I’ve been away briefly this week, to an extremely cold and windy Suffolk coast. Not the kind of break one comes back from tanned – other than with wind-burn – or with skiing fractures, but remembering there is a world beyond academia seems important to me, to help me put the world in a bit of perspective. Nevertheless, it has to be said the weather was disgusting even by British seaside standards. Struggling against the wind, trying to make sure my deplorable woolly hat didn’t disappear into the far distance (the wind was off the sea, a fierce easterly, so at least the hat wasn’t going to get tossed into the sea), I was disappointed to find my mind still didn’t turn off from physics.
The sea was in a fury of white foam, layer upon layer of froth as the waves beat at the steep shingle bank we stood upon. The foam was also constantly blowing up and onto the beach and onto our clothes. Why was the foam so long-lived? Irritating to find myself trying to answer that question; I was NOT there to think about colloids! I do not believe the sea is now so jammed full of detergents (as sometimes one sees when a river gets frothy due to local pollution) that the foam is permanently stabilised by Fairy Liquid and its cousins. Whether the fury of the waves was sufficient, or whether there are saccharides or other molecules excreted by marine organisms contributing to a lowering of the surface tension, I don’t know. And to be honest, when on holiday, I DON’T WANT TO KNOW.
Waves is the subject I’ve been teaching to 400 eager (and not so eager) 1st years in Cambridge for the past few years; I’ve also taught it previously (in more advanced form) to second years, and I have therefore had professional occasion to consider the nature of water waves, and seek out examples of how they behave. Shallow water waves and deep water waves have different dispersion relationships and hence behaviour, but I’m quite sure neither representation would have been adequate to describe the turbulent water that seethed at my feet. When I first started lecturing this material some years ago now, I came across the idea (and traditional images) of a tsunami, without having any idea of what such a thing was. I thought it was some obscure Japanese folklore. Of course, since 2004 (and again in 2011), no one could possibly have any illusions about the importance of this phenomenon, even though it still doesn’t feature explicitly in my course.
There wasn’t a proper sandy beach, no shells or crabs, I saw only the remains of cuttlefish (calcium-rich aragonite, if you’re interested, and a useful and controllable buoyancy aid for the marine creature as long as it doesn’t go too deep, where apparently the gas-filled chambers of the bone implode under the pressure). The shore mainly consisted of shingle and marram grass, but there was sand a-plenty, much of it being blown into my mouth or smothering the esplanade: Lewis Carroll’s seven maids came to mind, although there was only a bulldozer which might have been attempting the same task. And where there was an accidental layer of sand covering, it had interesting ripples. Again my physicist’s mind went into annoying overdrive: what determined the periodicity of the ripples? No doubt, as with any similar instability, there is an optimum/fastest growing wavelength set by a balance of two factors, probably involving the distance the sandgrains have to migrate to build up the peaks and something to do with windspeed and how the peaks affect the local forces on the grains due to the wind. I reiterate, I was on holiday and I DON’T WANT TO HAVE TO THINK ABOUT THIS….I want to switch that part of my brain off. NB this means I’m not looking for a detailed analysis of the problem in any response.
Of course, battling the power of the wind could hardly fail to remind me of the possibility of wind as an alternative energy source, and towering over Kessingland where we were staying were two large wind turbines rotating at speed. The figure I had just read in the book (Project Sunshine) co-authored by my friend and long-term collaborator Tony Ryan flashed into my mind. This book, an impressive, sweeping overview of our energy problems past, present and of course future, claims the outermost tips of the blades whizz round at 200mph. Do they? I refused to try to check that mental calculation out; I wanted to head for the pub. There weren’t any offshore installations that I could see, despite what felt like a good opportunity to extract some energy from the ferocious wind, but I have been to this part of the coast when all is still and, as both Tony’s book and the earlier Sustainable Energy without the Hot Air, by my Cavendish colleague David Mackay, now CSA at the Department of Energy and Climate Change make plain, storing energy from wind turbines and other sustainable energy sources is a major, unsolved challenge.
I had come to this part of the Suffolk coast with two aims. The first I had failed at badly; I hadn’t switched off from the day-job as well as I’d hoped, as the anecdotes above will make plain. My other aim had been to come to make my peace with this particular part of the sea. Some years ago I’d visited Southwold at a time of turbulence and upset in aspects of both my professional and personal life. Whereas, throughout my life, I have found watching agitated and tumbling water to be a powerful source of peace, grounding and wonder, on that occasion I had found it simply moved me to tears with no accrued benefit. It was almost as upsetting then to find that wave-watching no longer restored my spirits as to suffer from the underlying distress itself.
To return to the same part of the coast and feel, once more, the joy derived from the unceasing and unpredictable motion of inky, churned-up water, was the true benefit of the break. It was good too to remember just how far I have been able to recover from what had seemed to be an encounter with an unassailable brick wall. If that recovery hadn’t occurred I could never have started this blog; so this seems like a good moment to remind the reader of a truth I have discussed before, that no one, however outwardly successful, is unlikely not to have been kicked in the teeth on more than one occasion. Equally they will have found some mechanism to use that to their advantage, to find a way round the immovable object blocking the way or at least to bury the bad memories so that they no longer impede daily life.
This same stretch of coast, a bit further up near Great Yarmouth, was home to that Dickensian family of Peggotty who lived in a boat on the shore – I was reminded of this as we walked past over-wintering boats dragged high up on the shingle. As it happens, I’m just reading Claire Tomalin’s biography of Charles Dickens. It is not irrelevant to the previous paragraph that he suffered in his youth, notably from his period in a blacking factory, and yet, as she puts it
‘What is most remarkable is the strength of the image he had of himself ,his belief in his own capacities and potential, justified by everything that came after, but quite uncertain then.’
Additionally, the vulnerability he felt in the factory found its way into many of the children he characterised in his novels and provided fertile experience for him. However, few of us are likely to have quite that degree of self-belief and robustness Tomalin attributes to Dickens, particularly as at the time under consideration he was around 13 years of age. Nevertheless, it is healthy to remember that today’s catastrophe can (although it most certainly won’t necessarily do so) blend seamlessly into much more happy circumstances, with the accompanying wisdom of experience and accrued toughness. A small nugget to try to hold onto if your world appears to be crashing down around your ears.
The only solution I could ever find to the yet unsolved challenge of storing energy from wind turbines and other sustainable energy sources is to go they other way, not store it at all, but use it all to supply a demand as its produced.
For that to be achievable you’d have to contemplate producing energy for supranational consumption on a very large area scale. Over and beyond enormous geographical boundaries that determine distinct and powerful fluctuations in weather, the odds are that when say, there is no wind to power turbines in some areas, it might be pretty gusty elsewhere. In the case no winds at all and as a notable supranational example, there have already been plans to sell electricity produced from a solar thermal plant in north African Morocco to Europe.
Some countries do sell electricity to each other and though I am not advocating running an electrical cable around the whole world, adjacent national territories ought to have a shared electrical grid so as to make 100% use of renewable energy as it is produced, without the need to store any of it.
http://worldcrunch.com/business-finance/solar-energy-for-europe-direct-from-the-moroccan-desert/dii-desertec-morocco-solar-renewable/c2s10021/#.UVRC4xc4vTo
Flow batteries are one solution to storing electricity from intermittent sources (like wind). The University of New South Wales has been working on this for many years and have shown some very impressive results.
You can find further information in this Wikipedia article:
http://en.wikipedia.org/wiki/Vanadium_redox_battery
There are also people working on other redox reactions that do not involve vanadium.
Through Twitter I am informed by @DrAliceRoberts that it’s the proteins from seaweed that give the foam its longevity by acting as surfactants. That makes sense, although the beach in question was apparently devoid of seaweed. For Alice as a biologist, the beach is also a place of scientific distraction. She says ‘A walk on a beach is equally dangerous for a biologist with fish skulls, bird wings and goose barnacles on the tide line.‘
I forgot to say that what we really need is computer technology to supranationally regulate non renewable energy production relative to the amount of renewable energy being produced at any one time.
Because of the inherent unreliability of renewable sources of energy that are influenced by the prevailing weather, even if the energy produced by renewables was by far the vast majority, it would still be impossible to guarantee a constant supply at the same rate. To try to supply a constant rate for a total energy demand would mean over installing the mechanisms for renewable energy production and even then, who could thoughtfully promise that rare freak weather conditions might not still cause a power shortage?
If humanity does ever get to the point where renewable energy is the majority means of energy production then to be able to fall back on non renewables in lean renewable energy times would have a negligible effect on global warming and healthy pollution levels.
After all, non renewable energy sources might not be batteries but still, they are stored energy as well.
Isn’t the answer to store the energy in chemical bonds, like in the electrolysis of water to hydrogen and oxygen? Such a fuel cell can run either way (to make storable gas or electrons) and surely the questionable level of efficiency is better than not capturing the free energy at all
@JJBP Electrolysis of water into hydrogen and oxygen sounds so tempting, especially in regions not plagued by much cloud cover. Deserts beside expanses of water seem an appropriate investment. You could use the Sun alone to power the evaporation of salt water in giant solar stills from which you’d get sea salt to sell as a product and quite a pure source of fresh water. You’d perform the electrolysis on the fresh water or use it to create commercial green areas for food production in otherwise wasted lands.
If we could ever get a country like China to backwards engineer the hydrogen engine and have them produce it in mass for vehicles or energy production they’d be well ahead of everyone.