Could we run our society on renewable energy sources, which now deliver electricity cheaper than fossil fuel produced power? Vaclav Smil has just published figures on Germany’s efforts to move towards a high penetration renewable system, showing that the cost is likely to be very high.
After the Fukushima nuclear accident Germany decided to close its nuclear reactors and cut back on fossil fuel uses by making an enthusiastic commitment to renewable energy sources. For some time Smil has been warning that the shift to renewables will be more time consuming and difficult than most people think. He has just drawn attention to some data summarising Germany’s achievements over the past twenty years.
In 2019 Germany produced about as much electricity as in 2000; only 5% more. In that period renewable generating capacity rose by 80%, but the amount of electricity generated by fossil fuels fell only from 84% to 78%. The addition of renewables didn’t replace fossil fuel use, renewable sources were added to the existing generating system, which had to be largely retained to deal with the intermittency of the renewables.
Smil says Germany now has two systems, a renewable one which supplies 41% of electricity demand and a fossil fuelled one which has to be resorted to when the renewable input is down. This means the capacity factor for the fossil fuelled system is low, increasing the cost of its input. “Germany needs to keep the old system in order to meet demand on cloudy and calm days and to produce nearly half of total demand.”
Smil points out that if the building of renewable capacity continued at this rate fossil fuels would still be “ … providing nearly 70 percent of the country’s primary energy supply in 2050.”
The result of this situation is very expensive power. Smil says the cost of electricity in the US is 13 cents per kWh, and in Germany it is 35 cents per kWh.
Europe can experience weeks of continuous very cold, calm and cloudy weather in winter. Germany’s situation would be far worse if it could not draw on Scandanavian hydro storage capacity or French nuclear plants when renewables are down, or export surpluses to other countries. Smil says that even now there are times when 90% of the renewable output has to be exported or dumped. The extent to which intermittent input varies is easily overlooked.
Thus the essential question for advocates of 100% renewable energy supply is not can it be done, but at what cost. Australia has hardly any backup/storage problem to deal with at present. Germany has found that to deal with the problem required building a renewable system as big as the existing fossil fuel system. The amount of back/storage capacity needed to deal with intermittent sources escalates rapidly as the renewable contribution goes from 50% towards 100%.
Australia’s renewable sources are much more favourable than Germany’s, but the same issue remains; how much redundancy and storage at what cost would have to be built, to achieve high penetration or total elimination of carbon-based generation? This cannot be answered without many more “simulation” studies which attempt to work out what pattern of renewables based at what locations could meet demand all the time, at minimum cost.
These studies are difficult and costly, and vary significantly in conclusions. Few have been carried out for Australia. Unfortunately findings vary significantly with assumptions, and all involve uncertain and challengeable assumptions. My impression is that a reliable high penetration system using Andrew Blaker’s pumped hydro approach to storage might be feasible, but at what cost? The point is that we are far from settling the issue.
But all that is only about electricity supply, and that’s the easy task. About 80% of energy needed at present is not in the form of electricity. Converting from electricity to other forms of energy is very costly in terms of energy losses, plant required and thus dollars. If you want to provide transport fuel for instance via hydrogen or ammonia produced from solar panels then each kWh of energy reaching your vehicle’s wheels will require PV or wind sources to generate about 5 to 10 kWh of electricity. Even if we transformed as many functions as possible to electricity, e.g., light vehicles, my attempt to work out the amount of generating capacity needed concluded that the total cost would be far beyond affordable. We need more studies of that kind, that is, dealing with the total energy economy.
So the fact that a kWh of electricity can now be produced more cheaply by renewable than by fossil fuel generation is misleading. It tells us little about the cost of producing it by a system that has so much backup and storage plant that demand can be met all the time. Germany’s experience shows that the energy problem is much more difficult than the typical greenie realises.
The answer to the energy problem, and all the other big problems now threatening our existence including resource scarcity, environmental destruction, resource wars and crumbling social cohesion, is not to be found where they are looking for it, that is on the supply side. This society is far beyond sustainable levels of resource consumption, yet its supreme goal is to constantly increase living standards and GDP without limit. The solution can only be found on the demand side, that is, by shifting to much simpler lifestyles and systems.
This is not an argument against renewables. We must move to 100% renewable energy supply as fast as possible … but there is a strong case and many analysts arguing that we cannot do it unless we abandon the suicidal quest for limitless affluence and growth. This is increasingly being understood; at last we now have a global ‘de-growth’ movement.