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[Dishevelled Den]

I'm not a mechanical or electrical engineer, so perhaps I'm talking absolute rubbish. 

I don't think that the technological advances over time that Lizzie Zoom is talking about can really be expected with wind or solar power.  The examples she quotes tend to be development from new discoveries or inventions.  On the other hand, wind and solar power are not new, and are already well advanced in development.  There are mathematical, physical and engineering constraints on how much further they can actually be developed.

There is a (somewhat informally defined) law of diminishing returns, and I would imagine that as far as mechanical generation of electricity from wind power is concerned, this is already applicable.  Solar energy is always going to be limited by the amount of light energy reaching the light sensitive material, as well as the conversion rate of that energy.  We will no doubt get more efficient conversion media, but we can't increase the amount of energy available over a given area.  (OK - we can use parabolic mirrors to concentrate the light, but the cost of manufacturing and controlling them - they have to be moved continuously - would be prohibitive.)

We do have some way to go with tidal and wave power, although tidal seems to upset the environmentalists.  And wave power hasn't actually been very successful so far, although I'm sure there's room for the technology to improve.

I tend to think we're stuck with nuclear, but if everybody goes down that route, we're going to run out of uranium before we run out of oil.  And the complexity of a nuclear power station means that they take forever to build, cost an unreasonable amount, and then cost even more to maintain.  Not mentioning, even, the decommissioning problem.

We're doomed, we're all doomed...

The only hope is nuclear fusion, and we're not even near to making that work.

Not absolute rubbish Jereboam, relative rubbish!   Only joking, there's a lot of sense in what you say (except that a parabolic mirror needs to cover the same area to collect the rays so only saves on area of pv convertor).

There are developments that can be made though with all these types of sporadic sources of energy, and that is in storage.  If we have sufficient (and that can usually be achieved by scale) total energy available (albeit random), we can store excess for use in quiet times. This is what Eigg did with their massive 24hr UPS).  On a larger scale this is done by pumping water up hills into reservoirs and then reversing it later with hydro-electric generation (called pumped storage hydroelectricity).

Cheap and high-density electric storage is likely to unlock a whole raft of benefits for society, not least in electric vehicles.  As with all large stores of energy, there will be nasty accidents and safety will be one of the determining factors in its acceptance.

On a larger scale this is done by pumping water up hills into reservoirs and then reversing it later with hydro-electric generation (called pumped storage hydroelectricity)

I think there's a plant in Wales that does just that, but are there sufficient sites - having suitable topography - on a national basis to make this type of storage a commercial possibility?

[jereboam]

I'm not a mechanical or electrical engineer, so perhaps I'm talking absolute rubbish. 

I don't think that the technological advances over time that Lizzie Zoom is talking about can really be expected with wind or solar power.  The examples she quotes tend to be development from new discoveries or inventions.  On the other hand, wind and solar power are not new, and are already well advanced in development.  There are mathematical, physical and engineering constraints on how much further they can actually be developed.

There is a (somewhat informally defined) law of diminishing returns, and I would imagine that as far as mechanical generation of electricity from wind power is concerned, this is already applicable.  Solar energy is always going to be limited by the amount of light energy reaching the light sensitive material, as well as the conversion rate of that energy.  We will no doubt get more efficient conversion media, but we can't increase the amount of energy available over a given area.  (OK - we can use parabolic mirrors to concentrate the light, but the cost of manufacturing and controlling them - they have to be moved continuously - would be prohibitive.)

We do have some way to go with tidal and wave power, although tidal seems to upset the environmentalists.  And wave power hasn't actually been very successful so far, although I'm sure there's room for the technology to improve.

I tend to think we're stuck with nuclear, but if everybody goes down that route, we're going to run out of uranium before we run out of oil.  And the complexity of a nuclear power station means that they take forever to build, cost an unreasonable amount, and then cost even more to maintain.  Not mentioning, even, the decommissioning problem.

We're doomed, we're all doomed...

The only hope is nuclear fusion, and we're not even near to making that work.

I understand and agree with what you are getting at Jereboam, but how can you say these are already well developed when no of us know what discoveries will be made that will make current progress seem positively archaic.  My earlier post was also touching on how man initialy thinks he has the answers then technological and scientific advancements produce staggering possibilities that cannot be predicted in the contempary environment.

Like with all technological advancements we have seen nothing yet in terms of wind and solar power development.   The only way you can say for sure what we have now is to live and have a 22nd century mind with all the knowledge by then accumulated.  Of course none of us have that yet.  We can only aim for that time, making mistakes all the way whilst we learn

I'm afraid I don't agree with you.  There really are limits on how far you can go to improve the efficiency of a wind powered generator.  The speed of technological advance we see today is vastly greater than in the days of steam, or internal combustion, engines.  They took a long time to increase their efficiency, and as that time extended, the rate of improvement fell as it always does.  Wind turbines have developed significantly faster, and the scope for efficiency improvement is very limited.  A new technology is needed - maybe Sir James Dyson could think of a way of turning unidirectional wind gusts into rotational motion and power a generator that way.  But wind turbines are rapidly approaching their efficiency limit.  And much the same argument applies to solar, although materials development may surprise us all.

[jereboam]

I'm not a mechanical or electrical engineer, so perhaps I'm talking absolute rubbish. 

I don't think that the technological advances over time that Lizzie Zoom is talking about can really be expected with wind or solar power.  The examples she quotes tend to be development from new discoveries or inventions.  On the other hand, wind and solar power are not new, and are already well advanced in development.  There are mathematical, physical and engineering constraints on how much further they can actually be developed.

There is a (somewhat informally defined) law of diminishing returns, and I would imagine that as far as mechanical generation of electricity from wind power is concerned, this is already applicable.  Solar energy is always going to be limited by the amount of light energy reaching the light sensitive material, as well as the conversion rate of that energy.  We will no doubt get more efficient conversion media, but we can't increase the amount of energy available over a given area.  (OK - we can use parabolic mirrors to concentrate the light, but the cost of manufacturing and controlling them - they have to be moved continuously - would be prohibitive.)

We do have some way to go with tidal and wave power, although tidal seems to upset the environmentalists.  And wave power hasn't actually been very successful so far, although I'm sure there's room for the technology to improve.

I tend to think we're stuck with nuclear, but if everybody goes down that route, we're going to run out of uranium before we run out of oil.  And the complexity of a nuclear power station means that they take forever to build, cost an unreasonable amount, and then cost even more to maintain.  Not mentioning, even, the decommissioning problem.

We're doomed, we're all doomed...

The only hope is nuclear fusion, and we're not even near to making that work.

Not absolute rubbish Jereboam, relative rubbish!   Only joking, there's a lot of sense in what you say (except that a parabolic mirror needs to cover the same area to collect the rays so only saves on area of pv convertor).

There are developments that can be made though with all these types of sporadic sources of energy, and that is in storage.  If we have sufficient (and that can usually be achieved by scale) total energy available (albeit random), we can store excess for use in quiet times. This is what Eigg did with their massive 24hr UPS).  On a larger scale this is done by pumping water up hills into reservoirs and then reversing it later with hydro-electric generation (called pumped storage hydroelectricity).

Cheap and high-density electric storage is likely to unlock a whole raft of benefits for society, not least in electric vehicles.  As with all large stores of energy, there will be nasty accidents and safety will be one of the determining factors in its acceptance.

Strangely enough, I was going to mention what you call "pumped storage hydroelectricity", but got interrupted and had to finish.  This is a very old idea, but a very good one.  It's never going to be a cheap solution, and I expect the efficiency of re-conversion will not be all that high, but it complements wind and solar electricity generation perfectly. 

There are drawbacks: suitable sites may not be adjacent to wind- or solar-suitable sites, and the power losses involved in taking the electricity to a suitable site may make it uneconomic.  I can't imagine there will be suitabe desert sites, for example, and that may be the best place for solar farms.

Its all very complicated.

[Chris_H]

I'm not a mechanical or electrical engineer, so perhaps I'm talking absolute rubbish. 

I don't think that the technological advances over time that Lizzie Zoom is talking about can really be expected with wind or solar power.  The examples she quotes tend to be development from new discoveries or inventions.  On the other hand, wind and solar power are not new, and are already well advanced in development.  There are mathematical, physical and engineering constraints on how much further they can actually be developed.

There is a (somewhat informally defined) law of diminishing returns, and I would imagine that as far as mechanical generation of electricity from wind power is concerned, this is already applicable.  Solar energy is always going to be limited by the amount of light energy reaching the light sensitive material, as well as the conversion rate of that energy.  We will no doubt get more efficient conversion media, but we can't increase the amount of energy available over a given area.  (OK - we can use parabolic mirrors to concentrate the light, but the cost of manufacturing and controlling them - they have to be moved continuously - would be prohibitive.)

We do have some way to go with tidal and wave power, although tidal seems to upset the environmentalists.  And wave power hasn't actually been very successful so far, although I'm sure there's room for the technology to improve.

I tend to think we're stuck with nuclear, but if everybody goes down that route, we're going to run out of uranium before we run out of oil.  And the complexity of a nuclear power station means that they take forever to build, cost an unreasonable amount, and then cost even more to maintain.  Not mentioning, even, the decommissioning problem.

We're doomed, we're all doomed...

The only hope is nuclear fusion, and we're not even near to making that work.

Not absolute rubbish Jereboam, relative rubbish!   Only joking, there's a lot of sense in what you say (except that a parabolic mirror needs to cover the same area to collect the rays so only saves on area of pv convertor).

There are developments that can be made though with all these types of sporadic sources of energy, and that is in storage.  If we have sufficient (and that can usually be achieved by scale) total energy available (albeit random), we can store excess for use in quiet times. This is what Eigg did with their massive 24hr UPS).  On a larger scale this is done by pumping water up hills into reservoirs and then reversing it later with hydro-electric generation (called pumped storage hydroelectricity).

Cheap and high-density electric storage is likely to unlock a whole raft of benefits for society, not least in electric vehicles.  As with all large stores of energy, there will be nasty accidents and safety will be one of the determining factors in its acceptance.

Strangely enough, I was going to mention what you call "pumped storage hydroelectricity", but got interrupted and had to finish.  This is a very old idea, but a very good one.  It's never going to be a cheap solution, and I expect the efficiency of re-conversion will not be all that high, but it complements wind and solar electricity generation perfectly. 

There are drawbacks: suitable sites may not be adjacent to wind- or solar-suitable sites, and the power losses involved in taking the electricity to a suitable site may make it uneconomic.  I can't imagine there will be suitabe desert sites, for example, and that may be the best place for solar farms.

Its all very complicated.

Ahh Bless!!
There are other ways of doing it.  Tower bridge uses weights and there's no real reason why a bladder under a mountain should not be pumped-up with liquid to raise it like a car jack.  When you need electricity, you let the liquid flow through turbines and Bob's your proverbial.

All these methods involve losses and your point about distance between variable sources and a storage scheme are real.  With electricity, the 'easy' fix is to step up the voltage for transmission - hence the 132kV grid.