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PostPosted: May 02, 2016 2:22 pm 
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Excellent point and I understand. None of us would want to live too close to HV global power lines, and I personally would far prefer a decentralized SMR future to minimize the danger of massive power failure due to many potential reasons, not limited to solar flares, EMPs, terrorists, etc.

But you are right, we would need to spread the collection side of things over massive areas and up the voltage dramatically. Not sure what the cost would be nor which countries could afford to participate. My fear is the long lines we have and the continued expansion of distantly connected solar plants (as well as other power plants requiring long lines) pose a risk that is becoming worrisome. Was it the 1870s when London got hit? Today I fear that would result in massive lose of life.

In a nutshell we need to think denser and smaller not the other way around.


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PostPosted: May 02, 2016 2:47 pm 
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It turns out that the price advantage that conventional power lines have over something underground, for example gas insulated lines, shrinks as the voltage is increased (for AC at least).
400kV GILs are 6-8 times the price of overheads, but by 1200kV this is down to 2-3 times.
By 1500-2000kV it might be close to breakeven.
And GILs do not produce external magnetic fields and might be more resistant to geomagnetic storms.

[This si thanks to the fact that power lines get taller as the voltage increases, so the towers get far more expensive, whilst with GILs the tube only gets slightly larger and the tube diameter is a relatively small factor in the cost of the line. Especially since the aluminium content does not necessarily increase at all. (The conductor tube and outer tube get proportionally thinner walled as they get larger).]

EDIT:

Apparently the DC currents induced by geomagnetic storms can be protected against by fitting the line with series capacitors near the transformers that prevent DC or very low frequency currents from flowing.
This causes reactive power issues but that can be compensated by shunt inductors.


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PostPosted: May 02, 2016 3:46 pm 
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Very interesting... but complicated. I like the Faraday cage type insulation idea but still worry about putting more and more power down fewer and fewer lines. Failures happen. I don't know enough about power transmission to discuss the options. A major power company engineer told me our current grid is near the edge of failure and requires constant balancing with "tuned" load following to compensate for too much wind and solar for the current design. To make the situation better would apparently be a huge cost in infrastructure. Our entire infrastructure of bridges, roads, water systems, and power systems is in need of solutions.

Writing this series of notes is difficult for me because 35+ years ago I was promoting renewables strongly. End to end optimized sustainability was not quite as clear to me back then.


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PostPosted: May 02, 2016 6:09 pm 
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A global grid would enable access to very large quantities of hydro, tidal and such (for example the Penzhin power plant proposal would add 87,100MWe of intermittent but entirely predictable power) that would diminish the market for such things as wind turbines and solar panels significantly.

When there is no such thing as a stranded resource than Dynamic Tidal Power and Tidal/Hydro in the middle of nowhere starts to look like a good deal.

As for fewer and fewer lines, even a 1200kV GIL only handles ~10,000MWe, which sounds like a lot but in the context of a global grid isn't really.
We could be looking at Quebec level consumption for everyone in our global electric society, at which point 1200kV looks like a 132kV subtransmission circuit looks to us now.

EDIT:

Time for some random maths, from a textbook by one Hermann Koch (apparently a rather well known export in the field of gas insulated lines and gas insulated switchgar) the approximate surge impedance of a typical 6000A Gas Insulated transmission line rated for 1200kV is 78 ohms. That gives it a natural transmission power [Surge Impedance Loading] of approximately 18GWe.
However a 6000A rating limits it to only ~12.4GWe due to thermal restrictions.
(Assuming we use a single three tube-phase GIL with one spare tube to cover for a faulty phase, this gives an up time of > 99.995%.

12.4GWe is only ~0.7 SIL, which means if we go with the rather primitive, and not designed for these purposes, St Clair Curve, the longest the transmission line can be without running into serious loadability effects, and without any series compensation or shunt capacitance (which would logically be provided but this gives us a ballpark estimate for the distances we are talking about) of something like 800km.
Which is an awful lot.
Magnetically Controlled Shunt Reactors allow that to extend to thousands of kilometres.
Really 1200kV AC and 1100kV DC are almost enough to allow for an intercontinental grid as it is. ~10% losses would get you many many thousands of kilometres. Said ~12GWe transmission line (if properly compensated along its length) would suffer only ~285W/m in thermal losses. Which translates into 1% per 435km at rated thermal load.
1500kV or more lightly loading circuits with increased shunt compensation would cut that even further [At 10GWe that would increase to 1% per 540km].


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PostPosted: May 03, 2016 2:46 am 
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The future of wind and solar power is limited and depends on storage to give the power produced a time shift to actual requirement.
The best storage is water pumping and the best sites are already taken.
However, the windmills have big towers which could be optimised to function simultaneously as compressed air storage. Compressed can be produced directly from shaft power saving on generators and water and water pumps.
If available close to point of use, the compressed air can be used directly as a power source at lower cost. It is ideal for air conditioning with heat pumping. Pneumatic motors are a very old technology and could be kept alive at low cost for limited work. Even if required to be eventually converted to electric power due to distance between generation and use,, not more than 20% of windmill generation capacity would be required. Iit should be the same or lower proportion than pumped water storage. Land use will be less.
As a major fringe benefit, modified towers will have a larger sunny area which can be also used for photovoltaic power. This is best used for electronics and lighting.


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PostPosted: May 03, 2016 3:56 am 
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rc1111 wrote:
Very interesting... but complicated. I like the Faraday cage type insulation idea but still worry about putting more and more power down fewer and fewer lines. Failures happen. I don't know enough about power transmission to discuss the options. A major power company engineer told me our current grid is near the edge of failure and requires constant balancing with "tuned" load following to compensate for too much wind and solar for the current design. To make the situation better would apparently be a huge cost in infrastructure. Our entire infrastructure of bridges, roads, water systems, and power systems is in need of solutions.

Writing this series of notes is difficult for me because 35+ years ago I was promoting renewables strongly. End to end optimized sustainability was not quite as clear to me back then.


When looking at offshore generation, I found that the UK grid prefers incoming connectors to be 1GW or less, to provide redundancy and not to overload one connection point. So some of the big wind farms have planned multiple GW HVDC connectors.

It also seems that under water HVDC connectors cost about $1 billion for 1GW for 1,000km.

I also saw figures that the German North-South grid upgrades - subject to NIMBY protesters - will cost 10s of billions of Euros. Paid for by all electricity users.


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PostPosted: May 03, 2016 3:59 am 
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E Ireland wrote:
It turns out that the price advantage that conventional power lines have over something underground, for example gas insulated lines, shrinks as the voltage is increased (for AC at least).
400kV GILs are 6-8 times the price of overheads, but by 1200kV this is down to 2-3 times.
By 1500-2000kV it might be close to breakeven.
And GILs do not produce external magnetic fields and might be more resistant to geomagnetic storms.



How would this relate to the proposed power lines from the planned Moreside power plant (>3GW), across the Lake District, that has recently been in the news?


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PostPosted: May 03, 2016 8:42 am 
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alexterrell wrote:
E Ireland wrote:
It turns out that the price advantage that conventional power lines have over something underground, for example gas insulated lines, shrinks as the voltage is increased (for AC at least).
400kV GILs are 6-8 times the price of overheads, but by 1200kV this is down to 2-3 times.
By 1500-2000kV it might be close to breakeven.
And GILs do not produce external magnetic fields and might be more resistant to geomagnetic storms.



How would this relate to the proposed power lines from the planned Moreside power plant (>3GW), across the Lake District, that has recently been in the news?


Moorside is being connected using standard (for the UK) 400kV circuits.
Which render GILs horrendously expensive. This is why only a small part of the line length will be buried.
If I was in charge I would fit a 1200kV GIL circuit all the way down the spine of the country, and put about six reactors at Moorside.
But I am clearly not in charge.


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PostPosted: May 03, 2016 12:08 pm 
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macpacheco wrote:
Until we admit that the world's energy market has subsidies EVERYWHERE, and that there would be NO NUCLEAR POWER without the implicit subsidy the US/Russian navies gave to nuclear energy R&D.

Most people do not realize that the whole nuclear power industry was created by ADM Rickover to subsidize his nuclear navy. It takes a certain amount of expense every year to keep expertice alive and well enough to support a technology. That expense was becoming too great for the Navy to maintain on its own so it created the Commercial Nuclear Power industry to maintain it for them. Since then, FedGov R&D has been for issues the current industry at best tolerates, at worst, hates. "Subsidies" are mainly a lie when it comes to commercial nuclear power. When Vogtle and Summer new builds come on line, THEN there will be a subsidy that is akin in kind if not magnitude to wind subsidies.

Personally, on the grid, I think all subsidies should be dropped in favor of the Stick and Carrot Method.

https://www.facebook.com/pages/Stick-an ... =bookmarks

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PostPosted: May 03, 2016 2:49 pm 
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E Ireland wrote:
alexterrell wrote:
How would this relate to the proposed power lines from the planned Moreside power plant (>3GW), across the Lake District, that has recently been in the news?

Moorside is being connected using standard (for the UK) 400kV circuits.
Which render GILs horrendously expensive. This is why only a small part of the line length will be buried.
If I was in charge I would fit a 1200kV GIL circuit all the way down the spine of the country, and put about six reactors at Moorside.
But I am clearly not in charge.


That would make an interesting Plan B in case Hinkley doesn't get built.


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PostPosted: May 03, 2016 4:01 pm 
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alexterrell wrote:
E Ireland wrote:
alexterrell wrote:
How would this relate to the proposed power lines from the planned Moreside power plant (>3GW), across the Lake District, that has recently been in the news?

Moorside is being connected using standard (for the UK) 400kV circuits.
Which render GILs horrendously expensive. This is why only a small part of the line length will be buried.
If I was in charge I would fit a 1200kV GIL circuit all the way down the spine of the country, and put about six reactors at Moorside.
But I am clearly not in charge.


That would make an interesting Plan B in case Hinkley doesn't get built.


Fighting the NIMBYs to get permission for a nuclear power station is very expensive.
We might as well get 5+GW (preferably 10+GW) out of each and every station built.


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PostPosted: May 03, 2016 11:02 pm 
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E Ireland wrote:
Fighting the NIMBYs to get permission for a nuclear power station is very expensive.


What I find somewhat infuriating is that while in nations like the USA the NIMBYs can keep us from having nuclear power while in China the NIMBYs don't show up because they have the threat of being dragged away and shot for speaking out against the government. I would never suggest we do away with our freedoms to speak our minds, assemble peaceably, or have our concerns heard by the government. What a nation like China can do is move on even if such things are not popular. If I were king of the world I'd certainly want to see clean and plentiful energy like nuclear fission happen and if I were king it would certainly be tempting to have the idiots holding up the project by standing in front of the bulldozers get run over. Because of this temptation it's probably a good thing I'm not king of the world.

We will have the USA powered by nuclear power someday. I say this because I recall a bit of insight often attributed to Winston Churchill, Americans can be counted on doing the right thing once all other possibilities have been exhausted. There will be a point where these NIMBYs will either disappear on their own or be overwhelmed by a vocal opposition. This is because every other energy source gets more expensive with time while nuclear gets cheaper. Even the little research that is happening in nuclear power we still see advances in the technology that can make it dominate. At the same time fossil fuels get more expensive and the alternative energy sources like wind and solar will get more expensive with it, this is because the materials used to make wind and solar has relied on processes powered by fossil fuels.

China and other nations will demonstrate to the world how nuclear power can be done cheaply and safely. If we allow the NIMBYs to prevent the USA from keeping up with them then we will be importing our nuclear power plants from China before long.

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PostPosted: Jun 06, 2016 6:42 am 
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Solar cells for the domestic use simply have a price problem.
What solar needs:

Perovskite or dye sensitized solar cells, at a cost of 50€/m²
lightweight cells, sheets in plastic envelope
ultra cheap and fast installation ---> i envision a fast deployment system via autonomous quadcopters.
Drones operating in duett like fashion like honeybees can carry 100m² of solar cells (100µm thickness/a few kilos/100 sheets) .One drone replaces, one installs new panel.
A small truck drives along the street carrying 50,000m² sheets of solar cells ready to be fetched by the two drones. (they could replace this amount of cells every 4 days!)
two drones can do the work of dozens and dozens of workers if they operate fast enough.
MOunting rack for the cells should be as simple as possible. Maybe even a system that could unfold itself.
Once deployed it wouldn't even matter if the cells would only last up to 10 years.
Drones could change them super quick, with a very convenient mounting system.
Solar drones monitor quality of cells and decide themselves which one would need to be changed.

We need cheap solar cells that can be manufactured fast and mounting methods that are super easy fast to reduce costs.
We need a bee hive of solar drones.
Perovskite is our nectar.


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PostPosted: Jun 07, 2016 1:58 pm 
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Tim Meyer wrote:
How is what you're discussing relevant to the effort to derive energy from thorium?

cerebral: Under the topic: Is solar energy use increasing exponentially?, please note the reply of our host here:
Kirk Sorensen wrote:
It's not. Tired of checking the forum only to see discussions about solar energy. You can go talk about that somewhere else, ad nauseum. Topic locked.

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PostPosted: Dec 16, 2017 8:24 pm 
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Eliminate the Wind Production Tax Credit

Tax Compromise Keeps Wind and Electric-Car Credits, Source Says


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