Posted: 2/15/2003 12:03:41 PM EDT
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Some friends and I were talking about why solar energy is not the common source for power in America. I mean think about it, every single sattelite, shuttle, space station is at least partly solar powered. Why not our homes and businesses? It's fairly clean, eventually you're going to have to replace capacitors or batteries whatever you use to store energy for periods where there is no sunlight. It's not going to dry up, and IF it does, were dead anyway what will we need power for. You can't tax the sun that's why. Is it a conspiracy of the power companies and the government to keep billions in tax money coming in, jobs etc.? Is it that simple? Do I need to take off the hat? |
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It is a lot more difficult to put solar collectors on a car. Most things that NASA put solar cells on are huge pieces of work. Right now solar cells are just too damn expensive to use for most applications. If the future, if solar power is used, cars will most likely be indirectly fueled by the sun. That is, our main power plants will be solar and you will plug your car in. Food for thought: If we were able to store all of the sun's energy that hits the Earth in a day, it would take 21 days to collect enough energy equal that in all of our natural resources combined. That is petroleum, natural gas, coal etc. I think hydrogen power is quite possibly going to be the next big thing. As long as GM doesn't get their way and get this Hy-wire crap mass produced. Toyota and BMW (and I am sure a few others) are working on putting hydrogen power in normal looking autos that people would actually want to be seen driving. The biggest problem with hydrogen is that we might need to use hydrogen to get more hydrogen. If you can make solar to be utilized with hydrogen power, you will be one rich mofo. |
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Because even in sunny California electric power is too cheap. For about $10,000 you can take yourself off the powergrid. Solar panels, inverter, deep cycle batteries (that require replacement) and a control panel. My payoff would come after about 60,000 kilowatts of power useage ... or about 10 years of power use. Solar pannels about 3 feet by 18 inches produce 90 watts .... I would need a few dozen of them. One of the most interesting new products I've seen are roof shingles that have solar cells built in to them. That would save the thousand or so feet of real estate that you'd need to give up to the unslightly panels. For emergency use a gasoline power generator works well enough for short terms. I would eventually like to get 200-300 watts worth of cells to provide enough power to run some of the lighting in my home. |
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Yep get the T-F-B off. expense to benefit ratios aren't as good with solar. Plus the require maint, or replacement, $$$$$$$$, not to mention the initial install into your home electrical system. Of course weather, snow, rain, clouds etc will keep them from producing energy, no to metion night time. On top of that most "home" installations don't produce enough energy to power much. Plus the panels are ugly, and in the subdivision that I live in they are not allowed. |
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Several reasons: 1. Energy density: Only so many watts/square foot from the sun falls on the earth, even when it is directly overhead on a cloudless day. And remember, that's the [i]maximum[/i] input. Further, that input varies with latitude, cloud conditions, and time of day. 2. Conversion efficiency (A): The best solar cells available today only convert a small amount of solar energy into electricity. 3. Cost: The most efficient solar cells are (surprise!) the most expensive. 4. Conversion efficiency (B): Because solar cells only work when direct sunlight is on them, and the output varies with solar intensity, they must be used to charge batteries so that the batteries can absorb energy when it's being provided in excess of demand, and supply energy when the solar cells can't keep up with demand. There is energy lost as heat when you charge a battery (for example 1.3kW into the battery, but you can only recover say 1kW out of the battery.) And again, batteries are not cheap. Plus the batteries have a limited life expectancy. You've got to maintain them and replace them on a $cheduled ba$i$. 5. Conversion efficiency (C): Solar cells produce low-voltage DC power. By connecting them in series, you can get higher voltages, but it's still DC. Unfortunately almost all of our personal, business, and industrial equipment is designed to run on AC power, so you've got to convert the DC into AC through a solid-state device called an inverter. There's efficiency loss there too, and the inverter isn't cheap either. So, solar represents a pretty expensive, not too dependable source of not a whole lot of energy. It fits in places where it is difficult to impossible to run power lines, and where the total kilowatt demand is not too high, and/or where putting in a solar-cell "farm" isn't objectionable (tops of mountains, out in East Bumfvckistan, etc.) I think Paul is right that fuel cells hold the most promise currently (especially in portable energy sources,) though I do wish we'd get over our phobia of nuclear power and do a "space race" program on fusion power. An all-out effort to engineer a functional thermonuclear fusion plant could solve a lot of our energy problems. |
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Paul, no flame - I would be interested to see where you got the idea that fuel cells run off water. One of the by products is water (depending on the fuel source). You could conceivably break water down by electroysis with solar power, then recombine them for electrical power for even lower efficiency. There are a few homes in the midwest set up with natural gas and propane fueled fuel cells to run the entire house off the grid. The power unit is about the size of a refrigerator. Coleman has a unit fueled by hydrogen that is aimed at the home and backup generation market, but it only puts out about 1 kW, so I don't know what use it will be. I guess we have to start somewhere. There is a fair bit of movement in the power industry to implement fuel cells in autos, homes, and businesses, effectively taking all of them off grid for consumption purposes. [url]http://science.howstuffworks.com/fuel-cell1.htm[/url] |
| [size=3]Electricity produced by the solar panel doesn't come from the sun. It comes from the materials manufactured into the panel. The sun is the catalyst. This is so much a common misconception that I rank it up there with the misconception that the 2nd amendment doesn't apply to the people.[/size=3] |
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Probably a better bet would be wind power, requires less space, but then you have the same eco freaks who complain about 'fossil' fuels start complaining about noise pollution and the poor birdies who run into your windmill. Oil & gas are cheaper now. It will take a lot of things to change before it switches around. And we're in no danger of running out any time soon. (I just can't wait for the 'oil comes from dead dinosaurs' fairy tale to be killed once and for all). |
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All the answers and necessary equipment may be found here: [url]www.backwoodssolar.com[/url] I have purchased a lot of stuff from them and they are great people. I don't know if they still stock it, but they had a multifuel hot water heater that would run on kerosene, propane, wood, coal, etc. It could also be set up to run as a still, which means you could make fuel from bio-sources if you really had to. The catalogue is full of useful stuff. |
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stator Sunlight is not a catalyst in the classic definition of a chemical reaction. In the case of solar cells, photons from the sun are used to knock elctrons loose from a semi-conductor, hence providing a source of free electrons to move through a conductor. Sunlight provides the input energy for conversion to electricity. A catalyst is used to cause or stimulate a chemical reaction [u]without being changed itself[/u] by the reaction. A semi-conductor solar cell absorbs part of the sunlight's photons, [u]changing[/]them into electrons and electron hole pairs. It's changed - it's not a catalyst. |
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As everyone else has said, solar energy isn't very practical for powering your home because of the expense of the cells and the batteries and other electronics. Sigh... not fuel cells again. I don't know where people get this stuff. Here's how it works: A fuel cell takes in pure hydrogen from a tank and oxygen from the air and combines them to make water plus electricity. All well and good, but the problem is that people somehow get the idea that pure hydrogen is cheap and plentiful when it just isn't. All hydrogen on Earth is bonded with other elements, and breaking those bonds requires the same amount of energy that you get in the fuel cell. There is some pure hydrogen in space, and in the unlikely event that you figure out a way to gather it and bring it back to earth, you will be a rich man. It's only really practical in a few situations. For example, spacecraft use hydrogen fuel cells for power because they don't emit any gases that might contaminate their limited air supply and they produce water that the crew can drink. I still think that the most promising energy source for the future is Fusion power. To my knowledge, we have fusion reactors now, but we haven't figured out how to get energy from them. To summarize: Capitalism works, and the most efficient energy sources are the ones being used right now. If a more efficient energy source it discovered, then it will be used. |
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Quoted: I still think that the most promising energy source for the future is Fusion power. To my knowledge, we have fusion reactors now, but we haven't figured out how to get energy from them. The problem with fusion is sustaining a reaction, not with extraction. To summarize: Capitalism works, and the most efficient energy sources are the ones being used right now. If a more efficient energy source it discovered, then it will be used. Well, yes and no. Capitalism tends to produce better stuff over time, but sometimes a transition from a presently operating yet cumbersome and less efficient system can prohibitively painful. Case in point: The UAW vs robotic assembly. US auto manufacturers had to engineer a "crisis of quality" leading to lost sales to overseas competition starting in the late 70s so they could justify gutting their workforce in order to put robots on the assembly lines and strewmline their processes with regards to numbers of workers needed. There are other examples. If you want them ask. Some fuel cells can extract hydrogen from MeOH or fossil fuels using catalysts. They are a developing tech that may supplant present methods. Here is a pretty nifty link: [url]www.fuelcells.org[/url] |
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Having grown up in the southern CA desert and having talked to guys working at places like the wind farms around Tehachapi and the solar plant at Kramer Junction, I can say that the big problem with both of them is that they don't scale worth a shit. Powering your home with wind or sun power is doable so long as you are willing to make some sacrifices. Powering a town or even a neighborhood with either one simply gets too expensive. You've got to buy a lot of hardware to start and then you;ve got to perform maintenance on all that hardware once it's in use. Plus, they both require lots of land area and they are both dependent on weather conditions in order to work. |
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I have been looking into this for the last year, and the next house I buy, I will put in Solar and Wind Power with a generator backup. Should be no more than $7500 or so. I won't buy the packages, I have been shopping all around and the 100-125watt panels are starting to come down in price. If I can find what I really want for land, I will also do hydro. In addition have 1000 gallons of propane never letting it drop below 750 gallons. We could be pretty self sustaining for a year if necessary. The only way to do it would be to roll the cost's into the purchase price of the house. |
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Quoted: Some friends and I were talking about why solar energy is not the common source for power in America... Direct solar to electric conversion is a good way of providing a little electricity off-grid -- and that's all. The reason we don't have solar cells providing electricity for homes, cars, industry, etc. is that IT TAKES MORE ENERGY TO MAKE THE DAMN CELLS IN THE FIRST PLACE THAN YOU'LL EVER GET BACK FROM LETTING THEM SIT OUT IN THE SUNLIGHT! The most careful estimate I've seen for energy payback time was over four years, and that was for starting with silicon scrap from integrated circuit manufacturing, and assuming southwestern US insolation; my guess is you have to at least double that payback time for starting from more basic raw materials. So the solar cells that Society replaces our power plants with had better last for at least 8-10 years of hard duty on your rooftop, or else we're WASTING ENERGY making them in the first place. Centralized solar-thermal-electric power stations, like the LUX facility near Barstow, CA, are a more plausible but large and complicated approach. |
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http://www.methanol.org/fuelcell/ http://www.wired.com/news/technology/0,1282,49717,00.html http://www.methanex.com/fuelcells/ Above are links for fuel cells that run on methanol. It seems to me that it would be easier/ cheaper to make methanol than it would to make hydrogen. |
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Ahh wind power. But what happens when the wind doesn't blow? Solar power, hmm, and use all those horrible lead acid batteries to store power, those things are bad for the environment. Nuke and hydro are the way to go. Here's a question, when we all drive electric vehicles (not hybrids), where is all the electricity gonna come from???? You think Calif will be able to add 100% more load to their system? HAHAHAHA TXLEWIS |
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Quoted: [url]http://www.methanol.org/fuelcell/[/url] [url]http://www.wired.com/news/technology/0,1282,49717,00.html[/url] [url]http://www.methanex.com/fuelcells/[/url] Above are links for fuel cells that run on methanol. It seems to me that it would be easier/ cheaper to make methanol than it would to make hydrogen. |
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Quick comment on backwoodssolar: "Owners Steve and Elizabeth both are Quakers, vegetarians, Peace Advocates, and licensed helicopter pilots. They ask that the equipment sold here not be used for any purpose that harms or exploits conscious life-forms, either human or individuals of other species. Caring is the greatest thing." Personally, I care enough about animals to realize it is good to shoot them and eat them. |
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From what I've read of solar power, it is only cost effective if you pay $0.11 or more per Kwh. At that rate your investment can be payed for in savings on your monthly power bill. Where I live in the Pacific Northwest power goes for about $0.05 per Kwh, even after the big rate hike of a few years ago. If they can reduce the price of solar cells and increase their efficiency enough they will start to replace the power grid, but until then it's just not cost effective. |
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When my wife and I build our home starting next year we want to go partial solar with a generator back-up. I want the major power eaters to be solar fed, heat, AC, and fridge. Lights will be on the grid. I just bought a GE generator adapter panel, this lets me hard wire a gas generator into the house system to power up to 7 fuzed sections as needed. SorryOciffer |
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I put a pretty fair amount of investigation into this. For a long time, I was convinced solar power was nice, but not really doable. Then I changed my mind. Here is why: First, there is little doubt that, without financial incentives, solar power takes a long time to pay off the costs of installation. I figured somewhere between 10 and 15 years, and I live in sunny Southern California. But . . . California has a plan that pays for 45 percent of the cost up front. Then, the Feds give you a ten percent tax credit for solar installations, and the state gives you a 15 percent tax credit. In short, they wind up paying for about 70 percent of the total cost. If you finance the other 30 percent with a mortgage on your house, you are left with a mortgage payment (for that amount) that is less than what you would have paid for the electricity. It is (more or less) an immediate profit. Of course, that's assuming a fair number of things that may be unique to where I live (fairly high utility rates, for one). YMMV. But, take a look at the incentives being offered, and consider taking out a mortgage to pay for it, and then compare your mortgage payment against your light bill. I also looked at wind power. I have a fairly constant wind in my area so it is probably one of the few places where wind power would be cost-effective. Doing the calculations, I figured that wind power would definitely produce a profit for me in my situation. The trouble was that the lowest point of rotation of the blades had to be at least ten feet above any surrounding buildings to properly catch the air flow. That meant the tower had to be at least thirty or forty feet high. In addition, it requires routine servicing which means someone has to climb that tower every so often and oil the bearings, clean out the dirt, etc. I didn't want to do that myself, and hiring someone to do it might significantly increase the long-term costs. I abandoned that idea, even before the neighbors objected to a huge windmill in their midst. |
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Quoted: I put a pretty fair amount of investigation into this. For a long time, I was convinced solar power was nice, but not really doable. Then I changed my mind. Here is why: First, there is little doubt that, without financial incentives, solar power takes a long time to pay off the costs of installation. I figured somewhere between 10 and 15 years, and I live in sunny Southern California. But . . . California has a plan that pays for 45 percent of the cost up front. Then, the Feds give you a ten percent tax credit for solar installations, and the state gives you a 15 percent tax credit. In short, they wind up paying for about 70 percent of the total cost. If you finance the other 30 percent with a mortgage on your house, you are left with a mortgage payment (for that amount) that is less than what you would have paid for the electricity. It is (more or less) an immediate profit. Of course, that's assuming a fair number of things that may be unique to where I live (fairly high utility rates, for one). YMMV. But, take a look at the incentives being offered, and consider taking out a mortgage to pay for it, and then compare your mortgage payment against your light bill. In some places solar makes sense. That was one of them, but I think your example ignored the cost of scheduled replacement of the batteries, and the cost of replacing the inverter, should it fail. (It's a piece of power electronics - trust me, it will eventually fail.) |
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Dave A hit it. Clouds and night make solar power impractical on the surface of the earth. But there are orbits in space where solar power satellites can be set up. The problem with them has been getting power back down to earth. Orignally when the idea of SPS's was first conceived in the 70's they wanted to beam the power down with microwaves. The explosion of consumer and vheicular computers and the hysteria over EM radiation from just powerlines and cell phones causing cancer means that this choice would now be as popular as nuclear power. However, research into building space elevators has brought up the possibility that a cable could be lowered from a geosnycronus satellite, and it could be the downlink for a solar power satelite farm. |
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I would like to have my system to have an absolute minimum of maintenance. My wife and I use next to no heat at night, even during winter as we both sleep best when cooler. With the house at 70 degrees at 5pm it cools down to about 50 during the night, when we get up we crank the heat on. It is all on how you mange your power I think to make solar viable. You can engineer it to use minimum batteries or none at all BUT you will need minimum power from the grid. Any problems come up with my plan? SorryOciffer |
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Quoted: [size=3]Electricity produced by the solar panel doesn't come from the sun. It comes from the materials manufactured into the panel. The sun is the catalyst. This is so much a common misconception that I rank it up there with the misconception that the 2nd amendment doesn't apply to the people.[/size=3] "Negative" With your belief, the Conservation of Energy Laws would be violated unless the solar panel became a consumable energy resource. You must account for all the energies of the system; the solar cell is much like a turbine generator it is a tool to convert energy from one form to another. Like the generator, windmill, etc. the solar cell(s) has its defined inefficiency. Photons contain various amounts of energy depending on the different wavelengths of the electromagnetic spectrum. This energy level (quantized) determines what happens when photons strikes photovoltaic cells, where they will either be absorbed, reflected or pass through. Some of the absorbed photons generate electricity, some generate heat, and some never even reach the external circuit. The electrons in a semiconductor material live in a range of defined energy levels, known as bands. The conduction band is partially filled with electrons, creating a negative charge. The valence band has holes or areas where electrons are missing (positive charge). In the absence of light, the positive and negative charges balance each other out. But when light energy in the form of protons strikes the semiconductor material, electrons are dislodged and the equilibrium is offset. This causes electrons to move down an external circuit in the form of light-generated electricity. Solar cells are very expensive and inefficient (~15%). The efficiency may not be a big deal since sunlight is free. However, in order to get a usable amount of electrical energy, you need a large array of cells (which are expensive). The energy (from the sun) is there........The Earth receives as much energy from sunlight in 20 days as is believed to be stored in the Earth’s entire reserves of coal, oil and natural gas I made a SHTF solar energy pack consisting of a 20W array, two independent 12V deep cycle wet cell packs, a active charge controller circuit, and a 200W inverter. The 20W Siemens’s panel was $250. I have over $400 invested in the whole system. Not a very cost effective energy source. One 37Ahr energy source will power a 100W load for 4 hrs continuous. It takes this same wet cell all day to recharge with the small 20W solar panel. To correctly scale my system (8hrs run and 8 hrs recharge time), I need a 50W panel. The 50W panel was out of my budget!. I designed this to be portable. The battery and electronics fit into a 50cal ammo can. The math is easy and fun. Volts, Joules, and Coulombs. |
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Quoted: [url]http://www.methanol.org/fuelcell/ [url]http://www.wired.com/news/technology/0,1282,49717,00.html[/url] [url]http://www.methanex.com/fuelcells/[/url] Above are links for fuel cells that run on methanol. It seems to me that it would be easier/ cheaper to make methanol than it would to make hydrogen. Thermostat of links positively adjusted..... Scott |
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Quoted: [red]Ahh wind power. But what happens when the wind doesn't blow?[/red] Solar power, hmm, and use all those horrible lead acid batteries to store power, those things are bad for the environment. Nuke and hydro are the way to go. Here's a question, when we all drive electric vehicles (not hybrids), where is all the electricity gonna come from???? You think Calif will be able to add 100% more load to their system? HAHAHAHA TXLEWIS Those funky looking windmills with the vertical curved blades turn in the slightest breeze..... Scott |
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Quoted: In some places solar makes sense. That was one of them, but I think your example ignored the cost of scheduled replacement of the batteries, and the cost of replacing the inverter, should it fail. (It's a piece of power electronics - trust me, it will eventually fail.) I assumed no batteries. I am on a well, with a three horsepower electric pump driving it. The peak power required would make batteries far too expensive, even not considering the replacement (30,000 or so is what I estimated for my situation -- 21,000 of which would be paid by the government in one form or another). Batteries are only required if you are going to run your whole house off the thing when there is no other power. That would be nice, but it isn't practical in my case, where power outages are few and far between. That's the same reason I didn't buy a $15,000 generator (which is what would be required) to provide power in rare outages. I may wish I had it if we have another earthquake, but we have only had one of those that caused any major interruption in my lifetime, and that was only for a few days. My goal was simply to reduce the ongoing costs, as I am in the computer trade, with lots of systems running and I tend to consume a lot of electricity on an ongoing basis. I just wanted to get the bill down. As for the converters, they don't break often enough and don't cost enough that it would have affected the basic equations. |
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The idea should not be to completely take yourself off the power grid, but rather bring all sources of energy together and mix them up to be practically useful. You have your house and garage shingles covered with solar panels and a few windmills, collectively they produce X volts at X watts. You have a box that takes the energy generated by these devices and the power company fills in the rest. On a hot sunny day all that power is going toward running the air conditioner, but on a nice sunny day you would have that power being stores into batteries to be used at a later time. As others have pointed out, the technology needs to come down in price before it becomes a practical relality. But at the same time we should make much more effort to utilitize free sources of energy and stop using up finite oil resources just to make Bush's friends richer. |