High efficiency solar

[Old Rocks]

Real research that will lead to very cheap solar power.

Quantum dots for highly efficient solar cells - physicsworld.com

The efficiency of solar cells could be increased to more than 60% from the current limit of just 30% according to new work by scientists in Minneapolis and Texas. The new work involves capturing the higher-energy sunlight that is normally lost as heat in conventional devices using semiconductor nanocrystals, or quantum dots.

The maximum efficiency of conventional solar cells made from silicon-based semiconductors is limited by theory to around 31% – and the best performing affordable commercial devices are less than 20% efficient. This is because in typical devices, photons with energies above the semiconductor's bandgap generate "hot" charge carriers (electrons and holes) that quickly cool to the band edges in a matter of just picoseconds, releasing phonons (vibrations of the crystal lattice, or heat). If the energy of these hot electrons could be captured before it is converted into wasted heat, solar-to-electric power-conversion efficiencies could be increased to as high as 66%, say scientists.

 

[Quantum Windbag]

Real research that will lead to very cheap solar power.

Quantum dots for highly efficient solar cells - physicsworld.com

The efficiency of solar cells could be increased to more than 60% from the current limit of just 30% according to new work by scientists in Minneapolis and Texas. The new work involves capturing the higher-energy sunlight that is normally lost as heat in conventional devices using semiconductor nanocrystals, or quantum dots.

The maximum efficiency of conventional solar cells made from silicon-based semiconductors is limited by theory to around 31% – and the best performing affordable commercial devices are less than 20% efficient. This is because in typical devices, photons with energies above the semiconductor's bandgap generate "hot" charge carriers (electrons and holes) that quickly cool to the band edges in a matter of just picoseconds, releasing phonons (vibrations of the crystal lattice, or heat). If the energy of these hot electrons could be captured before it is converted into wasted heat, solar-to-electric power-conversion efficiencies could be increased to as high as 66%, say scientists.

From your link.

The researchers didn't expect to see hot-electron transfer in action, just the transfer of ordinary electrons. "We realized that, to improve the way in which we assemble solar cells based on quantum dots, we needed to understand the fundamentals of electron transfer from the quantum dots to semiconductors," team member Eray Aydil told our sister website nanotechweb. "Zhu and our co-advised student Will Tisdale (who will soon obtain his PhD) developed the method reported here to detect this electron transfer. The fact that we ended up seeing hot-electron transfer was a very nice surprise."
Aydil adds that much work still needs to be done before we see solar cells with efficiencies of over 60%. "I think all of us and everyone working in this field would caution against making predictions on when we will see (if ever) 66% efficient solar cells. However, if such high-efficiency solar cells based on hot-electron transfer are to be become a reality, we have shown the necessary first step."
The team will now attempt to detect the transferred electrons as current and make solar cells that exploit hot electron transfer, even if the efficiency is still low.

That means they aren't even close to making this work, and the first high cost prototypes are probably going to be less efficient than current solar tech.

 

[Old Rocks]

Technology Review: Silicon Nanocrystals for Superefficient Solar Cells

Silicon Nanocrystals for Superefficient Solar Cells
Research shows that silicon can wring two electrons from each photon of incoming light.

By Kevin Bullis
Wednesday, August 15, 2007


A typical solar cell generates only one electron per photon of incoming sunlight. Some exotic materials are thought to produce multiple electrons per photon, but for the first time, the same effect has been seen in silicon. Researchers at the National Renewable Energy Laboratory (NREL), in Golden, CO, showed that silicon nanocrystals can produce two or three electrons per photon of high-energy sunlight. The effect, they say, could lead to a new type of solar cell that is both cheap and more than twice as efficient as today's typical photovoltaics.


Souped-up silicon: A micrograph of a seven-nanometer chunk of crystalline silicon, called a nanocrystal or quantum dot. Such structures could dramatically increase the efficiency of solar cells.
Credit: Arthur Nozik, National Renewable Energy Laboratory
As in earlier work with other materials, the extra electrons come from photons of blue and ultraviolet light, which have much more energy than those from the rest of the solar spectrum, especially red and infrared light. In most solar cells, the extra energy in blue and ultraviolet light is wasted as heat. But the small size of nanoscale crystals, also called quantum dots, leads to novel quantum-mechanical effects that convert this energy into electrons instead.

 

[Old Rocks]

High Volume Production of Quantum Dots for Solar Cells and Other Applications

Solterra Renewable Technologies will be producing and distributing a Thin Film Quantum Dot PV Solar Cell, which is differentiated from other traditional PV cells by a unique technology that can result in lower cost, higher efficiency, and broader spectral performance. Solterra's Quantum Dot Solar Cell can achieve a dramatically lower manufacturing cost per watt in part, because we can manufacture our own quantum dots using a patent pending, revolutionary process that results in the production of extremely desirable, high quality tetrapod quantum dots at a cost savings in excess of 95%.

 

[KissMy]

I have heard all this before 6 years ago but it was about Quantum Dots Solar paint that could be painted onto car bodies & generate 5 times more power than current solar panels.

Bottom line is currently anything that says it operates with quantum anything is a money scamming hoax just like the over-unity generator. The reusable Quantum water disk that you put in your washer instead of soap was one huge scam that suckered millions. Some day when they perfect the nanobot usage on a large scale then they may be able to use them to construct some quantum dots. I bet that will be at least 15 years from now.

 

[Old Rocks]

tunnel diode

 

[KissMy]

The EU’s Solar Science Fiction

Solar energy in Europe remains, by far, the most expensive energy source and it will be years before it can compete, even with other renewable sources. Germany, Italy, and especially Spain, once shining examples for the solar industry, have backtracked on their initial embraces of solar and are now cutting subsidies. Indeed, earlier this year, Spain scrapped subsidies for new solar power plants as part of the effort to cut its massive debt. Now Spanish officials are readying legislation to reduce feed-in tariffs by almost 45 percent on existing solar power plants.

 

[editec]

15 years from now beats never.

I believe that the current manifestation of our energy problems will largely be solved in our lifetimes, too.

Let us assume it will be solved and that we will migrate in a generation or so away from hydrocarbon energy and the resulting pollution problems they entrail.

We are still going to have the problem of too many men polluting their own nest.

In fact, having cheap and abundant energy that is not spewing out CO2 will likely increase this over population problem.

As the rest of humankind -- 2 billion of which are now living at a subsistance level -- start competing for resources that today they are not in the market for today, new problems will manifest that probably aren't immediately apparent to us now.


I don't know what the next strategic resource crises will be, (I suspect we're going to have a few of them in our lifetimes) but I suspect H2O is already on that list, for example.


Bottom line?

We have too many people to sustain the quality of life that we in the industrialized world have come to expect.

I believe that sooner, rather than later, mankind is collectively going to have to do something about the over population.

Just as the economists remind us that there is NO FREE LUNCH, so too we must acknowledge that the environment (which is really the economy in the raw) is telling us the EXACT SAME THING.

 

[KissMy]

15 years from now beats never.

I believe that the current manifestation of our energy problems will largely be solved in our lifetimes, too.

Let us assume it will be solved and that we will migrate in a generation or so away from hydrocarbon energy and the resulting pollution problems they entrail.

We are still going to have the problem of too many men polluting their own nest.

In fact, having cheap and abundant energy that is not spewing out CO2 will likely increase this over population problem.

As the rest of humankind -- 2 billion of which are now living at a subsistance level -- start competing for resources that today they are not in the market for today, new problems will manifest that probably aren't immediately apparent to us now.


I don't know what the next strategic resource crises will be, (I suspect we're going to have a few of them in our lifetimes) but I suspect H2O is already on that list, for example.


Bottom line?

We have too many people to sustain the quality of life that we in the industrialized world have come to expect.

I believe that sooner, rather than later, mankind is collectively going to have to do something about the over population.

Just as the economists remind us that there is NO FREE LUNCH, so too we must acknowledge that the environment (which is really the economy in the raw) is telling us the EXACT SAME THING.

So lets pass healthcare to allow more births & fewer deaths?

 

[Old Rocks]

Universal Health Care has nothing to do with increasing population. Many of the industrial nations that have UHC have a negative population growth.

 

[Charles_Main]

Universal Health Care has nothing to do with increasing population. Many of the industrial nations that have UHC have a negative population growth.

Yes they do, and that is part of the reason they can not sustain their programs.

See here in America we have a ready made supply of new blood to allow to come in illegally then make citizens, and we will need it to sustain all this welfare.

 

[sparky]

the general $$$ per solar watt is comming down according to Home Power magazine's gurus

~S~

 

[edthecynic]

I have heard all this before 6 years ago but it was about Quantum Dots Solar paint that could be painted onto car bodies & generate 5 times more power than current solar panels.

Bottom line is currently anything that says it operates with quantum anything is a money scamming hoax just like the over-unity generator. The reusable Quantum water disk that you put in your washer instead of soap was one huge scam that suckered millions. Some day when they perfect the nanobot usage on a large scale then they may be able to use them to construct some quantum dots. I bet that will be at least 15 years from now.

Some hoax!!!

The Quantum dot nanotechnology panels are already available. The Westinghouse Solar panels will soon be distributed through Lowes.

Nanosolar: Nanosolar Utility Panel

The Nanosolar Utility Panel is the industry’s most cost-efficient solution for utility-scale deployment of solar power.

Through its systems-optimized design, the Nanosolar Utility Panel delivers significant balance-of-system cost savings relative to conventional thin panels:

Based on independent third-party evaluation (including time-clocked field tests for labor time), the Nanosolar Utility Panel saves up to 40% on mounting materials, mounting labor, cabling materials, and cabling labor relative to conventional thin panels.

Roof Mount Systems: Thin Film | SunLink

The initial thin-film solution is being developed in partnership with thin-film manufacturer, Nanosolar, as part of the Solar America Initiative award by the U.S. Department of Energy.

Nanosolar: Large Roofs

The Nanosolar SunLink solution is an innovative, extremely low-materials-cost, “lay-up” mounting system for large, flat roofs that usually requires no penetration and no additional ballast.

Third-party studies have shown cable connect times reduced by as much as 85% and total-installation time by as much as 25% versus industry-standard systems, significantly reducing installation cost.

Photo Gallery

 

[KissMy]

I found 2 cargo containers full of thin film solar panels 93kw worth of output on ebay for $1.40 per watt. That is cheap enough to pay back in 7 years. Problem is I only need 5kw to 15kw worth. All other panels run about $2 per watt. Does anyone want to split a load?

 

[jeffrockit]

15 years from now beats never.

I believe that sooner, rather than later, mankind is collectively going to have to do something about the over population.

Just as the economists remind us that there is NO FREE LUNCH, so too we must acknowledge that the environment (which is really the economy in the raw) is telling us the EXACT SAME THING.

And what will that "something" be that we do about over population?

 

[terroirist]

15 years from now beats never.

I believe that sooner, rather than later, mankind is collectively going to have to do something about the over population.

Just as the economists remind us that there is NO FREE LUNCH, so too we must acknowledge that the environment (which is really the economy in the raw) is telling us the EXACT SAME THING.

And what will that "something" be that we do about over population?

Well, we need to start by moving past the life vs choice debate. There is only a right to life (for the unborn) when our species is seriously threatened with extinction. Then we need to adopt a one- or two- child policy, but not like in China. Instead, there would be a market for unborn children in the sense that wealthy individuals who've run out could purchase the right to have an additional child from the poor, keeping poor (single) mothers from having numerous children like is so often the case. There could even be an additional tax on children born to fatherless children (that could get tacked onto alimony payments) OR for children born carrying alleles for various debilitating diseases (that really should be subtracted from the human gene pool wherever possible). Of course, certain exceptions exist, such as sickle-cell anemia, where a heterozygote (carrying only one copy of the gene) provides resistance to malaria (or other environmental disease).

After establishing a career, family, and "nest egg", these same women can purchase these childbearing rights back from a needy person who still has theirs. Not only would this empower women by giving them a lump sum financial incentive early in their lives, it would place a realistic price on having children that would enter into the decision to have a child that currently does not exist. It would surely make women rethink carrying a baby to term with an uncertain or lacking partner. It would also discourage (middle or lower-class) parents from keeping unborn children with serious medical conditions that will require expensive and/or ongoing treatment. All this while "capping" the rate of population change.

Another idea is to cap the amount of health care available to people within a national health care program, with exceptions for violent crime or natural disasters. That way folks who take care of themselves early in their lives have access to health care late in life, while those who don't (drug addicts, the obese, etc.) will run out early, and they will die relatively young. There just needs to be better incentives for healthy lifestyles in a national health care program in a egalitarian society like ours. Health is wealth, and such an institution like government health care should reflect this.

Coming back to the central topic of this thread, conventional photovoltaic technology is no panacea. Even the most advanced PV (solar-electric) panels will not produce, in its average useful lifespan, as much energy as it takes to produce the panel itself except in desert climates where the sun beats down nearly continuously. This doesn't even factor in the energy required for producing and disposing of the batteries that store the electricity (which must be replaced periodically). The only way solar-electric technology could provide us with a significant amount of our electrical needs is if we could find a way to cut down our consumption by 50% or more. Americans just consume too much energy, and ultra-efficiency won't save us in this regard, either. As Jevon's Paradox accurately illustrates, the more efficient we are at using energy, the more energy we will consume.

 

[Old Rocks]

15 years from now beats never.

I believe that sooner, rather than later, mankind is collectively going to have to do something about the over population.

Just as the economists remind us that there is NO FREE LUNCH, so too we must acknowledge that the environment (which is really the economy in the raw) is telling us the EXACT SAME THING.

And what will that "something" be that we do about over population?

First child is tax free. Every child thereafter costs 5% of income.

Make birth control free, readily available, and no questions asked.

 

[jeffrockit]

15 years from now beats never.

I believe that sooner, rather than later, mankind is collectively going to have to do something about the over population.

Just as the economists remind us that there is NO FREE LUNCH, so too we must acknowledge that the environment (which is really the economy in the raw) is telling us the EXACT SAME THING.

And what will that "something" be that we do about over population?

First child is tax free. Every child thereafter costs 5% of income.

Make birth control free, readily available, and no questions asked.

Won't change a thing. 1st putting a tax of 5% per child will do no good to the almost 50% that do not pay taxes. I don't have the numbers but am confident that many children are born into those low income, families so good luck collecting.
2nd regarding birth control. is it your contention that so many women become pregnant because birth control is too expensive? There are health clinics in almost any city that will provide FREE birth control. Besides that, how expensive are condoms now? as far as I can tell, birth control is readily available and who are you stating that is asking the questions that keep individuals from attaining BC?

One of the realities is that some. have many kids to garner that bigger piece of the welfare check each month, others simply do it out of ignorance. My position is if you have more than on child and have been on extended welfare, the next birth, you will not receive additional money. That would cut down on those that abuse the system. Simply put, if you are having children that others are paying for, you should lose that ability to have any more. I realize that sounds hard but the realities are they are not taking care of the ones they have already.