One of the best pieces of scientific news the last decades has been the spectacular improvements in solar energy generation. The current world price was set in 2017 when the Dubai government bought a large future solar contract for 7.3 US cents per Kilowatt Hour, a mere 1/6th of the price in 2010. Compared to the 1970s, solar cells now cost less than 1% of what they were then. Unless you own a coal mine, that counts as great news!
Let’s dream out loud a little as to what this revolution in solar might lead to this century. I expect solar to transform the deserts around the world, and I like the fantasy that solar power will be used to green Australia’s deserts by pumping desalinated water up to the top of the Dividing Range.
Before sharing such dreams, let us first discuss a few technological bottlenecks to wider-scale adoption. A continuing problem for solar is that it is intermittent, meaning that large-scale usage depends on technology to store surplus energy and transport it to and from the areas of generation to where it is used. Both long-distance electricity transport and large-scale storage remain very expensive and very limited in scope at the moment, despite technological advances in both.
As a rule of thumb, you lose 5% of the electricity for every 1,000 kilometres of electricity transport, and even that requires prohibitively expensive electricity lines. That rules out any fantasy wherein Australian solar farms supply New York!
Battery storage has come a long way since the 70s, with of course the big Tesla battery in South Australia showing that you can have large batteries that can turn on and off very quickly, which is important for solar applications because solar is very variable. Yet, even that battery is relatively small and not capable of storing whole days worth of population consumption, and it’s way too expensive as a storage device to allow solar to compete with fossil at the moment for large-scale supply to the grid. It’s current function is to smooth intermittent supply from fossil-fuel power stations, making fossil fuel more attractive!
In case you’re wondering: batteries in the form of ipads or electric cars are basically too small fry to make much of an impact on this equation.
You might think there is some clever combination that solves all problems. For instance, you might fantasise about storing surplus electricity by pumping up water to some high-mountain lake from which you later on draw electricity by having it fall down again. Think carefully about the main issues involved: you lose something like 20% of the energy pumping the water up at the mountain; you need very unusual mountainous terrain that allows you to have two large lakes from which the water tumbles and gets pumped up without much leakage at either end; and if the population is 2,000 kilometres away, you lose another 20% getting the electricity to and fro. All this is quite apart from the installation and running costs of the lakes, the pumps, the solar panels, and the electricity lines. From my reading, such a package is a long way off being commercially viable, and really only a longer-term dream for countries like China that have the requisite mountainous terrain.
The hope of course is that the bottleneck technologies continue to improve. They will have to for solar to replace fossil as the go-to source of energy for the main electricity grid. The same considerations, btw, also go for wind energy, which has seen similar reductions in price. Both technologies are now low-cost enough to be commercially interesting for many applications and in particular areas, but the package is still not quite there yet to knock fossil off its throne. That, btw, is partially because fossil fuel has become a lot cheaper too, particularly since the US and China found vast reserves of shale oil and gas. Hence the world’s carbon emissions are still increasing despite renewables hitting an all-time high of 25% of world energy consumption.
Relevant to this are the current developments in China. In the 00’s, the Chinese government wanted to be independent of fossil fuel rich regions, like the Gulf and the US. It invested massively in solar technology, which lead to huge cost reductions in solar technology, now copied elsewhere. Yet, the Chinese have recently found vast reserves of shale gas and as a result are scaling back their own solar projects, which tells you they don’t think solar is cheap enough to replace gas. When it comes to this sort of thing, the Chinese leaders are a very pragmatic bunch of engineers, so stories of evil conspiracies of the fossil fuel industry are unlikely to have mattered for this decision: costs will have dominated.
Supposing that the battery and transport costs of electricity indeed come down though, the future of solar seems immense. Let’s dream a little.
For one, cheap solar transforms deserts from places bereft of human activity to prised assets for electricity generation. You see, many deserts are near the equator where the sun is the brightest and land in the deserts is extremely cheap since there is nothing much else for humans to do there. So deserts are the logical places to house massive solar farms.
What is currently in the way of a place like Australia filling its deserts with solar farms is the transport costs of electricity and the big-battery issue. When those bottlenecks are gone, the dash for the deserts is on. Places like Australia, Saudi Arabia, but also California and Mexico, would be big beneficiaries. Plenty of cheap deserts in those places where nothing much else happens of high value.
Deserts in Africa and Central Asia could also be stacked with solar panels, but in those cases there is an additional bottleneck, which is that the main users of the electricity would be in other countries, which raises the issue of international politics. Like the oil pipelines that go through many countries, electricity cables that go through different countries would be prime targets for extortion and political in-fighting. The countries in Africa with lots of deserts are very politically volatile and any expensive electricity lines would undoubtedly get sucked into many conflicts, which essentially just increases the price. Central Asia is a bit more stable, but the same problem applies, so don’t expect the dash to happen there first.
The deserts might well be affected by another solar-related change, which is that intermittent availability is not a problem for desalination and water pumps. Hence one of the major processes that is not dependent on the big battery problem, nor even that of electricity transportation costs, is that of desalinating ocean water and pumping it to the deserts to make them greener. It is a prime thing to do with the excess electricity during sunny days, when the price would be close to zero. This too is highly relevant for Australia, Saudi Arabia, and other countries with deserts close to the sea.
In the case of Australia, the obvious scenario is for solar farms to supply the energy to desalinate huge volumes of water just East of the Dividing range, pumped up to the top of the Dividing Range, and then let loose to the West of that range, essentially desalinating parts of the desert and greening the interior. If you look at a geological map of Australia, the most suitable place to pump the water to would seem to be somewhere west of Lismore: from the top of the range there, one could let the water stream via a system of canals to the Great Basin to the North-West and into the Murray-Darling Basin to the South-West.
Admittedly, this is a mere pipe-dream at present, but hej, why not? Building these pipes, canals, and pumps could be one of the major infrastructure projects of the 21st century. Once the technology has been perfected in Australia, it is a good bet the companies would be commissioned to repeat the feat in many other places in the world, so it could become one of our comparative advantages.
Cheap solar unlocks the deserts in another way, which is that it provides the energy for lots of air conditioning, making them much more habitable, though obviously still confined to in-doors environments.
Finally, cheap solar makes the deserts more attractive places for extremely energy-intensive industries, like Bauxite-to-Aluminium processing or big chemical plants.
Then the issue of climate change. Would cheap solar (and wind), combined with cheaper big batteries and cheaper electricity transportation, on its own lead to such a reduction in fossil fuel usage so as to halt the warming of the earth? It would seem the answer at the moment is still ‘no’ for several reasons.
For one, one should always bear in mind that the increased greenhouse gas concentrations in the atmosphere are like a blanket over the earth that only very slowly gets reduced in its thickness if it is no longer added to. By very slowly, I mean that the natural processes that return atmospheric CO2 levels to pre-industrial values take centuries, if not thousands of years. So even if all human emissions were to stop abruptly today, the world would continue to warm for a long, long time yet.
It also remains the case that there is huge regional variation in just how cheap fossil fuel is and that this implies that the whole package containing solar would have to be extremely cheap to out-compete fossil for most applications nearly everywhere. You see, in some places, like the Gulf, the costs of pumping up the oil is almost zero and the only costs borne by the users is that of usage. Even if the solar panels were for free, the other elements (batteries and transport) will often be too expensive to compete with that. In areas with strong winds, abundant sunshine, and less easily available fossil fuels, the relative costs look different.
The convenience of fossil fuel should also not be under-estimated. Fossil fuels are very portable, pack a lot of energy punch for their weight, and of course they have the advantage of the huge existing infrastructure for its dissemination and usage (fuel stations, existing power plants, and lots of combustion engines). Even free solar energy would take a long time (decades?) to flush out those advantages.
You might think that cheap solar (and wind) could out-compete these mobility and energy-per-weight advantages of fossil fuels by, for instance, being used to create hydrogen that would also be mobile and an alternative to fossil fuel. Whilst there too, the technology is progressing, the key problem with hydrogen is that it is so bloody volatile and explosive. Just as you don’t put ammunition depots in the middle of the cities, so too do you really not want large stores of hydrogen anywhere near large population centers. The technology needs to progress a lot to overcome that bottleneck. Remember the Hindenburg disaster!
Finally, there remain applications for which solar (or batteries in general) is not energy-intensive enough. Key among those are aeroplanes and large ships. Those two applications alone would ensure the world continues to pump more new greenhouse gasses into the atmosphere than naturally gets taken out, which essentially means that the world as a whole would just slightly more slowly go through its fossil fuel reserves.
Doesn’t it help if the world burns its fossil fuel reserves more slowly? Basically, ‘no’. From a geological-time perspective, the difference between burning up the fossil fuel reserves in 50 years or 300 years is nigh-irrelevant for the eventual peak in global warming. You would thus still need to do something else than merely slow down the fossil burning if you want to halt global warming (like actively taking out CO2 or geo-engineering).
So technologies still need to improve spectacularly for solar (and wind) to seriously dent the climate change trajectories over the coming centuries. Yet, it would seem that the technologies are getting close to the point where we should expect major effects on our deserts already. Cheap solar should be expected to make them much more habitable and suitable for energy-intensive industries.