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How Orkney Leads the Way For Sustainable Energy (theguardian.com)
An anonymous reader shares a report: It seems the stuff of fantasy. Giant ships sail the seas burning fuel that has been extracted from water using energy provided by the winds, waves and tides. A dramatic but implausible notion, surely. Yet this grand green vision could soon be realised thanks to a remarkable technological transformation that is now under way in Orkney. Perched 10 miles beyond the northern edge of the British mainland, this archipelago of around 20 populated islands -- as well as a smattering of uninhabited reefs and islets -- has become the centre of a revolution in the way electricity is generated.
Orkney was once utterly dependent on power that was produced by burning coal and gas on the Scottish mainland and then transmitted through an undersea cable. Today the islands are so festooned with wind turbines, they cannot find enough uses for the emission-free power they create on their own. Community-owned wind turbines generate power for local villages; islanders drive nonpolluting cars that run on electricity; devices that can turn the energy of the waves and the tides into electricity are being tested in the islands' waters and seabed; and -- in the near future -- car and passenger ferries here will be fuelled not by diesel but by hydrogen, created from water that has been electrolysed using power from Orkney's wind, wave and tide generators.
Orkney was once utterly dependent on power that was produced by burning coal and gas on the Scottish mainland and then transmitted through an undersea cable. Today the islands are so festooned with wind turbines, they cannot find enough uses for the emission-free power they create on their own. Community-owned wind turbines generate power for local villages; islanders drive nonpolluting cars that run on electricity; devices that can turn the energy of the waves and the tides into electricity are being tested in the islands' waters and seabed; and -- in the near future -- car and passenger ferries here will be fuelled not by diesel but by hydrogen, created from water that has been electrolysed using power from Orkney's wind, wave and tide generators.
Hydrogen is a way of storing energy the same as a battery. Today batteries are better in every possible way except possibly air travel. Hydrogen is dangerous, hard to store and hard to transport. Again, except possibly for air travel, hydrogen is either expensive or less efficient to turn back into mechanical energy.
True, but the reason hydrogen storage is still interesting is that the storage capacity you can achieve with hydrogen based completely dwarfs anything you can achieve with batteries, hydro storage or practically anything else at the moment. The round trip efficiency is currently between 30-40 %, it can realistically be increased to 50% in the near future. If you recover the stored energy by burning the hydrogen in in a combined cycle gas power plant the efficiencies is as high as 60%.
Hydrogen wins when you need to store store truly massively amounts of excess energy
Actually, it is usually not the best solution. Pumped storage and compressed air have better efficiency and need less capital investment. Vanadium-redox will give much better efficiency, and can scale with just a bigger tank.
If hydrogen made sense for grid storage, profit seeking companies would be doing it. They aren't.
Hydrogen storage only makes sense when weight and/or power density are more important than efficiency.
Are you familiar with the Aquion Saltwater battery? http://aquionenergy.com/techno...
I haven't really dug into it, but it sounds like the technology is at the very least a *lot* cleaner than the existing options, and possibly no more toxic than the ambient environment.
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they cannot find enough uses for the emission-free power they create
How about using all their excess electricity to make the next generation of wind turbines to replace the ones they bought from an industrialised country?
Generating their own electricity is nice, but it doesn't make them self-sufficient. They are completely dependent on places with mines, steel plants, manufacturing and development to send them the equipment to generate electricity and to maintain it. If they wanted properly sustainable energy, they would have produce the wind turbines on their islands.
But that would require a fully industrial society which their small population could not support.
politicians are like babies' nappies: they should both be changed regularly and for the same reasons
Correct, but also missing the effect of geographic distribution. Turns out that when you have enough capacity over a wide enough area the capacity factor of the fleet as a whole goes up a lot. Throw in some battery backup to smooth output and handle peaks and you have a capacity factor close to coal or nuclear.
Obviously you still want a mix of energy sources, and long distance transmission lines, but 4x overbuild for capacity is likely excessive.
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Thing is a nice dyke across the Pentland Firth could extract enough tidal energy to power the whole of Scotland, and be utterly predictable as to it's output. Just stick in some additional pumped storage (plenty of capacity for that in Scotland) and we would be sorted. Now sure that dyke is going to cost, but they want 30 billion GBP for a nuclear power station with less capacity.