By Phil Kreveld
Some hate renewables, others preach the end of life as we know it if we don’t replace all coal and gas. These opposites in views are exploited by partisan politics. More than likely renewables and fossil fuel-based generation will be needed for the foreseeable future.
The Iran war illustrates that without a steady supply of fossil fuels we are heading for trouble. A well-documented article by Chris Uhlmann in the Australian of 3-4 May makes the case for fossil fuels strongly. He states that Germany, once an enthusiastic adopter of wind and solar, now is reverting to fossil fuels and regretting the closure of its nuclear power stations. Uhlmann is a critic of Australia’s renewable transition. It is tempting therefore to dismiss his views if one is on the opposite side. But it is also possible that he and the backers of the renewable transition are both justified in their views, if not to their extreme limits.
Related article: Is the renewables transition in dire straits?
First let’s review the quotes of Germany’s Economic Affairs and Energy Minister, Katherina Reiche, as reported in The Australian.
“Let us look at the facts: Germany has a total energy demand of 2900TWh for electricity, heating and industrial processes. Just one sixth of this is electricity, and more than half of that comes from renewable energy. However, the share of renewables in total energy consumption in 2025 was only just under one-fifth.”
“For years, we have comforted ourselves with ambitious targets. Eighty per cent of electricity from renewables by 2030, climate neutrality by 2045—fine figures that soothe our conscience. But while we clung to these targets, electricity prices exploded.”
“German households pay up to 37c per kilowatt hour—more than 9c above the EU average. Our industry is bleeding. Deindustrialisation is accelerating.”
“Yes, wind and sun do not send a bill. But the overall system certainly does: (environmental levies), capacity reserves, grid dispatch costs, grid balancing, subsidies to lower energy prices—all of this adds up to system costs of more than €36bn ($58.6bn) per year. That is €430 for every German citizen.”
“We pay almost €3bn alone for curtailing wind turbines and solar plants because the grid cannot absorb their electricity. There is no other industry that receives guaranteed financing for more than 20 years and is even compensated when its product is not needed. This cannot continue.”
“One fact has been suppressed for too long: an energy transition that ignores system costs will ruin the country it claims to save.”
The comments by the German Minister deserve attention. We cannot ignore them—but to understand that geography makes a difference. European costs for electrical energy on average appear to be 40% more than in Australia. And, we must assume, also including subsidies.
There is room for a reasoned and balanced analysis. To dismiss fossil fuels so as to attain ‘Renewable Nirvana’ the sooner, the better, is silly. To dismiss our Australian sundrenched bit of the earth as an innate source of renewable energy is equally silly. Costs are important and Australia is no exception to Germany in subsidies for electrical energy—and rethinking the necessity of these to encourage further uptake of wind and solar.
Berlin, the seat of the German Government has an average insolation 137W/sq m, latitude of 52.3° North and midsummer sun elevation angle of 60.9°; Canberra has an average insolation of 320W/sq m, latitude of 35.3° South and midsummer elevation of 78°. Based on a flat roof Canberra will have 260% more available solar energy than Berlin. In other words, we must pay attention to the facts from Germany, but we are in a better situation, solar energy-wise.
When we think of energy, it is really the transformation of energy rather than innate energy. The latter only serves us if we can get it to flow, i.e., power (energy/time). Conversion efficiencies vary greatly and fierce battles over conversion efficiencies of coal, nuclear, hydro, wind, and solar are mounted to destroy or defend renewable sources of energy. If we forget about saving the planet and concentrate on the one and only (with the exception of nuclear energy) source of everything we can lay our hands on, it’s the sun. Its surface temperature is 5800°K. We’re at around 300°K on the earth’s surface. If we utilise that temperature difference directly, we can have a conversion efficiency of 95%. The Shockley-Queisser limit of photoelectron conversion efficiency limit is 33.7% although it varies with bandgap energy of photocell material. We can double that by cooling solar panels and utilising the heat for heat pumps. The combination of the sun and revolution of the earth provide mechanical power, the wind (between 1 to 2%, at maximum figure of 17W/sq m—too low for practical use, but there are many highly productive wind energy areas to exploit.
The fossil fuels we can dig up took between 50 and 350 million years to form, utilising the sun as primary energy source. As we exhaust the top layers, we have to dig deeper and deeper and take up more of the earth’s surface, therefore costing more energy to dig up or to pipe it from the bowels of the earth. Were we to drop the ‘gold standard’ and derive a ‘Joule standard’, we might yet become more aware of what the true cost of so much energy is in our modern economy.
This is not to dismiss Uhlmann’s article because he’s on the money regarding our continued reliance on fossil fuels—and on its importance in the foreseeable future. However, we can walk and chew gum at the same time, i.e. increase petrochemical storage and refineries, dig up coal and gas and work on the renewable transition, because it is also a very sensible measure. We are already far advanced in the penetration of wind and solar, and will not unwind this investment. However, it is a fact that the people who understand the technical difficulties of 80% renewables do not opine in the public forum. This gives the rest of us the opportunity to belt each around the ears, yelling “troglodyte”, or “leftwing greenie”, without adding to sensible discussion.
Related article: King Cnut and the solar tides
Take for discussion the following proposition; convert some coal-fired power stations to high temperature operation, for running at a low, 24-hour baseload. All other load-following energy would come from renewables/batteries, situated close the power station buses, all operating on phase-locked loop basis. That would simplify technical challenges greatly and call into question the need for some remote energy zones. Note: this illustrates what we could have done a decade or longer ago, thinking through the problem from a total system aspect. Before we beat ourselves up for having missed the opportunity there is consolation in the knowledge that most infrastructure ‘planning’ is ad hoc. To be realists, it’s way too late now and rather than being purists our job is to create a 24/7 grid with constant voltage and frequency—that is our only job. That requires accommodation of gas and coal—don’t let the desire for the perfect spoil the opportunity for significant advances in CO2 abatement.
And a cautionary note to the renewables enthusiasts, brooking nothing else but ‘confidence is what you have when you don’t understand the engineering problems’ and they’re not yours to solve.
