Power generation options (J Sandison)
In light of the furore about the windfarm, I thought it worthwhile to consider all generation technology, to see how they compare with one another, and what options there are. This is a brief overview; to give detailed coverage would take an encyclopaedia.
The continued use of coal, oil and gas are well documented. Assertions about hydrocarbon fuel stretching into the distant future are not entirely correct. Oil has a very limited affordable lifespan of only a few decades. There is a lot of shale gas being found and exploited, and it will last longer than oil. However it also has its problems. Look at the vociferous anti-fracking lobby, with worries about health, ground water contamination, earthquakes, etc. To convert the world from running on oil to running on gas will take a huge commitment of time, material and effort. Another problem is security of supply, a (possibly literal) minefield.
An anti-windfarm argument used by some is “we would be more supportive if it would give us cheap electricity”. It may not seem like it, but we get cheap electricity now. If we were paying the true cost of generating our power by the old oil-fired Lerwick Power Station we would be paying twice what we currently pay. We are, in effect, heavily subsidised by mainland electricity customers.
Waves, like the wind and tides, are not constant. The available power from a wave front is – per 1 metre length – from about 15KW for a 1 metre high wave to about 1.7MW with a 30 metre high wave. To handle this huge variation requires robust engineering, both to produce electricity and to survive. The amount of energy is also variable depending on the angle to the generating device, so fixed installations on shore are inefficient.
There is scope for more of these, but suitable locations are scarce, and they are expensive. There are the usual environmental objections.
This is a proven technology, with well established working examples. Very limited locations where it is feasible. Again there are environmental concerns. Remember the groundswell of opposition at even the hint of a Severn barrage between England and Wales.
Tides, as with wind and wave, are variable. They are predictable, not always available at convenient times. They only produce useful power for about 18 hours a day, due to the slack water periods. Not efficient. No proven good designs, still very much experimental.
Thorium (MSR) and (LFTR) reactor
These related technologies have been nominated as the “great green hope” for the future. Unfortunately it has never been made to work on a commercial scale, although many countries have tried, and are still working on them. There are substantial technical problems associated with this technology. Still a next generation technology is extremely costly and requires subsidy. These problems are highlighted by the fact that none of the big power generation or nuclear players have shown much interest as it should be a great bit of PR for them to declare a safe nuclear generation option. It is also not as safe as it at first appears, creating some radioactive waste with disposal still a problem. Don’t hold your breath on this technology either.
There is potential here, alas not problem free. Not efficient for Shetland latitudes. In midwinter when we really need it, the sun just manages a few degrees above the horizon daily for a few hours. There are solar furnaces operational in various parts of the world. There are speculative plans for solar furnaces in the Sahara producing power to feed Europe and elsewhere via interconnectors. This is purely theoretical.
Considering that the world human population reached seven billion last year, and will reach nine billion by about 2050, every suitable bit of land will be required to grow food, never mind growing fuel. This is a complete nonsense, ensuring more poverty and starvation in the future. It is heavily subsidised.
A well understood technology in widespread and ever growing use. Very good for base load, but has a problem with waste disposal, and the nuclear weapon potential. Has bad PR profile due to its association with the atom bomb, and the Three Mile Island, Chernobyl and Fukushima accidents. Out of favour at the moment, nevertheless it has its place in the mix. Heavily subsidised.
Already receiving intense scientific and engineering investigation. Safer than the fission process as it cannot go into meltdown, unlike fission reactors. There is less radioactive waste, and hydrogen is the fuel. Unproven commercially. Extremely costly, subsidy required.
I believe that the UK government is instigating talks with Iceland this month (May 2012) with a view to constructing an interconnector between Iceland and UK, to make use of Iceland’s geothermal energy for power generation. There is certainly potential for this technology.
Will have its place, but again requires lots of power to obtain hydrogen from whatever medium is preferred for extraction.
Artificial photosynthesis and algae
More theoretical technologies, under investigation, both still pipedreams.
This is a proven technology, unlike a good proportion of the above. Suffers because the wind is not constant, and from their size. I have recently been aware of a cry to wait and see, wait until generators get smaller. Unfortunately the laws of physics will dictate how much power can be derived from a given size of machine. There will be an irreducible minimum, which every design is subject to. In other words you can’t get something for nothing.
It would be great if we could find a fairy godmother, willing to wave her magic wand to give us endless energy, with no climatic, health or environmental consequences. The reality is that such an outcome is purely that – a fairy story.
It seems to be a habitual throwaway line by anti-windfarm proponents to say “we don’t need windmills, we have plenty of wave and tidal power”.
Yes we do have plenty of wave and tidal power, but we have neither wave nor tidal power generation. Even if we do in the future, there will still be a need for converter stations and interconnectors to make use of it. If you think that the Viking windfarm investment is expensive, just wait till you try to develop wave and tidal power generation purely for Shetland, without an export interconnector.
The fact that all these ideas are being examined is an indication of what a serious and growing energy problem the world has. Unfortunately all energy sources have their own problems.
We will need a mix of all or most of the above to get best value with least associated damage. There will be similar objections to each and every proposal, whatever the technology. I hope I have covered most of the options, no doubt there are other possible technologies, both sensible and hare-brained.
None of the above address another major energy problem – transport by air, land and sea, and the associated world of commerce. Guess that’s for another day.