solar thermal the way to go for large-scale power generation?

[Fuchs66]

As far as the transport of energy goes anyone heard if there have been more thoughts about hydrogen production in hot countries using solar energy with the transport of the hydrogen as a hydride? Read a bit about it a few years back seemed an interesting and feasible concept.

 

[Crispy]

It's possible, but I'd need persuading that it's more efficient than HV cables.

 

[Fuchs66]

but with the distances involved surely the losses from HV cables would be massive, we're talking about the warmer regions of the world supplying us lot up north (and down at the other end too of course)

 

[kyser_soze]

Why bother going to all that time, expense and trouble when you can use local renewables like wind&wave somewhere like the UK?

 

[Fuchs66]

Why bother going to all that time, expense and trouble when you can use local renewables like wind&wave somewhere like the UK?

would of course depend upon the realistic outputs that could be expected from the various methods but IIRC the solar option with export to cooler climes was looking promising, this is some years back and I haven't heard much since.

 

[stdPikachu]

Why bother going to all that time, expense and trouble when you can use local renewables like wind&wave somewhere like the UK?

Ten to one the UK will use much more energy than it produces from renewable sources for several decades at least; a pan-continental grid at least gives us the option to purchase solar electricity from Africa or elsewhere, where they're likely to be able to produce much mroe electrcity then they can use (given the proper investment). It's a sensible long-term infrastructure thing more than a convenience thing.

P.S. Feasible, please!

 

[kyser_soze]

Hmm, I'm thinking more along the lines of energy security and still being reliant on overseas for power generation, but point taken...

 

[xenon]

...
P.S. Feasible, please!

Originally Posted by Crispy
No, not really (feaseable)

Crispy.

 

[free spirit]

we've been running a 2 gigawatt High Voltage DC interconnector from france to england since 1985, and a 160 mw HVDC connector since 1961. There's already a 700mw HV interconnector from morocco to spain (installed in 1997) and they're in the process of deveolping a high voltage mediterranean ring to connect all the countries round the med basin. Plus a 700mw sub sea interconnector between holland and norway.

plus there's an EU wide project to upgrade the high voltage grid between and within countries that seems to be progressing slowly but steadily.

I don't see that huge solar thermal farms in north africa sending power via High Voltage lines is the entire solution, but it's almost certainly going to be a major part of the solution IMO.

 

[WouldBe]

we've been running a 2 gigawatt High Voltage DC interconnector from france to england since 1985, and a 160 mw HVDC connector since 1961.

Any ideas how they convert the DC back to AC?

It's been confusing the fcuk out of me.

 

[free spirit]

Any ideas how they convert the DC back to AC?

It's been confusing the fcuk out of me.

rectifiers and invertors do some magic stuff to switch between ac and dc. I've got a vague idea how they do it, but it's a wee bit over my head. The wikipage on hvdc looks a pretty good overview actually, worth a read.

according to wiki, HVDC lines are capable of much lower losses than AC over long distances, 3% transmission loss over a 1000km is quoted. At that level of transmission loss it could well be viable to run HVDC cables the 2km or so from north africa to the UK direct (ie not via the main continental european grids).

there's apparently a 1700km 560 MW HVDC line in the Congo of all places (Inga-Shaba), which has been running since 1982, so a 2000km line's not much of an increase.

If largescale solar thermal really is 10% of the cost of solar PV, it could well work out cost effective to build a load of big solar thermal power stations somewhere in north africa. It does raise some concerns about it jsut being another land grab by us lot, and IMO you'd also need to make sure the country you base it in get's the power it needs too or you'd just be creating another reason for resentment against the west, but it looks technically possible.

 

[Crispy]

It's not like oil though, where the resource is finite, and there are only so many wells you can dig. If you want more power, just build more mirrors. Although this won't completely remove geopolitics from the equation, it does remove some of the particularly nasty aspects of the oil business.

 

[free spirit]

It's not like oil though, where the resource is finite, and there are only so many wells you can dig. If you want more power, just build more mirrors. Although this won't completely remove geopolitics from the equation, it does remove some of the particularly nasty aspects of the oil business.

yeah but if you can sell electricity at a premium via the HVDC line to the UK, rather than sell it locally for less money, capitalism being the way it is, you could well end up with huge solar thermal farms right next to villages that have no leccy - which would piss me off if I was living there.

I'm not really sure how the economics actually pan out, but I can forsee it being problematic if done in the usual cack handed way.

 

[crustychick]

Surely using solar thermal to generate electricity is really really inefficient. for the amount of electricity you'd get you'd need a huge area of collector I'd imagine... I'd love to be proved wrong but I don't think it's going to take off... unless they know something I don't (I'd be delighted to be proved wrong - I'm no physicist)

 

[kyser_soze]

Well it's working in Spain and Oz - did you check out the links on P1 of the thread?

 

[Crispy]

Depends what you're measuring with 'efficiency' - Mirrors are cheap, and suitable land is empty and otherwise worthless.

 

[crustychick]

Well it's working in Spain and Oz - did you check out the links on P1 of the thread?

no, I'm lazy I wanted to wade right in and spark a debate

seriously though.... for the amount of land you'd need to generate enough electricity for a similar size area. might work in Oz and Spain, perhaps some parts of Africa, but I think we'd be better off developing cheaper/thin-film PV technology or some kind of giant solar Stirling engine

 

[Crispy]

I think you should read the thread, c-chick

 

[two sheds]

Well wehey:


http://www.guardian.co.uk/environment/2007/dec/02/renewableenergy.solarpower

Europe is considering plans to spend more than £5bn on a string of giant solar power stations along the Mediterranean desert shores of northern Africa and the Middle East.

More than a hundred of the generators, each fitted with thousands of huge mirrors, would generate electricity to be transmitted by undersea cable to Europe and then distributed across the continent to European Union member nations, including Britain.


Billions of watts of power could be generated this way, enough to provide Europe with a sixth of its electricity needs and to allow it to make significant cuts in its carbon emissions. At the same time, the stations would be used as desalination plants to provide desert countries with desperately needed supplies of fresh water.

Looks like they're going for the tower system if it does go ahead. Quoting 10 eurocents/kWh over the next decade if the technology takes off, so about 15 US cents/kWh which is a fair bit more than the Ausra system. You'd think Middle Eastern countries would be interested - bit of investment now and they'd have solar power to take over from oil as it gets more expensive.

 

[WouldBe]

and fresh water.

 

[two sheds]

and fresh water.

Yus, for a nice cup of tea too.

 

[free spirit]

Looks like they're going for the tower system if it does go ahead. Quoting 10 eurocents/kWh over the next decade if the technology takes off, so about 15 US cents/kWh which is a fair bit more than the Ausra system. You'd think Middle Eastern countries would be interested - bit of investment now and they'd have solar power to take over from oil as it gets more expensive.

I wonder if that is the local price, or the price of power sold to europe including the costs of laying the cable etc. If it's an all in price to europe then it's probably not that unrealistic, and fossil fuel energy prices are heading that way anyway, and the solar price surely has the scope to drop significantly once they've got it all sussed and economies of scale kick in.

 

[free spirit]

I've done some digging, and a lot of reading, and decided the DESERTEC plan that two sheds article's about needs a thread of it's own <here>

cheers for the head up on that two sheds, looks very interesting, and I like the way it reaches the same conclusions we seemed to be reaching in this thread (only a fair bit more detailed and with a serious chance of actually happening).

it just occured to me that the photo accompanying that observer article is actually of a big PV array, thereby nicely demonstrating one of the problems highlighted in the report in terms of lack of public and media understanding of the differences between solar pv, contentrated solar thermal, and solar thermal for water heating.

 

[kyser_soze]

I wonder if that is the local price, or the price of power sold to europe including the costs of laying the cable etc. If it's an all in price to europe then it's probably not that unrealistic, and fossil fuel energy prices are heading that way anyway, and the solar price surely has the scope to drop significantly once they've got it all sussed and economies of scale kick in.

Do you know of any pricing models? It strikes me that solar of any description, as with other non-burning renewables will only ever be static or go down - the only ongoing costs are maintainance and transmission since the fuel is free...

it just occured to me that the photo accompanying that observer article is actually of a big PV array, thereby nicely demonstrating one of the problems highlighted in the report in terms of lack of public and media understanding of the differences between solar pv, contentrated solar thermal, and solar thermal for water heating.

I've given up expecting picture editors on newspapers to ever get something like that correct...

 

[two sheds]

I wonder if that is the local price, or the price of power sold to europe including the costs of laying the cable etc. If it's an all in price to europe then it's probably not that unrealistic, and fossil fuel energy prices are heading that way anyway, and the solar price surely has the scope to drop significantly once they've got it all sussed and economies of scale kick in.

Yep good point. And when comparing prices we should be comparing real costs, so renewables against (for example) coal with CO2 sequestration. This is still untried because it hasn't been done yet on a large scale, and won't half bump up fossil fuel costs. We are all going to have to pay the additional costs of 'cheap' power that bangs out thousands of tons of CO2 into the atmosphere.

Otherwise, it's like comparing raw costs of goods from a supermarket against Fair-Trade costs. It's society that picks up the extra supermarket costs of (for example) workers and suppliers also having to claim benefits when they are working rather than being paid a living wage.

 

[free spirit]

Do you know of any pricing models? It strikes me that solar of any description, as with other non-burning renewables will only ever be static or go down - the only ongoing costs are maintainance and transmission since the fuel is free...

from the desertec white book

I think that model's largely based upon experience with wind and solar PV - ie. based on a fairly standard model of how costs decrease with installed capacity.

I've given up expecting picture editors on newspapers to ever get something like that correct...

ay, think I might write to the picture editor to point out the mistake, maybe next time they'll get it right. It also strikes me that it kinda demonstrates whoever's doing the PR for the desrtec thing's not very good as they should surely have included a range of images with the press release.