For many years now, it has been clear to the insiders that there is no hope in achieving serious reductions to greenhouse gas emission by means of international co-operation: the incentives to free ride on the efforts of others is too great and none of the big players is willing to subjugate themselves to a world police that would enforce a deal. So whilst we have all been happily increasing our consumption of fossil fuels year-on-year, the smart money was always on finding some technological fix to global warming that did not require near-unanimous international agreement, whilst simply adapting to the problem in the meantime. That fix could be geo-engineering or a renewable energy source becoming economically competitive with fossil fuels.
So, where are we currently when it comes to geo-engineering and renewables? In terms of geo-engineering the likes of Bill Gates, Richard Branson, the UK Royal Society, and a whole set of EU-US based institutions have been pouring money and time into looking at what can be done. In terms of renewables, the big movers have been Chinese companies and a glut of new ideas that are leading to much cheaper forms of solar power.
To start with solar power first, according to the Bloomberg New Energy Finance’ Solar Value Chain Index the costs per Kilowatt-hour of solar has reduced around 50% in the last 3 years alone, with various new technologies that have the potential of going down much further. They are talking about printing off solar cells, using iron guns to produce them, making solar panels out of a spray-on paint, and various others ideas. One needs to be an expert at this to judge whether it will actually work, which I am not, but the clear reduction in costs that was achieved recently is there for all to see.
So how close is solar to being competitive to fossil fuels in terms of producing for the electricity grid?
As a rule-of-thumb, the life-time costs of the cheapest fossil fuels are currently around US 65 dollars per Megawatt-hour whilst solar was still estimated to minimally cost over 200 dollars per Megawatt-hour in 2010. The cheapest fossil fuels are natural shale gas, natural gas turbines, and some forms of coal. Allowing for a halving of the fixed-cost of solar infrastructure in the next year, solar would still cost above 100 dollars per Megawatt -hour. This is competitive with many currently used forms of electricity generation of fossil fuels, including conventional combustion engines with a cost above 120 dollar per Mwh.
What is important to note is that the current trend of solar prices doesn’t have to continue for long for solar to be the stand-out cheapest form of mass-electricity generation for countries with a lot of sunshine. At the moment solar is hence looking like a real potential long-run replacement for many countries. Even at today’s costs, solar would only be marginally more expensive than fossil fuels.
But what are the inherent disadvantages of solar? Well, for one, you need a lot of solar panels to get a decent electricity flow, so cars or planes with solar cells are nowhere near a realistic prospect in terms of mass-transportation. Hence fossil fuels remain the front-running source of energy for our cars and planes, which on their own are enough to guarantee sufficient demand to keep increasing atmospheric CO2 levels.
Also, it needs to be sunny in order to get electricity, which is a problem for a lot of our economy which is reliant on guaranteed energy flows at any time of the day and where people don’t want to have to reboot their computer after every cloud. Since most of our energy needs are connected to industry or in activities that could run on batteries charged up when the sun shines (like charging up the car and the i-pad), there is some mileage for weening ourselves off this ever-ready energy pattern, but it would seem fair to say that it would be hard for us to adjust to only engaging in major economic activities when the sun shines. Hence a remaining technological hurdle is how to store solar energy easily and in sufficiently huge quantities as to allow for a lack of sun for a few weeks. Given the huge amount of constant electricity demand, this big-battery problem still prevents us from adopting solar as our steady supplier of electricity. If we would have to keep relying on fossil fuel generated electricity when the sun doesn’t shine, which would be the current reality if we’d adopt big solar farms for our electricity base-load, then once again we are guaranteed continued increases in the amount of CO2.
One might object to this by saying that in a large electricity grid one can connect the grids of different countries and thus effectively share sunlight with other regions, but electricity transportation over large distances has a remarkably high loss-rate. As this old Global Energy Network Institute report estimated, every 1,000 kilometers of extra distance increases the costs by around 5-10%, or equivalently that there is about a 5-10% loss in electricity when having to transport it another 1000 kilometers. If one then reflects on the fact that the distance between Sydney and Perth is already close to 4000 kilometers and thus involves a 20-40% loss of electricity, it is clear that it probably is not even cost-effective for Australian states to ‘share’ their sunshine, let alone to share sunlight with other countries.
Hence the problem of energy storage is a serious one for solar and we are still waiting for improvements in battery-efficiency to consider solar as an alternative to the fossil fuel electricity generators which can deliver power whenever we need it. This problem of course also besets wind-energy, for which the prospect of large future reductions in costs is much less rosy.
Furthermore, solar panels need setting up and they have to be kept clean, things that become much cheaper to do if one is setting up many of them in a single spot. Hence solar is unlikely to replace combustion engines as a means of delivering local energy or energy to residential homes: too much hassle and only viable with subsidies or in places where it is hard to get constant supplies of fossil fuels. Some major structures like large boats and sky-scrapers are a different matter though, so one should expect more medium scale uses of solar, although there too the problem of energy storage is a major one.
In short, the price reductions for solar is exceptionally good news for our way of life: given the big price reductions that bring solar close to parity with existing fuels, and given the near inexhaustibly huge supply of solar (the sun sends about 6000 times more solar energy to us than we humans generate from all sources), the future of our industrial modern societies based on cheap energy looks very bright. We might have to adapt to the intermittent nature of the energy flow if we can’t crack the energy storage problem, but at least we now have a liveable alternative. The substitute source of energy to fossil fuels is hence in sight even though it may take a decade or two before its better than what we currently use.
Then the topic of Geo-engineering. Since the landmark 2009 report by the Royal Society (which I extensively reviewed previously), engineers have been dreaming up a lot of new stuff, with particularly hopeful possibilities in the area of Solar Radiation Management (SRM). Front-runners are the ideas of spray-gunning the atmosphere in order to create more clouds, and sending dust particles up into the air.
The spray-gun idea is of a charming simplicity: clouds are white and reflect a lot of sunlight. Hence if you can create yourself more clouds, you cool the earth. How do you create more clouds? Well, clouds are made of water vapour. That vapour arises naturally from the sun heating water, but you can also try to do it yourself by putting water into a plane and delivering the vapour into the atmosphere where you want it (Neukermans A, Cooper G, Foster J, Galbraith L, Ormond B, Johnston D, Wang Qin (2011). Supercritical saltwater spray for marine cloud brightening. Geophysical Research Abstracts, 13, EGU2011-9655-1).
The technology hence has many potential advantages: because one would be in the business of creating thousands of clouds every day, one gets a very sensitive instrument for geo-engineering. You get to decide where you want to cool, just at what temperature you are going to stop cooling, and one can easily experiment with small regions without seriously upsetting the balance of the planet. After all, Nature experiments with clouds all the time and a few more or less wont unbalance the earth. So the technology can be safely tested and experimented with and has great advantages in terms of timing and delivery.
What are the problems? Well, for one, we don’t quite yet seem to be able to produce a fine enough mist quickly enough. After all, you want to be able to do this quickly and thus convert thousands of liters of sea-water into a cloud in a matter of minutes. Yet, sea-water is salty and thus corrosive, and there are all kinds of things in sea water that would clog up any tiny holes. Nature solves this by simply heating the water and thus having salt-free water molecules rising up in the air, but that solution is not open to us because the sun warming the sea water was precisely the problem we are trying to address, not add to. Hence we still need to sort out the problem of quickly filtering sea water and misting it.
A secondary problem is sheer coordination: if we end up with thousands of planes misting the atmosphere then one would be looking at a whole network of airports and cooperating countries. The countries most suited, i.e. close to the North Pole, might actually discover they don’t want to halt warming and thus fail to cooperate.
The bigger problem is that it might not work: aeroplane delivery of water-vapor is an intriguing idea but there are only computer simulations that suggest it is do-able at reasonably low costs. The computer models can easily be off by a magnitude of 10 or more in terms of how much cloud needs to be created to get enough cooling. Just think about it: if we would have to create 10% more clouds in the world, we would be talking about an artificial vapour with the size of America. That’s too much vapour and planes to realistically be able to muster, so one has to hope that it would require no more than a hundredth of this area. I am personally skeptical on this point and would thus not be surprised if some new computer model in the coming years would say it’s a hopeless plan, but we will see.
Then the dust particles, also known as dimming, or ‘aerosols’. I have written about this before and the advantage of this one is that it’s a proven technology. Volcanoes proved it for us. The Mt Pinatubo eruption in 1991 caused a global cooling by belching huge volumes of dust particles into the atmosphere, proving that dust can cool the earth.
Despite some people saying we don’t know how to dust the atmosphere, we humans have also done it. Until about 20 years ago we put a lot of dirty particles into the air by having dirty coal power stations, unfiltered car exhausts, and various other unfiltered industrial emissions. This lead to large-scale dimming to the extent that the amount of sunlight hitting the earth was reducing by up to 4% per decade from 1960-1990.
What happened to dimming? We started to clean up because of concerns over the local environment. People don’t like smog and haziness in their own cities, so governments have mandated industries and electricity generators to clean up and no longer send particles in the air. This has reversed the global dimming trends, such that our days are once more full of gloriously clear sunshine. And quite probably also means global warming is resuming on a faster upward trajectory.
It is not too hard to guess what can be done: by re-adopting our dirtier ways we can resume the dimming process. Furthermore, there are scientists trying to perfect what we stumbled upon by accident. We can make the dust we send up more reflective, more buoyant (so it stays up for longer), less degradable, and less annoying to people.
The big problem with this solution is again one of sheer scale: when we were dimming we were belching up an awful lot of stuff into the atmosphere. We were effectively blocking out an area the size of Australia and we were still warming up the planet! It is even worse: since then we have added a lot of extra Greenhouse gasses, meaning that we’d have to take dimming to an extra level to be of potential help. To make an impact, we’d have to re-designate large areas that we don’t care about, such as, say, the Pacific Ocean, as dimming territories and continuously belch up huge volumes of dust. That in turn requires a massive industrial exercise since it would involve sending huge volumes of resources to tiny island in the middle of distant oceans in order to send it up. It is not at all clear yet that this is affordable in terms of what we are willing to pay to stop global warming (which is not much).
Summarising, geo-engineering is probably do-able though we don’t yet know the true costs. We can safely assume it would be minimally in the order of hundreds of billions of dollars every year. And the uncertainties are such that we are easily 20 years off knowing enough to be able to implement it. During that 20 years, we can safely say that we will keep going through the cheapest energy sources – fossil fuels, whilst solar energy is promising to be the go-to source once the cheapest forms of fossil fuels have run out. If improvements in solar and battery technology are spectacular, it may even muscle out fossil fuels within this decade as the major provider of base-load energy.
In short, there have been very hopeful developments for the sustainability of our current way of life on this planet in the last 2 years.