Solar Panels - change of views on this NG?

[The Other Mike]

Far better to dump waste in it and then harvest the biogas :)

[David WE Roberts]

Thanks for all the responses.

So to sum up what I think I've heard:

The current subsidy is aimed at kick starting the installation of PV arrays on domestic roofs and does not reflect real costs of electricity generation.

The cost of materials and installation is expected to fall over the years, and the level of subsidy for new installations is expected to fall to reflect this.

The trick is to catch the point where you get the most subsidy for the least installation cost (which could be now).

[I so far haven't seen any mention of warranty, insurance backed or otherwise.]

To digress a little:

The underlying issue with this type of "green" energy generation is that it feeds directly into the grid but cannot be guaranteed to be available on demand - so you still have to size your main generating plant to cope with the overcast freezing days in the middle of winter when there is no wind. So you don't save anything on capital outlay on mainstream generating plant, just ease peak load on sunny windy days.

If there was a system where you stored all the energy you generated so it was available when the power source was not available then this would make a real impact on the overall power network. It would also make it much easier to live "off grid".

If you got the storage to work so well that individual homes could buffer the national grid by storing energy overnight and feeding back in during the day then the whole network could potentially be more efficient, need less spare capacity, and fully utilise alternative energy sources.

The storage batteries for electric cars have been suggested as the basis for such a system, but a lot of extra infrastructure seems to be required, plus much more efficient storage batteries.

So perhaps this is the first stage; get the collection infrastructure up and running and hope that the storage technology catches up in time.

Certainly we need to do something apart from paying more money and fighting more wars to try and secure a future supply of petrochemicals.

Despite the recent events in Japan, nuclear energy does seem to be a more economical source than a distributed solar array with massive batteries. We shall see.

Cheers

Dave R

[The Other Mike]

Costing the Earth on Radio 4 last week was devoted to the "solar gold rush"

Some wild and unsubstantiated claims about costs of equipment falling "rapidly" and "faster than any other generation method"

[The Natural Philosopher]

so far so good.

yes, but at the very best, you would lose 10% in turnround (lithiumn barreries) efficiencies, and what happens when your storage gets full? or empty?

Nope. the grid still has to be sized for PEAK flows, and the generators still have to be sized for PEAK flows.

It better with storage, but its still nowhere as ood as good old fashioned power stations.

and the home, is not where most electricity is used...

Plus more lithium than exists in the world for the batteries,.

No, the first step its to accept the fact the renewable energy by reason of the second law of thermodynaics is almost completely useless, and start thinking again.

Build more nukes then.Safest most reliable power generation there is.

Of course, thast why they are making all the fuss over fuku. they think there's another couple of tears of ripoff subsidies if they play their cards right.

[The Natural Philosopher]

well since its currently about 40p a unit, that wouldnt be hard.

It could fall 6p a unit easily.

Nuclear cant fall 6p a unit, because it only costs 6p a unit,!

Typical greenspin

[The Other Mike]

panels, not the outrageous level of subsidy that we fund from UK plc to enable it to become 'economic' for someone to install them.

Panels have dropped in price over many years but they have approached a plateau after Chinese got into the business, I can't see the production and retail cost of current technology panels dropping significantly regardless of increases in demand and production. You get a larger impact on prices with currency fluctuations, energy costs an knee jerk reaction from governments to large schemes than you do with what will only ever be marginal improvements in production processes especially when virtually all production facilities, even offshore ones are engineered by a very limited number of players.

[The Natural Philosopher]

You only need look at the price of LCD panels per square meter to have an idea of the limits of silicon and other style fab plants.

About 8 years ago I was involved in financial analysis of LCD fab..no fab plant had at that time even paid for its construction, let alone produced any returns, and LCDs are produced in huge quantities.

Remember when a windpower or PV company talks about capital cost per KW, they mean capital cost of the bare unit, of PEAK CAPACITY, not average capacity, not installed cost, nor maintenance, nor connection, nor balancing costs, amortised over a relatively short lifespan.

That's why you get the headline 'really competitive costs' AND the need for massive subsidies.

[Man at B&Q]

Has anyone made "petrol" from the H and C that occur in the air and sea? If so how efficient is the process? Is it feasible/worthwhile to do it with cheap nuclear power to produce a readily stored and transportable fuel for vehicles? Could it be done with wind and other "renewable" sources to buffer the variability in supply?

MBQ

[The Natural Philosopher]

If so how efficient is the process?

about 0.1%, and it takes 5 million years :-)

Seriously its doable, but the easiest synthesis these days is typically rape crop-> biodiesel. Or IIRC corn->ethanol Those are about 0.1% - 1% efficient and don't take 5 million years :-)

Direct synthesis is possible, but its pretty inefficient. Even more so if couled to an intermittent power source.

Is it feasible/worthwhile to

Its feasible, but not yet worthwhile.

No. Not reaistically.

Any industrial plant needs to run at capacity to generate a payback. If the power fluctuates, its not doing that, and it becomes inefficient in terms of materials and capital cost, and usually cycle efficiency as well.

The problem of intermittency cannot be solved except with more intermittent plant. Two wrongs make an even worse wrong.

[John Rumm]

There is also a place in the US that makes ethanol from waste wood, which seemed quite interesting...

[The Natural Philosopher]

methanol more likely = 'wood alcohol' If you go back to the re industrial age, lots of plant materials used as chemical feedstocks. Turpentine, creosote..methanol..all wood products.

Cotton is a great cellulose feedstock.

Ethanol form starches,

The the coal industry..coal tar, coal gas, and lots of phenolics like IIRC bakelite.

Then the oil age - plastics and other polymers, like epoxies

Its all POSSIBLE, the issues are all about costs and energy efficiencies.

[Steve Firth]

"Man at B&Q" wrote: [snip]

Yes, every single oil company that operates a refinery. Every drop of oil came from carbon and hydrogen present in atmospheric gases and water.

As efficient as it can be made. Wasted energy = wasted profit.

Not really. Used in the manner you describe oil products cease to be fuel and become an energy transport medium.

It would be better to grow Cyanobacteria using fusion power (from the sun) than to use other energy sources on earth. More efficient and reserves nuclear etc for applications where it is needed.

As above.

[Man at B&Q]

Yes, but I object to using potential crop growing land in 3rd world countries to feed the 1st worlds thirst for fuel.

MBQ

[Alan Braggins]

Ethanol is quite likely, the Americans add it to petrol (or gasoline):

most of that comes from corn syrup, but you can make it from wood: I know you can run engines on methanol too.)

[The Natural Philosopher]

I am pretty peeved about the fact that due to German government edicts, the fields around me can command a higher price for their rapeseed oil for biodiesel, than they can for either human ingested oil, or cattle fodder.

But then, post Labour, I suppose we ARE a 3rd world country.

[The Natural Philosopher]

Bloody good fuel, if a tad dangerous.

More than one racing driver burnt to death in a methanol fire he simply didn't know he had..the flames are almost invisible.

Having used it as model aircraft fuel, I can attest to that. Until the paint starts blistering or your hand gets burnt, you dont know its on fire.

[Tim Streater]

There isn't a huge amount of H in the air, or C in either. You'd have to "process" quite substantial quantities of either to get enough C. You could split water up to make hydrogen, but as usual you're screwed by the low energy density.

[Andy Champ]

Hydrogen is the best bet. But as Tim says it needs big tanks, even when fed to fuel cells not IC engines.

Andy

[John Rumm]

The smoke from the chip fat mixed in with it sometimes helps (assuming you use real caster and not synthetic that is)

[Alan Braggins]

Yes. Not efficient enough to be economically viable at present, I believe.