A party member recently wrote to me asking about the potential of tidal power. Here’s my reply (slightly edited).
A lot of big questions! But I’ll do my best.
In my new Energy Policy Booklet (p8) I say that tidal power is worth a look. I put that in mainly in deference to the views of other party members, but I’m not optimistic. I didn’t include any reference to wave power, but I don’t think that wave power devices would survive long enough in the harsh offshore environment to recover the investment — and as you say, they’re intermittent.
Tidal ideas like the Severn Barrage are a little more serious. But as Christopher Booker points out, for a fraction of the cost you could build three nuclear reactors to deliver equivalent power, but in a baseload format, reliably and continuously. The nuclear solution would also have a far smaller geographical foot-print. You mention pumped storage, but that requires particular topology that’s probably not available in the Severn estuary (hills with lakes or dams). In any case, pumped storage involves significant power losses and inefficiency.
Moreover the Severn estuary would probably be ruled out (ironically!) for environmental reasons. It would destroy a huge and important wet-land habitat used by many species. Also major dam projects of this kind lead to all sorts of unintended consequences. Water losses through evaporation, silting-up behind the dam. End of the Severn bore.
For my own part, I’m focussing on what I see as the key technologies for power generation: gas, coal and nuclear. If you listen to the BBC, you’ll assume that coal has gone away. But there are over 1200 new coal-fired power stations in the pipeline globally — including 20+ in Germany, believe it or not! The Greens (and the European Commission) need to get it into their heads that global CO2 emissions will rise for the foreseeable future no matter what we do, no matter what hair shirts we wear, no matter how much we restrict and damage our economy in the name of Climate Change. The message to the Greens and the EC is “Get used to it!”.
But I am of course open to the idea of renewable technologies if they’re economically viable. For example: I’ve inveighed against solar PV, which is unpredictable and intermittent (like wind) and hopelessly uneconomic. But I’m perfectly prepared to accept that in coming years there may be dramatic enhancements in solar PV efficiency, which would make it a viable addition to the mix. Just because we’re against it today, that doesn’t mean we’ll be against it in ten years’ time, if the numbers stack up.
Interestingly, the oceans may be a source not of energy but of raw materials. There are huge amounts of (inter alia) gold and uranium in sea water. Currently it’s too diffuse to extract, but emerging technologies may enable us to mine the sea for metals. We should remember that when the Greens tell us we’re just about to run out of everything!
There’s more in the sea — or rather in the sea bed. Natural gas is found in methane hydrates, typically on the edge of the continental shelf. On some estimates there’s more energy equivalent in methane hydrates than in all other known fossil fuel deposits. So we have shale gas for a hundred years — perhaps several hundred years — and with the methane hydrates, perhaps for a thousand years.
There is, of course, no earthly point in speculating about how we’ll generate energy in a thousand years’ time. We’ll be using technologies which today we can’t imagine. Maybe nuclear fusion will have come and gone. But I am hugely reassured to know that we have natural gas for the foreseeable future.