Clean coal

The Energy Minister Josh Frydenberg has announced legislation to allow the Clean Energy Finance Corporation to fund coal-fired power stations using Carbon Capture and Storage (CCS), often called “clean coal”. Although there has been plenty of criticism, this is actually a Good Thing.

If it worked at low cost, CCS would solve a lot of problems, particularly for Australia. We could burn coal, and store the resulting carbon dioxide underground, fixing much of the climate change problem without changing anything else. The ease of this (hypothetical) solution is why CCS plays a big role in lots of climate change scenarios.

Unfortunately, cost-effective CCS doesn’t exist, and isn’t likely to. So, barring some great new discovery, the change in CEFC rules is purely symbolic.

What makes the announcement a Good Thing is that avoids the “bait and switch” used by Frydenberg and others in the past, where clean coal is described in terms of CCS, then shifted to included “High Efficiency, Low Emissions” (HELE) coal plants. This term refers to the fact that plants constructed today are indeed more efficient, and therefore have lower emissions per unit of electricity, than those built thirty years ago. But they are still far worse than gas-fired plants let alone renewables or (if it could be made to work) CCS.

37 thoughts on “Clean coal

  1. OT I guess.

    Trump has handed world leadership to China on a platter. This is not a good thing for those who have hitched their fate to the American wagon. If Trumpism is followed for any significant period, the USA’s relative decline will be accelerated.

  2. @Ikonoclast
    On a slightly more positive note, Jeremy Corbyn’s Labour looks to be giving the Tories a run for their money in the UK election, contrary to mainstream expectations. Who knows – he might even win it.

  3. @may
    Western Australia is odd in that they normally don’t allow households and business to export limit their rooftop solar systems to increase the amount of solar electricity they generate for their own use while limiting the amount supplied to the grid.

    Export limiting is not a good thing because it can and does result in clean solar electricity going to waste at times, but it is far better than not allowing rooftop solar at all.

  4. I say, stop using the term ‘clean coal’ and use the correct term ‘dirty coal’.

  5. @may

    The issue with much of remote Western Australia is that they have town-size micro grids and big diesel generators to power them. They’re in the gap between modern microgrids and proper grids. Even the Perth “grid” is at the “very small grid” end of the scale.

    That makes them vulnerable to instability and especially to over-supply. In the middle of a sunny day if the solar PV systems are producing more power than the town needs there’s no provision for dumping that power or turning off just a few of the PV inverters. So voltage goes up and everything cuts out.

    What they need is a “smart grid” that can link a bunch of the PV systems to the grid control. That would make the whole system more stable. But it would be a new and untested experiment, so it’s unlikely that WA will do it. Or any Australian government, for that matter.

    They other problem they have is that the state government subsidise the system, so it can’t be profitable and thus investment in it can (almost) never pay off. To make it profitable they’d have to replace the existing generators at a supply price of about 20c/kWh. That’s hard.

  6. @Moz of Yarramulla
    They need ways to power the fossil fuel parts down during the middle of sunny days, not power down the solar.

    The opportunity that low cost solar provides for spurring change in electricity generation systems should be maximised, not minimised, with fossil fuel plant having to face running intermittently, only when needed as a step along the way; the increased costs outside those sunny periods that intermittency burdens them with should be seen as the de-facto carbon price governments are too short sighted to introduce and used to spur commitment to storage, demand management and efficiency.

  7. @Ken Fabian

    Ken, the big problem is when they need the fossil plants to draw energy from the grid rather than supplying it.

    The small problem is that home-scale solar inverters are not designed to produce a stable grid, they’re designed to be stabilised by the grid. That means that the grid must always have a certain proportion of supply coming from the generators or it will go unstable – most likely just frequency, but it could easily turn into voltage spikes as equipment fails.

    The solution of “spend money on experimental smart mini-grids” seems unlikely to me. If the mining companies aren’t doing it, expecting a state government to go out on a limb and try it is wishful thinking. I’d love to be wrong, but seriously, experimenting on Karratha? It’s 15 hours drive from Perth, it’s 5 hours flying time from Sydney if you charter a plane, it’s ugly to get a shipping container there from China. Maintenance is going to be expensive. So anything you ship out there should be reliable and well-proven. There’s also no real fall back position – if you blow a transformer or switching gear at the main Karratha substation, no-one gets electricity until you fix it.

    It would make a lot more sense to try this in Canberra or Broken Hill because they’re closer to civilisation and have a real grid to fall back on when things go wrong. Viz, if the mini-grid looks like crashing they can shut it down and switch back to the east coast grid, and that won’t break anything.

  8. I should have thought, Moz, that for the mini-grid (ie between “micro-grid” and “grid”) the issue is storing that peak “too much voltage”. And it’s the one scale where things like molten salt or compressed air storage are viable; below that you’d be thinking batteries, above it you need less storage anyway and what you have would probably be hydro pumped storage.

    But its a small niche globally anyway – I don’t think its going to make much difference to world CO2 emissions if you just stick with diesel or natural gas for baseload for the rare Karrathas of this world.

  9. @derrida derider

    DD, storage is definitely one solution. I suspect the issue is that with unbounded solar take-up they’d have to keep adding storage very quickly to prevent the big problem above. A municipal battery could work, but someone would have to add a million dollars of capital expenditure to a budget somewhere.

    But it really is a political problem as much as anything else. If it was engineering we’d probably see small communities on the fringe of the WA grid being wired up this way, or quite seriously, the ACT. ACT votes green/left quite emphatically and have a known tendency to vote for weird experiments. Saying to an especially green suburb or two “we want to roll out smart inverters, the quid pro quo is that they’re 10kW rather than the 5kW you’re allowed now, and they work with batteries (plus we’ll allow you a feed in tariff with the batteries)”… I think they’d take it up. At least in big enough numbers that you could experiment.

    Once you had that working somewhere accessible you could roll it out to more remote areas and start really hammering the combination of big-residential arrays with batteries and smart internet co-ordination. People are working on this, but at the “scraping up a few hundred thousand dollars here and there” level. Dump a few million onto RedFlow or someone at Sydney Uni and I think it would get very exciting very quickly.

    The really annoying part is that diesel generators are insanely costly to run, so even a cycle cost of 25c/kWh for batteries is doable, as long as you’re not paying for diesel generators to feed them (some remote communities do that to get around generator reliability problems – it’s cheaper to run LEDs off old car batteries than have a second genset).

  10. So anything you ship out there should be reliable and well-proven.

    But this problem was actually solved for regeneratively-braked electric tramways more than a hundred years ago: you need a dummy load, a fuck-off bank of resistors or something. You can make them out of baling wire, even.

  11. Moz, it’s a transition and we are approaching a foreseeable tipping point and it’s a significant one on the path to low emissions. Shoring up the fossil fuel side is a mistake when it’s the right time and place to start incorporating storage into the systems – so the fossil fuel plant can power down more often and shift into the intermittent backup role that is it’s near term destiny. Storage, even at relatively small scale, can help accommodate that shift, including by it’s ability to provide services like frequency and voltage control as well as load levelling; if nothing else it can provide the time for slow responding plant that is not ideal for that purpose to do so.

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