The curious math of Amory Lovins

Do the math: simply repeating 2011’s renewable installations for three additional years, through 2014, would thus displace Germany’s entire pre-Fukushima nuclear output.

Or so claims Amory Lovins in a new piece about renewable energy in Germany. Anyone with even a passing knowledge of the level of nuclear power in Germany will recognise this claim is utter nonsense within about two seconds. However, since Lovins appears incapable or unwilling to do the basic arithmetic, let’s do it here. A couple of minutes on Google can find a summary of German solar and wind installations in 2011:

To make it terse: 7.5 GW of solar and 1.9 GW of wind was installed in 2011. The figures in Lovins piece show that nuclear power generated 130 TWh of juice in 2010, and this is in line with what the IEA says. How would the annual production of 2011’s new renewables installations compare?

7.5 GW of solar in one year (assuming a capacity factor of 10%, which is roughly the German average) would give us 6.6 TWh.

1.9 GW of wind in one year (assuming a capacity factor of 40%, the average is currently below 30% but I will be generous) would also give us another 6.6 TWh.

Added together we have a total of just over 13 TWh each year from Germany’s new renewables installations in 2011. So, it will take Germany at least 10 years at 2011’s build rate to displace their pre-Fukushima nuclear output with renewables. (note: 10 years of solar additions at 7.5 GW is probably Easter Bunny territory. This will result in over 100 GW of solar on the grid, and will result in Germany having more solar (and wind) than it knows what to do with on a sunny day.)

So, the basic math on Germany’s nuclear phaseout is very clear, yet I suspect that Lovins will not be the last person to try to deny it.

[Update: Amory Lovins has “corrected” my errors in a comment over at Renewables International. Now, I have no problem admitting when I make mistakes and the above post includes one. I forgot to include the likes of new biomass plants in my analysis. This is correctly pointed out by Craig Morris in the article, so you should knock a couple of years off my conclusion.

On the other hand Lovins’ remark once again shows that he is not very good at arithmetic. He claims that Germany lost 41% of its nuclear production in 2011, whereas this is actually the lost capacity. This is the basis for his claim that Germany can replace its pre Fukushima nuclear output simply by repeating its 2011 renewables additions for 3 years. Here are the actual changes in nuclear output, from Lovins’ own piece:

This is a decline from about 130 to 100 TWh. So, the actual lost production is almost half of what Lovins’ imagines it to be. Also, if Lovins’ had paid a little attention to the statistics in his own posts he would recognise his error. He points out that renewables grew from 20 to 23% of German electricity supply in 2011. Adding three percent per year for four years only adds up to twelve percent, a good bit short of the twenty three percent nuclear was providing.

Lovins also inaccurately states in his comment at Renewables International “Since the calculation resulting in TWh / y is not GW, capacity factors are irrelevant to this hypothetical case’s outcome”. Given that his calculation for lost nuclear production was based purely on their capacities he perhaps should have paid a little attention to  capacity factors. All of the remaining nuclear plants in Germany have high capacity factors, almost always coming in above 80% for the year. The same cannot be said for the plants shut in 2011. These were mostly old plants running at very low capacity factors. For example the Bruensbuttal and Kruemel plants had not produced any electricity in the two years before Fukushima. This is why the percentage decline in nuclear production is about half of the decline in capacity.

I could go on, but I suspect the reader has got my point long ago.]