emissions. The second is that we fail to recognise that coal is a health hazard and when this is taken into account coal is likely to be one of the most expensive forms of power generation.

For me the focus for a useful discussion should be around strategies to reduce our growing and excessive power consumption. This can be through personal action to introduce energy efficiency measures, industry innovation to provide more efficient products and services and government support in the form of clever urban planning, effective housing standards. In putting all of these together the bonus for people who think with their wallet will be to reduce the daily cost of living while maintaining a comfortable and enjoyable lifestyle.

Thanks for the inspiration and we’re looking forward to seeing you in Tasmania.

Ride on,


Nick, thanks for your comment.
Increased peak energy consumption is the main driver – peak power comes at a cost of tens of dollars per kWh rather than the < $0.05 wholesale baseload costs. If you look at the "windfalls" that PV owners get (~$0.65/kWh) and realise that this energy is generally generated during the peak times of the day, then you see that, rather than making the problem worse, they in fact are of assistance in balancing this peak! This peak load comes from our addiction to high-energy consuming appliances. In our homes it comes from cheap air-conditioners installed and used more than necessary (as building codes mean that developers can get away without putting eaves on houses!); building homes that are the largest per capita in the world (again we have another record with dubious honours attached) - which then require extra heating, cooling & cleaning. In the workplace, our dependence upon ever more powerful computers (that don't get fully powered down at night) when the ones we use currently are generally idle 90%+ of the time. In shopping, large centres that are air-conditioned to 19 degrees C (and then they leave the doors open!). As far as your concerns are concerned; I appreciate what you say and only suggest this as an interim knowing that these energy stores can be used to store excess energy from wind and solar thermal when the coal-fired stations get shut down, as they indeed will be. I proposed this as a way of lessening the carbon impost from these facilities during the interim.
In a previous post I too raised your concerns about the health costs of coal-fired power.
…and I TOTALLY agree with your final paragraph as I too see this as the way forward.
Thanks again for your well considered response.

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