We are constantly being challenged to change or degrade our lifestyle to conform to what is called a more sustainable energy lifestyle – but have we ever stopped to think about the energy sources we depend on and where they come from?
Here in Ontario a significant portion of our electricity comes from hydroelectric generation – water falling through a turbine that spins a generator. The water is falling under the influence of gravity, having been carried into the clouds and fallen back to earth at a higher level due to solar heating and atmospheric circulation. As long as the rain falls from the sky there is the potential for hydroelectric power generation.
Many parts of the world depend upon the combustion of coal to produce heat that almost always produced steam to spin turbines that turn generators. The combustion process requires oxygen – the byproduct of plant metabolism driven by the sun, much from the huge forests that once covered most of the continent (but our lumbering folks are working hard to fix that). Coal is the remains of ancient plants that got buried for a long time. The process continues today in the peat bogs of the world. Is coal burning sustainable? Perhaps, but only if our consumption does not overrun the rate of generation – which I suspect it does. But there is a lot of it to burn… as long as there are plants to make the oxygen the process requires.
So instead of coal, many industrial processes burn natural gas or petroleum. We have pretty much built our whole civilization around this stuff. We seem to fret a lot about running out. After all, not only is this a high energy fuel but it provides the basic chemical feedstocks for many of the synthetic products we use and wear. And we keep finding new sources although each is more difficult and problematic to get. And where does it come from? The theory I like is that this stuff is sea floor sediment that has been subducted and cooked in the earth for a long time – if so it continues to be made as long as the continents keep wandering. Are we overrunning the rate of production – be nice to know. But we do keep finding new sources of it — the latest is ‘fraking’ of sedimentary rocks. Personally, I think this stuff is far too valuable as a feedstock to burn. But the big money is on the side of burning it. And so far we have plenty of plants to produce the oxygen we need for combustion (and breathing).
Eco-terrorist organizations back extensive deployments of wind turbines as a sustainable source of energy. As long as the sun shines and heats the earth, making the wind blow, we should be able to produce electricity. Well, that is the theory anyhow. The rub comes from how industrial wind turbines are used. If I put up a wind turbine at the house to offset the rising costs of electricity, I would need to have a battery bank to absorb the wildly variable wind-produced energy and trickle it back into the appliances that are quite intolerant of voltage fluctuations.
But these huge wind farms have no batteries – instead the province is provisioning backup power with an extensive buildout of natural gas-fueled generators. So when the wind dips these things can spin up quickly and keep the province from going dark. This can only be done by keeping the turbines spinning and hot all the time – so what is saved by wind generation is made up for by the burning of natural gas. And we will ignore the huge energy costs of the cement, fibreglass and steel that makes up these behemoths. And also the environmental destruction caused by placing them in bird sanctuaries and migratory flyways – but what are treaties when there is money to be made? These things are touted as sustainable but their use is heavily dependent on burning natural gas – a small detail that is usually ignored in arguments about a sustainable energy future, whatever that really is. And lets not forget the green plants… And they are not without their side-effects as well — downwind of the turbines it gets drier and warmer due to the enhanced mixing. The long range climate impact of this is not even in anyone’s’ climate fantasies — yet.
Solar photovoltaic is the other darling of the eco-terrorist. Ontario has rich subsidies for anyone willing to cover acres of prime farmland with these passive converters of sunlight into electricity. Besides the loss of the land to other purposes, there is the manufacturing process for solar panels that is immensely energy intensive and has been rumored to release byproduct gases that are vastly greater heat traps than CO2 and methane. And another downside is that even though the sun is lavished on us at almost 1kw per square meter, the conversion efficiency of sunlight into usable power is roughly 10%, so huge areas are needed to produce provincially meaningful amounts of power.
Wind and photovoltaic power sources are relatively low density – any power production requires huge tracts of land. And to offset the regional variability these sources are widely spaced. This increases the need for expensive long distance power transmission lines to move the small amounts of power generated. The theory is that if the wind is not blowing one place it is blowing someplace else, same thing for cloudy skies. Problem is that Ontario is much too small – the wind fluctuates similarly from one end of the province to the other and often blows hardest when power demands are low. And there are two issues with the long distance grid – transmission losses and management complexity. The computer industry is sure that the ‘SmartGrid’ will fix all our problems — substituting technology for the human element that so far has struggled to manage complex grid interactions. May not fix them but someone will get rich… And these huge cats cradles of transmission lines are susceptible to induced electric loads from geomagnetic storms. There is an interesting recent study from Germany http://phys.org/news/2013-04-turbines-great-turbulence-consequences-grid.html that suggests that wind farms amplify wind variability rather than damp it out. Like so many other things it would seem that the averaging out of variability was a theory that no one bothered to check.
Nuclear provides almost half of the electricity for Ontario. Strangely, this is not considered a sustainable energy source, but I would suggest it really is. Nuclear fission uses the accelerated decay of heavy elements to produce heat – generating steam that is used in the same way as in coal-fired generators. No oxygen is required for this process, it could run in a vacuum or underground. And where do heavy elements come from? They are common components of the earth but like everything else that makes up this world come from (very) ancient supernova explosions. For a while there was some interest in breeder reactors that produce more fissionable material than they consume – but this technology has largely been shunned because the product could be used to make bombs as well. Same thing happens if we chose to reprocess spent fuel. So instead we crud up the fissionable material through use and then want to throw it away as nuclear waste but are so panic stricken about it that we make transport difficult and reprocessing almost impossible – so subsequent constructive uses are ignored. And the spent fuel piles up in the reactor buildings — turning small problems into big ones over time. The issue will be forced eventually, the only question is how and at what cost — and I do not mean the costs of an orderly, planned process but more like the mess that was Fukishima. My simplistic view on nuclear power is that it is in the same position as steam was early in the industrial revolution — everyone recognizes it as a powerful source of energy but there are a lot of hard lessons to be learned to use it safely. It may also be relevant to consider that there are lots of small, highly reliable reactors in use as powerplants for ships — perhaps small really is beautiful and we have gone well astray in seeking to build huge reactors when we really only understand little ones?
The common factor for hydroelectric, nuclear, combustion, wind and photovoltaic power generation is the sun. Combustion processes are ultimately solar because they need organic matter, mostly from plants, to produce the fuel and oxygen from plants to drive the combustion chemical reaction (and a lot of time to transform the plants into the forms we use). Photovoltaic processes produce electricity by capturing the incident sunlight (at 10% to 15% efficiency) – but like wind, large scale direct use without batteries to modulate the variability requires backup power. And hydroelectric and wind require the sun to warm the earth, driving evaporation and air circulation as long as there are large scale temperature differences. As the earth warms these differences will get smaller over time. Studies show that winds around the Great Lakes are gradually diminishing over time as the planet warms – somehow that makes me wonder just how ‘sustainable’ wind and hydroelectric power are if we are messing with atmospheric circulation? And the fuels nuclear needs is replenished every time a supernova blows… renewable, but only if you are immortal, I suppose.
Fossil fuels are probably ‘sustainable’ as long as there are plants, oceans and continental drift and we chose to ignore their atmospheric side effects. Problem is that like the folks with the goose that lays golden eggs we seem to want everything right now. So pacing our consumption to not overrun the rate of generation is probably asking too much. And since we keep pushing the population upwards even the rate of consumption is increasing. And all these people want to live in cities so the farms and forests are getting paved over and cut down – so fewer places for the green plants so essential to the generation of oxygen that we and our combustion processes depend upon.
There has been a lot of enthusiasm for fossil fuel replacements — ethanol in gasoline and other examples. Problem with all of these is that the overall energy cost of producing the fuel is substantial, more than the base petroleum distilate. And if we really care about saving the planet, does it really make sense to replace one combustion process with another?
Nuclear power could provide the energy that we need with few environmental side effects. There are no combustion byproducts to contribute to climate change. And through breeders and waste reprocessing the amount of the planet that would need to be pillaged could be greatly reduced. And we should not forget a few details. Fission reactors are natural and have been found to have existed in African for millions of years. Fallout is very dangerous to be sure but we all survived the results of hundreds of open air nuclear bomb tests in the 1950s and 60s. The problem with the technology is that it is all so new. The self-created panic over nuclear technology has slowed development of better ways to use it. We have forgotten the hundreds of people who died as engineers learned to build with iron and steel, control steam or fly though the air. None of the technologies we rely on achieved their current state without pain. And if we ever overrun our supply of fissionable materials there may be a bit of a wait until the next supernova explosion replenishes our supply. And whats worse, the shipping charges would be enormous.
If we consider the definition of sustainable as anything constant and long lasting that will not be compromised by the changes we are making to this planet, the only real answer is the sun. Or more precisely, the process that the sun uses to create its energy – nuclear fusion. The process is simple – one takes two or more light elements like hydrogen or lithium and mash them together with great force, fusing their nuclei into heavier elements. This process releases energy in huge quantities – look up at the sun some day or see a film clip of a hydrogen bomb explosion. The fusion process makes the sun glow and sparkles the night sky. And it goes on and on, making heavier elements out of lighter ones until everything we see around us is created. But there is a slight problem – the sun uses the gravity produced by its gigantic mass to achieve the temperatures and pressures needed for fusion. On Earth it is a bit harder. Folks have been working on this for the last 60 years or so and have been able to create the right conditions for a short time using a fission bomb as a match or for a brief instant using some very fancy equipment. I recall an announcement a few years ago that the hottest spot in the solar system was in a lab in New Jersey — their fusion reactor had achieved for a brief moment temperatures higher than are thought to exist in the core of the Sun. For a brief moment it made me very happy. Exciting stuff but a very long way from power generation. And one other dark thought — the light weight elements that fusion consumes come from the origin of the Universe itself, currently called the Big Bang. So we could run out and short of another ‘Let There Be Light!’ there would be only darkness.
I seem to recall that the original concern for sustainable energy production was so our society would not go dark when we ran out of coal, oil or gas. A noble goal to be sure. Energy is a precious resource and should not be wasted. But our technological infrastructure requires a steady diet of power within fairly narrow bounds – something that wind cannot achieve without a lot of combustion-powered backup power. So perversely we are probably burning even more fossil fuel to support the illusion of sustainable power. Nuclear could do it but as a society we are running away from it. And fusion power is so far away that it is still on the boundary of science fiction. So we are doing for electricity what we did with automobiles. In order to reduce the consumption of gasoline in cars we added ethyl alcohol – currently around 10%. Ethyl alcohol (ethanol) is made by crushing, fermenting and distilling corn – a process that has a steep energy cost of its own. And cars burn gasoline with ethanol are less efficient than on pure gasoline. It may be worth remembering that this idea first came about in the 1930’s as a means of increasing corn consumption. So in the end, some farmers are happy, but more gasoline than ever is being burned.
Being Green or being sustainable — the real question is what are we trying to achieve? Civilization as we know it is a huge consumer of energy. If we really want to save the planet there might be some virtue in technologies that produce large amounts of energy with minimal planetary heating. But the greenies, the eco-terrorists, are working to replace one combustion process with another. Not a path that will change what is happening to the planet.
Even electric cars do this — somehow the power has to be produced that the electric car uses. So one might consider these things coal, wind or nuclear powered cars. And the batteries they require have technological consequences of their own. So are we really that much better off with an electric Prius or a gasoline powered behemoth? I am not sure the real answer is that clear.
Our approach to sustainable energy seems much the same – what we are doing is more inefficient and wasteful but we keep doing it because it is ‘green’. And being ‘green’ is used to justify a lot of abuse — look at the way Ontario is ramming wind farms down the throat of rural communities. Actually looking at what we do is just too much to ask. Somehow the dystopian scifi authors are probably wild optimists.