That renewable target

This is another post where I try to get my head around energy issues from some Web sources. Anyone who has more accurate figures readily at hand is welcome to correct me.

I just saw some of Skynews Eco Report, in which the Rudd government's 2020 target of 20% energy from renewable sources was being discussed. (Can't find it on the Web yet.)

I think the female guest said that by 2010, Australia will have 2% of its electricity generated from renewables, and the 20% target by 2020 is made even worse by expected growth in demand for electricity (via population growth, presumably) in the same period.

However, this 2 % figure isn't right (or maybe I misheard her); a parliamentary paper from 2000, which I have referred to before, said we were already at something like 10% for electricity from renewables, but it was supposed to increase (by mandated government target) by 2% by 2010. Maybe that is the source of the 2% figure?

This 2004 fact sheet, from the Renewable Energy Generators Association, gives a better idea of the problem. It appears that, as of 2004, it didn't look likely that the mandated increase would be met. The problem has been that, after the enormous boost the Snowy Hydro scheme gave to renewable energy, the total proportion of renewable energy for the nation subsequently went into a pretty steady decline, as growth in demand was met by fossil fuels.

If I can follow the second table on that fact sheet correctly, it seems to be saying that:

a. total 1997 renewables was 16,000 GWh;

b. even to keep at 10.5% of total electricity by 2010, it would require an additional 9,500 Gwh from renewables;

c. to get to 12.5% by 2020 would take an additional 21,000 GWh;

d. to get to Labor's 20% target will take close to 45,000 GWh.

But: that government paper I linked to above said that close to 90% of the renewable electricity in 2000 was from hydro electric; a source which is presumably incapable of any significant further growth.

Actually, looking at the government's 2004 MRET (Mandated Renewable Energy Target) Review, it seems that they are now counting solar hot water as a renewable energy source, and in a table in that paper, they have hydroelectric down to 36% of renewables, and "deemed solar hot water" at 26%. (That figure for solar hot water seems kind of high, and almost a bit of a fudge to me.)

The MRET report does seem to confirm that an extra 20,000 GWh is needed by 2020 just to get to 12.5% renewables target. I assume that the REGA paper is therefore correct in its figure of 45,000 GWh to get to 20%.

The issue of how to treat hot water systems confuses the issue. If it were not for them, I would have said the following seems to be the case: we currently seem to get only about 2,000 KWh from renewables other than hydroelectric (that's 10% of 16,000 GWh, plus some extra to allow for changes since the 2000 paper). To get to 20% renewables by 2020 (an additional 45,000 GWh,) would therefore require the amount of current non-hydroelectric renewable electricity to be increased by a factor of (roughly) 23!

So, whatever windfarms, solar and other (non hydroelectric) electricity we have now, it has to increase about 23 times in 12 years.

(As I say, maybe intensive increase in solar hot water changes the figures somewhat, but as that seems not to be discussed much as a strategy, I am guessing that it won't be what rescues us.)

No wonder there is scepticism as to the target, and the Liberals are starting to argue that it will divert resources from the more important task of developing clean coal, which is actually much more important on a global scale. Greg Hunt may well have a good point here.

Anyway, it still seems pretty clear to me that the general public has no idea of the scale of the problem.