Big EU imports of Sahara sun-power coming soon? The European Union might subsidise "interconnector" undersea power lines beneath the Mediterranean for the purpose of importing solar energy from the Sahara desert, according to reports. "I think some models starting in the next 5 years will bring some hundreds of megawatts to the European market," European Energy Commissioner …
"At the coast, use electricity and seawater to create hydrogen, liquefy it as per existing LNG technology from North Africa, ship it to the UK (European?) ports that already have LNG import technology (or again build some if not convenient) and ship it onward to large gas consumers such as gas-powered electricity generating stations which can readily be adapted to burn H2 as well as/instead of CH4"
Just to re-cap desertec's plan is to use the sun to heat a fluid (low pressure but *very* hot) so it can be stored or used to make steam (very hot and very high pressure) to drive existing tech steam turbines. Depending how much fluid you keep in the loop you either have a fast responding system or one with substantial storage running after sun down.
As for your idea about Hydrogen being like LNG storage you are *very* wrong. A heat leak on an LNG take will freeze water out of the air. A heat leak on a Hydrogen tank will give a pool of liquid Oxygen as it's 5 x colder than LNG. That's 111k Vs 20k. If that sounds harmless to you perhaps you should try it yourself. Hydrogen also has the ability to diffuse through most metal pipes (and it does even better with other materials) while making them prone to fracture (a process called Hydrogen embrittlement)
Producing Hydrogen for long term *storage* or long distance *transport* is almost *never* the answer. It has been commented upon before. Yes it *is* the cleanest burning fuel possible. It's other features (and there are a lot) make it a royal PITA in *every* other way.
Let's have a quick look.
Traditional nuclear: capital intensive, running costs greatly dependent on cost of money and long term waste storage costs, limited ability to follow daily demand cycle (for economic and technical reasons). Capital costs unproven (Flamanville not so bad, Olkiluoto not so good). Huge construction leadtimes due to technical and regulatory considerations.
Desertec-style: capital intensive, running costs greatly dependent on cost of money (but no long term storage costs), limited ability to follow daily demand cycle (cost of energy storage). Capital costs largely proven (HVDC and CSP both in use elsewhere, all this needs is to scale up, and ideally get some new storage to handly the daily cycle). Construction leadtimes probably no worse than nuclear, regulatory aspects probably simpler.
(sometimes a table is worth a thousand words, but...)
So, where are the big differences? If nuclear makes financial sense (and some folk think it does), there's no basic reason why Desertec doesn't too, in fact Desertec makes *more* sense because more of it is simpler.
I think there's a place for both in a lower carbon economy.
From an economic point of view there are at least 2 *big* differences.
Nuclear power stations start making electricity (or money depending on your POV) once complete. I think the French went to a *very* standardised set of designs and got this down to a fairly short period but the first build of their new design (which I think is what EDF are pitching to the UK) is still under construction. Their are some *very* big bits that can only be made by a few companies worldwide (if you go with a forged pressure vessel only 1 company has the hardware and the *certification* to do the work and *they* are Japanese. This was one of the prime elements of the planned UK govt loan to Forgemasters to buy a 15000 ton press )
OTOH Concentrated solar can be built in stages. I'm guessing that 1st power could be 6-12 months from contract signing. You can build out from there bootstrapping off the early revenue.
I *think* the French got it down to 18 months with their *previous* generation of reactors so not too big a difference there, but with the new generation, who knows?
The other big one is waste. No real problem for desertec as all the materials can be recycled but a *big* one for nuclear. Not the tech, but who *pays* for it. My *impression* (and I'd love to be corrected on this) is that nuclear operators think the host *government* should pick up the bill for this. If so this is *exactly* the sort of private profit/public cost deal UK banks seem to have been enjoying. Is a business plan that *depends* on HMG picking up the tab for the disposal for all this crap "sound"? I'm no expert so I'm not sure how well *quantified* these costs are but their scale *will* be in the £Bn. That's a pretty substantial "business risk" that had better be nailed down tight.
I have not mentioned the safety aspects which are less of a concern to financial people. However the new generation French reactor has hit trouble due to non compliant concrete and cracks in the structure (it's still under construction).
Note that concentrate solar is *not* entirely safe. Piping round superheated steam is dangerous (contrary to films superheated steam is *invisible* and the noise can be in the ultrasonic range, giving a plume of air that will flash fry anyone walking through it). Were a section of the array to be sealed it *could* build up enough pressure to shatter the glass tubes like hand grenades and Swiss cheesing the collectors (although burst disks could stop the damage). Depending on the salt selected the heat store would be quite hazardous due to temperature and chemical nastiness to the workforce. It's difficult to conceive of a set of faults which could cause site wide damage on the scale of say 3 mile island before some fairly simple safety devices kick in and dump the problem. Not something you want to make a habit of but no permanent damage done.
Basically *any* system that generates and store *lots* of energy should be treated with substantial respect
AC thanks JS19 for the two posts.
Supeheated steam may well be potentially dangerous; I would recommend treating it with considerable respect, but surely on the whole superheated steam engineering is well understood, and tried tested and proven, e.g. in decades worth of GW-scale power stations around the world, both fossil fired and otherwise. And in various other industries too.
Wrt hydrogen storage + shipment: both California and Iceland had proposals (and trials) where hydrogen formed a significant part of the energy distribution network (audience reminder: hydrogen is not an energy source in the same way as fossil fuels). BMW even made a "production" hydrogen car. Were all these ventures doomed to technological failure from the start, or were there other issues e.g. Iceland trial's reliance on well known green pioneer, er Shell?
"The other big problem is waste. No real problem for desertec as all the materials can be recycled but a *big* one for nuclear. Not the tech, but who *pays* for it. My *impression* (and I'd love to be corrected on this) is that nuclear operators think the host *government* should pick up the bill for this. If so this is *exactly* the sort of private profit/public cost deal UK banks seem to have been enjoying. Is a business plan that *depends* on HMG picking up the tab for the disposal for all this crap "sound"?"
Indeed. Nuclear power is only economically interesting if you're willing to fiddle the economics so the taxpayer guarantees the expensive bits. In a fair market, why should only nuclear get this privilege?
"Depending on the salt selected the heat store would be quite hazardous due to temperature and chemical nastiness to the workforce. "
But probably nothing that hasn't routinely been deployed in chemical factories around the UK and elsewhere (probably on a slightly smaller scale though).
"the new generation French reactor has hit trouble due to non compliant concrete and cracks in the structure (it's still under construction)."
Indeed. Olkiluoto and Flamanville mentioned earlier are two contrasting examples of the alleged same design (though the control system design at Olkiluoto is not yet approved so how they can be declared the same in anything other than outline is troubling). Flamanville in France is seemingly doing OK. Olkiluoto is a well documented disaster, including the concrete issues you mention and the control-system design issues and massive cost/timescale issues and...
"Wrt hydrogen storage + shipment: both California and Iceland had proposals (and trials) where hydrogen formed a significant part of the energy distribution network (audience reminder: hydrogen is not an energy source in the same way as fossil fuels). BMW even made a "production" hydrogen car. Were all these ventures doomed to technological failure from the start, or were there other issues e.g. Iceland trial's reliance on well known green pioneer, er Shell?"
Firstly Iceland is a state of 300k people. California is a state whose GDP would put it at *least* in the turnover of the top 20 world economies. Both are energy rich either by oil and wind or geothermal and hydroelectricity.
That's important because the issues around H2 are only *partly* technological. They can be solved on a (relatively) small scale. The problem is how much *money* you're prepared to invest to do so on a *large* scale.
I note the Iceland scheme was kick started by a Chemistry professor. Chemists *love* the simplicity of H2 combustion (barely 19 species to model H2/O2 combustion IIRC).
The California plans talks about a minimum of 50 filling stations but not *how* they make their Hydrogen. One of the US hydrogen reports indicates there is 1 million miles of natural gas pipeline versus 1200 miles of Hydrogen. This is not surprising. Room temp H2 piping is welded stainless steel. IE It's *very* expensive relative to normal gas piping. If you want to send as a liquid you're looking at "Vacuum jacketed" IE *concentric* welded stainless steel lines with a vacuum between. Liquifying it take 1/3 of the energy carried per unit mas of H2 your liquifying.
That suggests they will make H2 by catalytic processing of natural gas, a *highly* energy intensive process to produce the "clean" fuel. They will then take a shed load *more* energy either to compress it to a reasonable volume or liquify it.
My point is that Hydrogen has a *lot* of problems which make the idea of it as a "drop in" replacement for *any* fuel ridiculous.
Key point. Hydrogen is an *exceptionally* awkward fuel to make, transport and store due to its natural *physical* properties, which don't change unless you live somewhere like Pluto. It has *very* poor energy *density*. Ikg of gasoline gives c62Mj at roughly 1.4l. 1Kg of H2 gives c112Mj at c12.9l (*If* it's at -253c), but as you've spent 1/3 of that to liquify it in the first place. 20% more energy at only 820% more volume.
Desertec is attractive because it works *with* existing distribution networks, not against them. It uses pedestrian (but *very* large scale) technology to deliver a cost *effective* solution to the problem on a large scale.
If you ignore economics almost *any* scheme is viable on a small scale. However if it's not economic to begin with there is *no* incentive to grow and it will remain a dependent on (massive) state intervention.
You have to be clear *what* problem you are trying to solve. Call me an arrogant b*£$"$d but I think they have it wrong. Liquids fuels are easy to handle, store and move and allow vehicles to be "recharged" quickly. It is *possible* to make a steam powered car (and in the UK the steam powered speed record was recently broken), but why would you *want* to?
IMHO the ideal system would be a flywheel storage drive EV (no loss of capacity aging modes). However for the near term a system which uses the sun to generate electricity to charge a hybrid flywheel/fuel cell vehicle fueled by a renewable liquid fuel or near cryogen (LNG, LPG, Methanol perhaps). The concern is not so much CO2 in Earth's atmosphere, it's the *rising* level of CO2. Re-cycling that CO2 would slow it's growth and be relatively easy to do using *existing* infrastructure.
The ecology of some north-African desert hellwhole can only be improved by covering it over with black glass slabs. Ground temps go from 130-F to 110-F and snarky local vipers, Taliban wannabez & drop-dead scorpions can turn-off the AC !
Think I'm gonna gag at feckin-A euro-sensitive mud_hut lovers. Better to ram bitch-Gaia in the *zzwhole and get on with your AC_moderated business.
"The ecology of some north-African desert hellwhole can only be improved by covering it over with black glass slabs. Ground temps go from 130-F to 110-F and snarky local vipers, Taliban wannabez & drop-dead scorpions can turn-off the AC !
Think I'm gonna gag at feckin-A euro-sensitive mud_hut lovers. Better to ram bitch-Gaia in the *zzwhole and get on with your AC_moderated business."
Good evening Mr Cheney. So glad you could join us. Thank you for that *very* succinct description of recent American policy on this matter.
The Register 
Biting the hand that feeds IT
Copyright. All rights reserved © 1998–2024
