Thursday, December 13, 2007

Greenhouse gas - reduce how exactly?

Over at Slate, there's an interesting article talking about just how "green" are fully electric cars in reality. (Answer: pretty damn green, especially if you live where nuclear power makes your electricity.)

The article made the point that in the US, 49.7% of all electricity is coal generated.

This got me thinking about the Australian situation, and what it means for the range of CO2 reduction which the post-Kyoto Bali conference is talking about.

According to a paper by the WWF (downloadable here,) coal accounts for about 85% of Australian electricity, hydro power is about 8 % (more than I thought) and natural gas is 7%. This Parliamentary Paper from 2000 indicates that the figures are about right: there might be one or two percent of wind, solar and other renewables as this pie chart from the paper (showing the renewable energy components in Australia) indicates:

but really, hydro power is the only truly significant "green" electricity we have at the moment.

As everyone has probably heard, the Bali conference is talking about total emissions reductions of 25 to 40 per cent by 2020. Kevin Rudd is (so far) insisting that he won't be nominating Australia's target just yet. But, even assuming a 30% target is what Rudd settles on, what does this mean for our electricity industry?

According to this recent government paper, close enough to 50% of Australian greenhouse gases come from electricity generation. Transport accounts for 12.5%, about 23 % comes from agriculture and land use, and industrial and waste seems to account for much of the rest.

The paper confirms too that Australia has kept pretty close to the Kyoto target (which still allowed an increase on 1990 emissions) by reducing land clearing. I would guess that further progress that could be made in reducing land clearing is probably getting limited.

As for transport; it's hard to see how a 30% reduction in that sector is likely to be achieved without massive changes over the next 13 years. Maybe a 10 to15% reduction, but remember that whole sector only accounts for 12.5% of total gases now anyway.

So, it would seem, if Australia is to have any hope at all of meeting a 30% reduction within 13 years, the electricity sector is going to have to bear the greatest burden of this change.

Even if renewables made a massive increase from its current 8-9% (nearly all hydro, remember) to 20% (the target Rudd has already set for 2020), and you give natural gas another percent or two, it would still leave about 70% or so of electricity from coal.

Roughly speaking, (and I won't put my back of the envelope figures up in case I have stuffed this up completely), it seems to me that even if you allow for renewables at 20% of all electricity, you would still have to have about half of your coal as "clean" coal for the energy sector to be able to come close to accounting for the bulk of the total target of a 30% reduction in CO2.

My suspicion, based on European experience (see some of my earlier posts) is that even with massive investment, renewables at 20% is very, very improbable by 2030. I also suspect that having about one half of all coal power stations operating at zero emissions by 2030 is very, very improbable. Quite frankly, no one knows how well CO2 sequestration will work. People do know that nuclear does not make CO2.

My points:

1. Australia's extremely high reliance on coal makes it exceptionally difficult for it to meet a target even towards the lower end of the range that the UN says Australia should have in 13 years from now.

2. Those countries that have or will develop large proportions of nuclear power in their electricity generating mix have a task that is very significantly easier.

3. People in Australia don't understand this yet.

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