Alternative Way to Harness Solar Energy

Not usually. Usually they reduce peak power demand, and add a little bit of generation and distribution with their own capital.

I agree. Perhaps I was unclear?

But the storage problem is also a chicken and egg sort of problem - there are several storage methods awaiting sufficient call for their refinement and installation (I'm curious about flywheels, myself, but one of the really interesting notions I've run across was the production of swapout charged batteries or fuel cells for cars. The central power area - patch of Mojave desert, whatever - would charge thousands of such, and electric cars would swap them at "gas stations", exchanging for their depleted one which would be returned to the power setup).

 

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Not at all; I was agreeing with you. Perhaps I was unclear?

Interesting. It seems that something along those lines (i.e., materially storable and shippable) is going to be required, in order to leverage our existing infrastructure.

But there's also something to be said for distributed power; a solar panel on every roof doesn't need a fancy storage/distro network to power your home (although the utilities will still need such systems to properly interface with distributed generation).

 

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I said rooftop etc. solar using the gird as back-up and storage adds to the peak power demand. You replied:

I agree that often on Sunny day when the peak load happens that days peak is lower as solar generation is supplying part of the demand.

But when it is raining - clouded over at the time of peak demand the roof top solar want s power - adds to "Peak Demand" just like the non-solar customer. The difference is the non solar customer is using and paying for grid power every hour of the year; but the solar user only uses and pays for about 10% as much as usually generates his needs and pumps some excess into the gird to run his meter backwards.

If you want to say the solar guy does not add to peak demand that is ok, BUT then you must admit he is not being a customer most of the time so that makes the utilization (or load factor) of the central facility worse. The cost of electric power is mainly the capital cost; energy cost is a tiny fraction or zero if a hydro-electric plant. The best way to make the cost per KWH low is to have that capital being used 100% of the time. I.e. a 100% load factor. The solar user ALWAYS makes the load factor or utilization worse - increases the cost of electric power.

The way electric utilities work is to have a base load generation capacity that runs essentially 100% of the time. It is the most efficient and least costly component of their generation capacity. Typically their nuclear plant if they have one or a coal fired plant if not. When the load exceeds that generation capacity they fire up the oil burning plants if they have them. When the load exceeds the generation of both those, they turn on the inefficient but cheaper capital gas fired generation.

What the solar user does by making the load factor lower it to increase the use of the gas inefficient gas turbine units.

Your statement is flat out wrong. Try to defend it if you can.

Any user who only wants on rare occasions, set by random factor like the weather, will at least a few times per year want power at the peak demand time. Servicing him will require more gas turbine generation and add to the cost per KWH.

The "flip side" is the great reduction some electric companies charge per KWH to users who let them control their electric hot water tank heater (via phone line) - I.e. the electric company can increase the demand at night when it is low and turn some off when near the peak. - Unlike solar connected customers, that increases the average load factor (capital utilization) and they can (and do) pass on part of the saving (in capital cost) to the customer.

 

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Look up grid energy storage, you will see there been a lot of development even installation of MW class NaS batteries for wind farms.

 

I am not saying that all central storage systems must cost more than gas turbines to met peak demand. In fact pumped hydro-storage is already a cheaper way to met peak demand than gas turbines, but there are few places where it is possible.

There is some serious efforts to use pumped air storage in old salt mines also, but I do not know of any on line.
My money is on un-maned super-flywheel substations - saves on distribution losses at peak also* - as the best bet for replacing the gas turbine in general use, but not where gas is essentailly free / as now flared.

I will not bother to search about wind power storgage as if it exists if is not with a level playing field but like wind power itself, in most cases, receiving subsidies and / or tax relief. If you want to give link, I will read it.

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*By edit as some may miss my point here I give a numercal example. Assume half the time currently the wire is carying 6 Amps and half the time only 2 Amps. If that same energy were transfered at a steady 4 Amps then the losse are proportional to 16 but the "half and half" losses are (36 + 4)/2 = 20, or 25% greater than need be.

 

That is where nano based battery systems come into play....

 

Is this exactly what it sounds like? Use energy to lift water as to give it gravitational potential energy? A very, very, very low-tech battery. Making it close to 100% efficient is the hard part.

I suppose evaporation coupled with wicking materials (nanotubes, crazy metals) could do the job.

 

Yes that is it. I think that the fraction recovered of the energy put into this storgage system is as high and any other storage system, with the possible exception of flywheels. All chemical storage system convert a significant fraction of energy into heat. (full cycle considered put it in and then take it out)

As a general rule, systems that make little full cycle heat are most effcient. Pumped hydro make essentially zero heat, but there is KE in water leaving the turbines. (It could be used too, but does not pay for the greater capital cost of doing so.) A super flyweel spinning on magnetic bearing in a vacuum is best if used in a daily cycle. I think it may be better than most chemical batteries at just "storing energy" also as they have a "self discharge" current. Rechargeable NiCd battery has a high self discharge rate if you have used them in camera (Will fully discharge in a few weeks, in less than a month anyway.)

I believe ConEd (NYC's power company) has a small pumped storage unit that takes Hudson river water up to a lake they own in the Katskill Mountains to increase the use of cheaper base load power and reduce the use of expensive gas turbine generation when peak loads occur. The only good thing one can say about gas turbine generation is that the captial cost / KW of capacity is lower so if some of the capital invested is only used 5% or less of the time it should be low capital cost units, not high cost base load units.

The efficiency of that unit is well above 100% as much of the water that comes down thru the trubines is lifted up by the sun (called rain) not by the pumps. (lake has no outlet.)

 

Very interesting. It seems that there are multiple advantages to building dams. You can get hydro-power as well as use it as a battery for other sources of renewable energy.

However, in all truth, gravitational energy does not store significant amounts of energy. If you elevate 1 ton 100 meters, this is only .272 kWh, or about 3 cents of electricity. I suppose this scales quickly when you're talking about lakes. A square lake 3 miles to the side could store quite a bit of energy, depending where the water came from. There are certainly geographical limitations.

Flywheels are a potential, but effective and enormous magnetic bearings are necessary. I'm not sure why flywheels aren't used more..

 

Yes China is building a wind farm with the same peak generation capacity as the worlds largest dam not too far from the Three Georges Dam. They call this wind farm "Three Georges on land." When there is stong wind they will save water behind the TGD. When the wind dies down, they will release water thru the turbines -There by achieving an assured electrical generation equal to at least the peak of either and some times (rainny season) about twice the out put of the dam alone.

China is far ahead of the US in its efforts to use solar energy,is the maker of most of the solar cells in the world too. And building supercritical coal fired unit generators that get at least 3 KWH out instead of only less than 2 KWH for the same amount of coal. China will need to contiune to use coal for many years as even with bring on line a new plant ever week (a nuclear ever month) their grow rate will not let them close down all the existing coal plants.

BYD is expected to make 400,000 electric hybrid cars this year. They go 65 Km on a full charge and GM's volt hopes to go 50Km. They cost ~half what the Volt will cost. The BMD car is four door and very good looking (I think more attractive than the Volt.) The first Volts will be available for sale in late 2011, assuming there even is a GM / USA then. (GM is setting sales record in both China and Brazil. In May sold more cars in Brazil than any other month in their entire 84 year history in Brazil.)

Warren Buffett's trickle down tax saving allowed him to get 10% ownership of BYD motors. - Republican Trickle Down works, but the investment goes to where the expected returns are greatest - not to the US with less than 20% of China's GDP growth when GWB was granting the already rich tax relief.

Unfortunatelly, those more modern factories in China will be closing non competive US ones for years. Hell, Chrysler now has a production team in Poland studing how they make a small Fiat car every 55 seconds.

The US should be embarassed - leaning from POLAND how to make a cost effective, modern, car factory!

 

Surprisingly, the Eastern European countries that belong to the EU have been growing very quickly since the fall of the Soviet Union. There are large investments to modernize these countries as they are untapped markets, much like capitalist China.

I was thinking about using some kind of condensation machine.. evaporate water, and have it condense at a higher altitude. There would clearly be inefficiency. Flywheels are almost as low tech, but there is the need for a magnetic bearing. Pseudo-magnetic bearings are much cheaper and could be used to store large amounts of kinetic energy.

 

If you drop the condensed water thru a turbine that in principle is a good idea for converting heat into power, but here are a couple of reasons why it is not done:

(1) The power level possible is very low and the capital cost (for the tall chimney / tower) is very high.

(2) The outside air temperature drops with altitude, so to avoid the vapor condensing on the inside of the tower / chimney walls and uselessly running down them back to the base boiling pot, you will need extremely good insulation. As the surface available for heat to escape thru the walls is very large most of the thermal energy input will be lost by this wall condensation, unless the insulation is about 100 meters thick - That does not help with the capital cost problem.

A somewhat similar idea is the sea water / fresh water fountain: A vertical tube in the ocean, say a mile long, with the bottom end covered by an osmotic membrane and the interior filled with fresh water. Here there are no thermal loss problems. The lower density of fresh water makes the pressure on fresh water side of the membrane less that on the sea water side. This pressure difference drives "reverse osmosis" -i.e. there is a flow, not very fast, of pure H2O from the sea water thru the membrane into the fresh water.

As the total weight of the fresh water filled tube is less than the sea water it displaces the top of the fresh water tube is floating above the sea surface. The same mass of fresh water which is entering the bottom, via reverse osmosis, is flowing over the top of the tube and falling back to the sea level, except I put it thru a turbine. This system provides both power and drinking water in the middle of the ocean, but is also very expensive with little output!

I will let you think about why this is NOT both a perpetual motion and over unity device.

{Made blue as I will link to this in the perpetual motion and over unity device thread.}
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Now on magnetic bearings - First I only know some physics, not any facts about them.

You must avoid inducing electrical currents. This means that they are composites of very fine magnetic dust in a nonconductor matrix.

They must be repulsive - E.g. an N pole against an N pole. This means there will be a stability problem. I do not know how it is solved - Probably with more magnets that do not support, but keep the axis of the spinning mass stable. Perhaps the S pole of the spinning mass bends to be magnetic flux radial (the associated N pole flux being vertical to support against the static N pole below it) Then a ring of S poles around the spinning S Poles might do the stabilizing job. -Anyway that would be my first try.

 

The best way to harness solar power is still a little off our tech...
I ain't sure you will will accept this idea but I will pitch it nonetheless!

In 1992 a new type of laser has been develop, it was a plasma laser. The principle was kind of simple. The laser was going through a plasma cavity, where it was causing modulating shock waves that results in the amplification of the laser output. With this technology, they were hoping to reach 1000Tw of power from a laser device fitting in an apartment room!!

So knowing this principle, you take this and jump to using our sun as the plasma source that will amplify the laser beam. Because our sun is just a huge plasma (after you breach the cooler surface). So we only need to go the other side of the sun to grab the extra powered laser and convert the excess into gain and voila... You get enough energy to travel anywhere you want in our solar system. But of course, it won't happen tomorrow...

 

Aín't never gona happen for simple fact the sun is very opaque. A typical photon released at the cener of the sun will be absorbed an re-emitted (Not same wave length except by chance, zillions times a zillions of times before that energy random walks to the surface. I forget the typical transit time from center to surface but many thousands of years seems to be about right.

The sun is essentially a black body ALL LAYERS OF IT. Black bodies are prefect absorbers. Nothing will come out the other side! The laser pulse will ad an extremely insignificant energy to the spherically symmetric existing radiation.

Hard to imagine anything as false as your idea here.

 

I kinda thing energy storage would be a little less necessary (but definitely not unnecessary) if multiple forms of renewables were employed. For instance, solar and wind would compliment each other, for when the clouds come out to choke out the sun, wind picks up as a front moves through, roughly compromising the lack of energy from solar.

I kinda need to look into the flywheel research already done, but what are the gyroscopic ramifications of it? Does the whole thing need to be in a gimble inside a vacuum chamber? It sounds like a vacuum pump is somehow involved, eating up power?

The whole green movement seems a tad silly to me since I'm not 100% on the global warming bandwagon, but that aside, as an aerospace engineer, the green movement looks awfully lucrative... *runs off to design a new windmill... or something*

 

Vaccuum is a One time cost with tiny pump - forget it.

The fact earth rotates does complicate things. To first order making spin axis parallel to Earth's spin axis solves that but as unit is not located at either pole, there is a gravitational torque problem when axis is not locally vertical. I forget the details but this problem can be solved. Perhaps you give just enough gravity torque to precess it just right? - I would need to read up on it again as memory is failing me on this.

 

Yes it is hard to imagine, but with the years, I have come to the conclusion that nothing seems to be what it is. Opacity of the sun won't be a factor if the laser wavelength goes into the gamma... But as you say, this is out of reach of modern science until a few decades from now!
But remind something, if it shall ever work, shall it makes the most effective way to harvest energy from the sun? I think yes, and this is why I have put it here

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No I did not say it was "out of reach" for a few decades.

I said it is IMPOSSIBLE for any photon of any wavelength. Even if one ignored all the absorptions, the Compton scattering ALONE would make the beam lose all the photons energy in the zillions of scattering off the zillions of protons and He ion in the sun, but even if there were no energy loss in Compton scattering to the recoiling charged particles, all points on the solar surface where the photon eventually random walked out of the sun after many angular scattering would all be equally probable, not your “amplified beam" coming out the far side!

Even if the entire electrical generation capacity of the entire Earth were 100% converted in to the beam sent to the sun, when this energy emerges equally over the entire solar surface it might just be a barely detectable brief increase in solar intensity, if you had very high resolution instruments measuring it. A one minute duration beam sent to the sun would still be random walking around inside the sun hours later, assuming falsely that it was not absorved, I serious doubt that the increase is even detectable. (I am guessing this based on the fact that the total energy produced on Earth in a year is delivered to Earth by the sun in less than an hour and the Earth only get an extremely small fraction of the sun's total radiation.) Such high resolution instruments are many decades away or will never exist.

Your gamma ray photon would be degraded into a radio wave, I think, before it could travel even 10% of the solar radius inside the sun.

You are badly lacking understanding of some very simple physics. -Read about Compton scattering: See the photon both loses energy and changes direction of travel with each of the zillions of Compton scatterings it would experience as it attempt to transit straight thru the sun.

PS: I take back what I said earlier about your obviously knowing some plasma and laser physics. It is now quite clear you understand very little of that. Clear that you only read some true article and misunderstood what it was stating OR read some false article and did not know enough to know it was false.

BTW, back when I was involved in efforts to evaluate the "death ray" lasers for shooting ICBM etc. out of the heavens, the very existence of what you called "slamming" was classified. I.e. when you try to put too much energy thru the air, it ionized and does some Compton scattering, even in the density of air, in a few meters to destroy the beam. Think what trying to go thru the sun would do to the beam! (That "slamming" was why, after it was discovered, that the Air force modified a large, high altitude plane to see it was feasible to shoot down a cruise missile if it was high above it in very thin air. I think the US government wanted the USSR to waste a lot of money too with a ground based systems and discover “slamming” for itself.)*

If anything, your high energy gamma rays would produce slamming in air in even a shorted distance! (Not individually gamma rays, but a high energy beam of them.)

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* As I recall, it was not called "slamming" back then, but "blooming." The beam sort of opens up like a flower as the small angle or "forward" Comption scattering is much more probable than large angle scattering.

 

Its interesting to know that you have worked in the field!!
And you are right this isn't really my field at all, but I do understand a lot of the concepts involved, and somehow it has always been easy for me to figure what was possible, and what wasn't, even if sometimes, I couldn't well explain it. So I agree with you to say, that this concept isn't feasible considering our current knowledge. As you say a few years ago, "slamming" was classified. But now we have molecular photons, photomanipulator laser and on...

Actually, light is pretty much like matter but it is very evasive when it comes to manipulating it with our current technologies. It has also great quantum proprieties that we do not yet understand well, but with light we can also teleport information and yet could do many other things that we have yet to discover...

Anyhow, it is easy to see the a typical a brute force laser won't do the job, but knowing so little, what we can do with photons, I presume that we could find ourselves surprised a lot if we keep looking! So the trick is to keep our mind open to every possibilities! Maths do the job with matter but when it comes to quantum mechanics, it is pretty much a stub.

So I am VERY surprise that as a scientific, you claim that this isn't impossible... It would be better claiming that it is impossible now!!

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By the way, I just want to say that sometimes I do not take the time to detail my assertion as I am greatly deprived of sleep these days (3 to 5 hours sleep a day...). Also, I might add that my field is Paleontology, and therefore has indeed little to do with your field, but I am indirectly involved in the field for a while, so I might look a little chaotic to follow!