Solar Cells Can be Built Using Any Semiconductor

Status
Not open for further replies.

namecnassianer

Distinguished
Mar 10, 2010
21
0
18,510
0
Energy from the sky!

And it's free (almost).

This is where governments should be spending money, instead of on new landmines that render people asunder.
 

CaedenV

Splendid
[citation][nom]Nikorr[/nom]Whats the efficiency?[/citation]
my thoughts exactly, It would be great to have cheap panels, but unless we can make them near 20% efficient then it would take too much surface area to power the average home. But if it is efficient, and they can get it down the pipe in 5 years when I need to redo my roof then I will be a happy camper :D
[citation][nom]belardo[/nom]Oil companies will pay to keep this stuff off the market.[/citation]
They could try (and have tried for several years), but ultimately there is too much demand for the solar movement on all fronts. Solar (once we get it down to a cheap enough initial investment, and good battery tech) will take over the consumer/home market, and oil will be relegated to 'heavy' uses such as air travel, bulk transit (rails and boats), and military.
[citation][nom]hardcore_gamer[/nom]We have to stop our dependency on foreign oil asap. Right now, we are indirectly funding terrorist organizations.[/citation]
When things start moving solar it is going to make some huge changes in the world's power structure. Countries like the US will move to solar and natural gas/coal, while many European countries will move to solar and nuclear. 3rd world countries will then be stuck on oil, and desperate oil producing countries will make their lives a living hell.
Here in the first world we will see huge political shifts moving from the large influence of oil companies and centralized power grids to solar companies and an ever increasingly decentralized power grid which will potentially further the gap between the 'haves' and the 'have nots'. If you can afford your own power cells then you get 'free' power (or at least very cheap power) to do with as you please. If you cannot afford your own power cells, or live in a city where you do not have access to your own power source, then you will be forced to rely on power companies which will be coping with huge losses in business, while still being required to maintain a massive power grid. Hopefully we will find answers to these problems in time, but I think a lot of people overlook many of the potential problems that can occur as we move over to this new tech. As mentioned above, I'll be moving to solar regardless when it comes time to replace the roof.
 

CaedenV

Splendid
[citation][nom]hardcore_gamer[/nom]We have to stop our dependency on foreign oil asap. Right now, we are indirectly funding terrorist organizations.[/citation]
What happens when a bully is accustomed to taking your lunch money, and you stop giving it to them? Not saying that we should be giving them money; But when we stop (and we will) it will likely cause a lot of problems once they become desperate.
 

lamorpa

Distinguished
Apr 30, 2008
1,195
0
19,280
0
[citation][nom]belardo[/nom]Oil companies will pay to keep this stuff off the market.[/citation]
...just like the saltwater powered car?

(conspiracy theorists are always entertaining)
 

Adhmuz

Distinguished
May 26, 2009
21
0
18,510
0
The only issue I have with solar energy is this, what happens when it rains? or its overcast? Yes it's clean, its free, but it takes up a lot of land and at the end of the day the sun goes down, then what. Most free energy is so unreliable that its not feasible to have it power our infrastructure, Yet. It does contribute and help just not enough, and not on a global scale. Hydroelectric and geothermal, this is an area that needs better development, tidal power especially should be looked at more closely. There's massive potential for clean renewable energy, I just don't see it being developed until we run out of fossil fuels and by then the damage will be done and our atmosphere will be so polluted the oil companies will just start selling us the air we breath.
 

blood_dew

Distinguished
Apr 4, 2009
15
0
18,510
0
Solar gets WAY too much attention. I'm looking forward to next generation nuclear technologies. The grid CANNOT be powered by energy that is only on during the day, when it isn't cloudy. Before you say the Gov't should be spending money on solar look in to the potential alternatives!

Liquid Fluoride Thorium Reactors would be:
Cheaper, always on, far safer than today's Light Water Reactors, run on an energy source that we would literally NEVER run out of, and be able to reprocess transuranic waste from todays nuclear plants. They can also be built to desalinate water. All without producing ANY carbon. Also because it is thorium instead of enriched uranium you are literally looking at ENDING the threat of nuclear proliferation.
 

freggo

Distinguished
Nov 22, 2008
2,019
0
19,780
0
[citation][nom]Adhmuz[/nom]The only issue I have with solar energy is this, what happens when it rains? or its overcast? Yes it's clean, its free, but it takes up a lot of land and at the end of the day the sun goes down, then what.[/citation]

You combine a solar power station with some form of energy storage of course.
Can be anything from batteries to molten salt to water reservoirs etc.
Personally I'd use excess electricity to take humidity from the air, split it into Hydrogen/Oxygen and store the hydrogen. You can then later 'burn' the hydrogen as needed to produce electricity again -and get clean water as a 'waste' product.

 

lamorpa

Distinguished
Apr 30, 2008
1,195
0
19,280
0
[citation][nom]freggo[/nom]You combine a solar power station with some form of energy storage of course.Can be anything from...[/citation]
Do you forget about the environment load the system you propose would create from development, manufacture, transport, installation, maintenance, obsolescence, and disposal/recycling? It's not necessarily less than current energy production methods.
 

HeadScratcher7

Distinguished
Jun 17, 2009
29
0
18,530
0
For those that still think nuclear is the solution, remember that global warming isn't just about the greenhouse gases we put in the air but also about the heat we put into the ground and water - and nuclear outputs 4x as much heat as other power generation processing (can't remember where I read that.) Besides, there are plenty of ways to store energy: better batteries, separate water, pump water up hill, gravel filled silos heated/cooled with argon gas, glass/steel structures that soak up heat and produce artificial thermal winds, etc.
Solar, wind, geothermal, and tidal forces are everywhere - we just have to figure out how to use them better. I once heard that there is enough geothermal energy in California to power the ENTIRE state and yet its almost entirely unused - likely due to the influence of oil and energy producing companies.
 

lamorpa

Distinguished
Apr 30, 2008
1,195
0
19,280
0
[citation][nom]HeadScratcher7[/nom]For those that still think nuclear is the solution, remember that global warming isn't just about the greenhouse gases we put in the air but also about the heat we put into the ground and water...[/citation]
and make sure to forget the development, construction, maintenance, environmental disruption, etc. of these '0 energy' facilities (and storage facilities) is huge.

Oh, and by the way, you heard wrong about the nuclear heat output and the CA geothermal energy. Both statements are nonsense.
 
Interesting article and quite a variety of comments. I wonder what motivation and incentives would speed up research and development of all alternative fuels. I certainly hope it is not running out of fossil fuels.
 

Bloob

Distinguished
Feb 8, 2012
632
0
18,980
0
[citation][nom]freggo[/nom]You combine a solar power station with some form of energy storage of course.Can be anything from batteries to molten salt to water reservoirs etc.Personally I'd use excess electricity to take humidity from the air, split it into Hydrogen/Oxygen and store the hydrogen. You can then later 'burn' the hydrogen as needed to produce electricity again -and get clean water as a 'waste' product.[/citation]
You'd lose 50% of the energy when splitting water, not to mention it's gathering, pumbing, and the usually low efficiency of the solar panels themselves. Even so I am pro solar; as long as it becomes widespread enough, there'll be less problems with cloudy skies. That said, I am pro nuclear as well, as a reliable and efficient supporting structure is always needed.
 

Houndsteeth

Distinguished
Jul 14, 2006
512
3
19,015
19
Actually, if they can make it cheap enough that it can be embedded in roofing material and not significantly increase the cost (say, about an additional 10-15%), then I could see a bright future, especially in states like Texas, New Mexico and Arizona, where sunny days are extremely plentiful.

And these PVCs don't have to supply the whole amount of electricity needed by the house. Even 50% of the energy use would be enough to provide relief to most grids, especially in hot summer months when air conditioning uses the most energy. The good news is on those days when you need AC the most, the sun is pumping out a lot of energy to the solar cells, too.
 

rosen380

Distinguished
Mar 17, 2011
422
0
18,780
0
"my thoughts exactly, It would be great to have cheap panels, but unless we can make them near 20% efficient then it would take too much surface area to power the average home."

But what if your options were low efficiency panels that can provide 20% of your needs and cost $2000 installed yourself vs more efficient panels that provide 100% of the power you need but cost $25k.

Figuring 4% increases in energy costs, $200 per month current costs and static use, I come up with the break-even being just under 4 years for the cheap system versus over almost nine years for the expensive system. Given the assumptions I made, the two cross paths at about 10 years, so if you expect to replace the system before then, you are probably better off with the cheap one. If you are using the system for over a decade, then go expensive.

though there is also the value of having the difference invested- That $23K you didn't spend up front, invested, making only 2% would push the break-even for the two systems to 12 years.
 

palladin9479

Distinguished
Moderator
Jul 26, 2008
3,242
0
20,860
45
Some pretty erroneous assumptions by people watching far too much TV. Solar / Wind are not "the future", they can't provide anywhere near enough power to make a dent in our consumption, a consumption that will only go up. That's not saying their bad, because their not. They make the most sense when you can get them for "free", like rooftops on houses and turbines on hill tops. In those situations your not giving up anything significant and thus their energy gain can be used to supplement energy usage. Also their both extremely inadequate to base load, work for peak or swing if stored but you can forget base load.

For long term base load power the only options are nuclear and geo-thermal. Contrary to what the greens will say, nukes are actually extremely environmentally friendly. Biggest hurdle is getting away from Gen I / II PWR / BWR / LWBR design's and moving onto Gen IV MSR / LFTRs. ALL our news today, every scrap of "bad" info is from the old Gen I designs. The environmentalists have been so successful in shutting down nuke designs that China and other countries are actually ahead of the USA in reactor technology. Go figure China will have safer fission plants then the USA soon.

Geo-thermal would be awesome, horizontal drilling has made it easier but we're not quite at the point where their cheap enough to use. Once we can drill and build a heat exchanger at 10km down then Geo-thermal can take off.

And of course you have the holy grail of power, Nuclear Fusion. There have been several design's being testing and worked on, one I like to follow is the poly-well concept of using electrostatics to do the confinement. Plenty of fusion fuel in the dirt under everyone's feet.
 

lamorpa

Distinguished
Apr 30, 2008
1,195
0
19,280
0
[citation][nom]palladin9479[/nom]...That's not saying their bad, because their not.[/citation]

Their what? Did you mean, "That's not saying their bad [cost to power ratio is a problem], because their [ratio is] not [so bad]"?

That's not saying they're bad.
 

palladin9479

Distinguished
Moderator
Jul 26, 2008
3,242
0
20,860
45


Your thinking too one dimensionally. Power to Cost ratio is the smaller of the number used to figure out the viability of a power source. Opportunity cost must also be taken into account, especially when your talking about that much space being used.

I clarified that with the next sentence, which you might not of read.

They make the most sense when you can get them for "free", like rooftops on houses and turbines on hill tops
In situations where there is little opportunity cost a cost-efficient solar / wind solution makes sense. It won't provide for all power but it will reduce the power being used. Space is the big cost behind solar / wind, it requires a ridiculously large amount of space to implement any meaningful amounts of either, that space could be used for other things. Also creating those "green" power sources requires clear cutting, flattening and destroying the natural habitat of anything living near them. Their no where near being "environmentally friendly".

Honestly, the most "green" power source is nuclear once you take size / environmental impact into consideration. It would take thousands of wind and solar farms to equal the power output of a single medium Gen I / II nuke plant. A Gen III / IV creates even more power and an even smaller environmental impact due to on-site fuel reprocessing, they don't need long term waste storage.
 

HeadScratcher7

Distinguished
Jun 17, 2009
29
0
18,530
0
@lamorpa
I like this article from the Oklahoma Observer, which states that both burning fossil fuels and nuclear contribute to global warming.
http://www.okobserver.net/2010/07/21/nuclear-energy-causes-global-warming/
Whether you're breaking down chemical fuels to release energy or busting atoms, they both contribute to thermal pollution - and that heat doesn't go away except for the small amount radiated into space.
So Geothermal, Tidal, Wind, and Solar are definitely the way to go as the energy is already there whether we produce power from it or not. Making it more feasible and viable is just a matter of applying more technology and resources to improving conversion efficiency.

And although I like the idea of fusion reactors, they would have the same problems with thermal pollution. Perhaps humanity needs to consider potential solutions for radiating more of this waste energy off into space. I suppose adding more sulphur dioxide to the atmosphere has the potential to reflect more of the sun's energy away to balance things out, but would also play havoc with solar power generation -not to mention all the other unknown side-effects.

And I did a little research and your right. California produces about 3000 Gwh from geothermal resources and could probably develop another 2k to 10k. Either way this is a tiny fraction of the annual (2011) 285,000 Gwh the state consumes. Geez, that's a big number!

By the way, I HATE nuclear energy. Until the world finds away to properly recycle or dispose of the radioactive waste products, they have no business using it. Storing it on-site is NOT a solution - as the recent crisis in Japan demonstrates - you can't plan for every natural disaster.
 

palladin9479

Distinguished
Moderator
Jul 26, 2008
3,242
0
20,860
45
By the way, I HATE nuclear energy. Until the world finds away to properly recycle or dispose of the radioactive waste products, they have no business using it. Storing it on-site is NOT a solution - as the recent crisis in Japan demonstrates - you can't plan for every natural disaster.
You need to go get caught up to speed on modern nukes, and get your facts straight.

Japan wasn't storing it "on site", they were in the process of shutting down very old Generation I reactors due to age / safety issues. To shut them down you need to remove their fuel rods and cool them in a big pool of water until they can be safety moved to permanent storage. Funny thing is ... it was the reactors that hadn't had their rods removed that were the problems, the empty reactors and fuel ponds were fine. One of the ponds cracked and they had to do a quick repair and eventually transfer the material, but that wasn't the big problem.

Next is that Gen IV MSR / LFTR's do not "store on site" there is no storage required. They do on site reprocessing of their fuel. Most older reactors use a big pool of water with the fuel material submerged and excited until it starts fissioning. The neutrons transfer their energy into the water which cause's it to heat up and eventually turn into steam / turbine. This was the type of reactor used at the Japan incident, it's a VERY VERY OLD design and has some glaring safety issues. MSR / LFTR's have different design's but the core concept is that the Uranium fuel is dissolved into a salt compound that has been heated until it's a liquid. The material inside the salt is excited until it starts fissioning, the salt acts as the moderator (what the water did for early design's). The salt is pumped in a big circle with cooling lines full of water running through it, the water is heated and travels to another set of heat exchangers, there it heats a second water cycle that turns the turbines. Due to this there is no radioactive water getting near a steam turbine. Now the salt doesn't sit there, as the fuel is spent the salt is pumped into the adjacent reprocessing building where new fuel is mixed into the salt which cause's the old fuel to be recycled again (very short / simple explanation for a very long / complex process). The reprocessed fuel is then sent back into the reactor. It's a big cycle with the fuel constantly being reprocessed until all Uranium has been depleted, which should happen once every decade or three.

There are two big differences between the older and newer designs. First is fuel consumption. Older designs' rely on graphite fuel rods that contain fuel pellets (enriched and regular uranium mixed together). Regular uranium can not sustain a fission reaction on it's own, it's too slow. You need unstable enriched uranium mixed in with it to act as a starter. Once that enriched uranium is depleted the regular uranium can not longer sustain a reaction and is left over as fuel ash. You can't add too much enriched uranium or you risk creating a mixing that explodes on it's own. This leaves engineers with a problem, you get lots of unused uranium that you can't burn and must be kept as nuclear waste for long periods of time, you end up only burning about 1~2% of the burnable fuel. With a Gen IV MSR / LFTR the fuel is dissolved in a salt, thus once it's consumed it's enriched uranium you can just add more at the on-site reprocessing facility, this reduces the amount of unburned uranium ash by about 10~100x. Instead of burning 1~2% of the usable material you end up burning 95%+ of it. This also has the side effect of next to no waste being created, there is no unspent uranium ash inside radioactive graphics fuel rods that needs to be stored. You just keep reprocessing it until it's all been burned, then add a fresh batch of salt in while the old salt gets reprocessed at another facility.

Second difference is in the safety mechanisms. Older Gen I / II reactors use water as their moderator, water that gets very hot and is under lots of pressure. This creates the need to actively cool the water during a reactor emergency, otherwise the water gets so hot that it explodes in steam explosion. That's bad, very bad, it would release radioactive material into the atmosphere. The guys at Japan were able to avoid that from happening, but only barely. In a MSR / LFTR the salt is incapable of exploding, and if it cools it becomes inert and no reaction can happen. To guarantee this those reactors are designed with a freeze plug at the bottom of the reaction chamber that must be cryogenicly cooled. If the plug isn't cooled then it melts which released the salt into a boron laced chamber under the reactor where it cools and becomes inert and safe to handle. This concept is known as "passively safe", a safety mechanism that doesn't require active power to maintain.

Anyhow there is so much that people need to learn to understand the discussion on nukes. Otherwise their just flapping their lips / fingers and expelling hot air.
 
Status
Not open for further replies.

ASK THE COMMUNITY

TRENDING THREADS