The Energy Transition

This is the second column in The Energy Transition series by Robert Wilson. This series, exclusive to, will take a critical look at the prospects of a transition away from fossil fuels, and promises to abide by the advice of Richard Feynman that reality must take precedence over public relations.

Historically energy transitions have been drawn out affairs that took many generations. A rapid transition to renewables in Germany is often portrayed as being a reality. The evidence however indicates an energy transition no faster than its historical predecessors.

What percentage of Germany's energy needs comes from solar power? If you spend too much time reading environmental websites you could be forgiven for believing the figure to be anywhere as high as 50%. The actual figure is 2%, according to BP's latest statistical review of global energy. Wind power fares slightly better at 3.3%. This figures make it rather clear that if Germany is showing how we can get to 100% renewable energy, it has a long way to go. And the rate of growth of renewables is not anywhere close to what is needed for rapid de-carbonisation.  As George Orwell once observed "Sometimes the first duty of intelligent men is the restatement of the obvious." Here I will have to re-state the obvious, and will leave it to the reader to ascertain whether I am an intelligent man.

The basics of German energy

Germany is a rather typical modernised country. It uses oil mostly for transport, coal mostly for generating electricity and natural gas mostly for heating and electricity.

Last year, Germany's total energy consumption was equivalent to 312 million tonnes of oil, generally written as tonnes of oil equivalent (toe). In power terms this is roughly 430 GW. And of this the energy mix was as follows: Oil was 35.8%, natural gas 21.7%, coal 25.4%, nuclear energy 7.2%, hydro-electricity 1.5% and non-hydro renewables 8.3%.

(A brief note: coal and gas are converted to oil equivalent by estimating the amount of oil that would provide the equivalent thermal energy after combustion. We don't burn a fuel to get electricity from wind or solar, so there is always an ambiguity in how to convert energy from wind and solar to tonnes of oil equivalent. The approach taken by BP is to estimate how much fossil fuel on average would provide the equivalent amount of electricity and work out the oil equivalent of this. Alternative approaches exist, however for my purposes here this will give us figures that can be compared on apples to apples basis.) byFuel Despite some growth in renewables, and a decline in nuclear in the last decade Germany's energy mix has undergone much less change in the last decade than in previous decades, a point I will return to later. Natural gas and coal in particular have barely budged in the last fifteen years. Germany

Quantitative projections of future energy demand are rarely worth the paper they are written on. However two trends need to be considered when thinking about future energy consumption in Germany. The first is that per capita energy consumption has been remarkably flat for the last two decades, and may now be in decline. Germany

The second is that German women are not having enough babies - the current average is 1.4 babies per woman - to increase Germany's population in the long run. And this is not a prospect for the future, Germany's total population is already in decline: Population Even under the United Nations Population Division's highest scenario for future birth rate, population in 2050 will stay roughly the same as today. However it is more likely to be significantly lower. projections Large future increases in energy demand therefore are unlikely. However whether Germany will achieve its hoped for reductions in energy consumption remains to be seen. . For now these reductions merely exist on paper, and any considerations of how to meet future energy demand should not assume it will be at a particular level. Wishful thinking is never good policy.

Wind and solar

Let's begin by considering annual growth of capacity of wind farms in Germany. Since 2000 Germany's total wind capacity has gone from 8.8 GW to 31.3 GW, an annual average growth of 1.9 GW. windcapacity As the above graph makes clear wind power capacity has not been growing exponentially. This is very much a linear trend. In fact, surprisingly, peak growth in German wind capacity came a decade ago. The three highest years were 2001, 2002 and 2003: windannualcapacitygrowth For a few years solar power was acting as if exponential growth was possible, rising from almost 0% of German electricity demand to nearly 5% by 2012, and a total capcity of 32 GW. solarcapacity This rate of growth however stalled in 2012, and new capacity additions in 2013 now look likely to be significantly lower than in 2012. Exponential growth has died its inevitable death.

Looking at the annual increases in average power output from wind and solar shows a much more sober reality than the excessive hype regularly pumped out by some of the Energiewende's more enthusiastic promoters. In the last five years the annual increase in average power generated by wind and solar has averaged 0.7 GW per year. This is only 1% of Germany's average total electricity demand of 70 GW. Therefore at current growth rates Germany will not get more than 50% of its electricity from wind and solar before 2050 without a significant acceleration of the build up of wind and solar.   windandsolar The Whole Equation

If we are to stabilise atmospheric carbon dioxide levels at 450 parts per million we will need to see a transition from fossil fuels to renewable energy in the next few decades. This transition will be historically unprecedented in both speed and scale. A key way to measure its progress therefore is to compare it with previous energy transitions. In Germany's case the two most recent energy transitions involved gas and nuclear energy, which commenced in the 1960s and 1970s respectively.

Here are some quantitative comparisons. In 1965 natural gas supplied 1% of Germany's energy demand, and one decade later it supplied 12.3% of Germany's energy. Nuclear power first supplied 1% of Germany's energy  in 1974. One decade later it supplied 6.8% of its energy. Non-hydro renewables first supplied 1% of Germany's energy demand in 2001, and a decade later supplied 7.8% of its energy. The transition to non-hydro renewables is therefore currently slightly faster than that of nuclear, but significantly slower than that towards natural gas. yearsfrom1 And consider that statistic. Non-hydro renewables only increased from 1% to 7.8% in a decade. If Germany keeps that pace up it will have 100% renewable energy sometime a century from now.

As Vaclav Smil has extensively documented historical energy transitions have been protracted affairs that took many generations. The evidence from Germany so far does not indicate that a transition to renewable energy will be any faster than what has come before.