Solar Power in the Third World 221
KTS writes: "Over at Wired, there's an interesting article about the use of solar energy by the rural poor in the Dominican Republic. Soluz, Inc., a Massachussetts-based company, has installed thousands of solar panels on an island where most of the rural population is cutoff from the power-grid. Says the article: "Rural communities rely on solar energy for everything from pumping clean water from aquifers to recharging cell phone batteries." According to another article, the Dominican Republic now has "more [solar panels] per capita than anywhere else in the world." After constantly hearing about the misuse of technology, stories like this make you feel good. With solar power, it looks like developing countries can avoid much of the downside that comes with electric power, while reaping the benefits. Zero polution, no overhead lines, and no squandered petroleum (after all, we need the oil for ourselves)."
Re:Economics... (Score:2)
Yes, but a real solar power station won't be based on PV cells. It'll be a concave field, many miles across, filled with mirrors mounted such that they can turn and follow the sun. You can power this bit just by spare heat from sunlight. The mirrors are curved to focus the sunlight on a huge black obelisk in the middle of the field. This obelisk is filled with a network of pipes.
The sun comes out, the mirrors reflect the sunlight to focus on the obelisk and it gets real hot, real quick. Cold water gets pumped in, gets superheated into steam, then drives turbines which generate electricity. The steam then gets routed to run CHP in a hearby town, then cooled and either pumped back in, or vented harmlessly into a river.
That's how to use solar power on an industrial scale, but I don't know if there's anything like this in production yet.
Re:Decentralization is the big win - NOT (Score:2)
Re:Flourescent Lights (Score:2)
Solar Is Expensive (Score:2)
DR Power (Score:2)
Re:Fuel cells, oil and batteries (Score:2)
I sense a bit of confusion on this sub-thread.
Some fuel cells, like the ones on the space shuttle, combine H2 and O2 to generate electricity and water.
Other fuel cells use methane or propane plus O2 to generate electricity.
For hydrogen fuel cells, you have to create and store the hydrogen gas. With other fuel cells that use hydrocarbon fuels directly, that's not necessary.
Re:Not zero-pollution. (Score:2)
On a smaller scale, this can be done with in closed vessels. The height is quite important, however.
Compressed air can be used to store energy in small amounts.
You need to define how much energy you need to store before looking for the optimum solution.
OTOH, this is the physical world. The laws of thermodynamics won't go away. Anything you do will have an environmental cost. Anything. The trick is to carefully choose the least expensive, calculating ALL the costs. That gets quite tricky.
Caution: Now approaching the (technological) singularity.
Your .sig is NOT JEFFERSON!!! (Score:2)
The phrase "From each according to his abilities, to each according to his needs",, which you credit to Jefferson, is usually attributed to Karl Marx as translated from his Critique of the Gotha Program, 1875 (source: Brooks Spencer, 1997). Spencer notes "It is curious that the first [phrase] closely parallels a phrase from Saint-Simon, the second one from Fourier and both, from phrases from Babeuf." I find it interesting that in the consitution of the People's Republic of China this is transmogrified to 'from each according to his ability, to each according to his work.' (source: Article 6, PRC constitution, 1982).
Now, in reality, Marx cribbed this wholesale from a Frenchman who said it in the 1700s. For penance, you may search out the original quote - I couldn't find it on the web anywhere.
NOT JEFFERSON!!! And don't believe most of the Ben Franklin and Adolf Hitler quotes you see on Slashdot either, they are generally fakes.
--Charlie
Re:you must have Pow-wah! (Score:2)
I agree with you on the completely fucked part, though.
Economics, schmeckonomics (Score:2)
Yes, I consider myself to be "green". No, I am not a tree hugging hippy. However, I am getting tired of polluting and reqiring mega-corp to furnish me with whatever it is I need.
Fuel cells require some sort of fuel for them to work - in the case of most of the ones I have seen for home use, that fuel is natural gas. That is all fine and good, but that means I have to pay a utility to get it to me. Last winter natural gas prices shot through the roof here in Missouri.
PV, on the other hand, does not require that. You set it up, do some regular maintenance on it, and for at least the next 30 years those panels are going to be generating power. There are quite a few of the very first panels still pumping out the electrons.
Sure, it is going to take me a hell of a long time to pay off any panels I buy. I don't care. However, when the local grid goes down, who's house it still going to have power? Better still, after some sort of a natural disaster, who is going to still have power when the natural gas lines go kablooie?
PV is getting cheaper and cheaper all the time. The people who are doing all the PV FUD are the politicians who have all the oil company bribes in their back pockets [whitehouse.gov].
Re:"Boring Facts" thread - post away! (Score:2)
Putting solar cells on roofs is a great idea. When we get the right materials technology, paving our streets with it is even better. But that still won't be enough to be engergy self-sufficient.
When we get solar cells with 90% efficiency, it will be real smart to use them. But they still won't replace other sources of power.
Re:"Boring Facts" thread - post away! (Score:2)
Think of your own city or town, and where you would put that much solar cells. I live in Mountain View, California. In order for it to work for us, we would either have to pave over a significant portion of the San Fransisco Bay, or declare war on Palo Alto and take their surface area.
Re:Rest of the world (Score:2)
To a small fish generating 'clean' energy, yes, it sort of seems that way, but it's not. I'm not saying it's bad for all the guerilla power types to feed home-brew juice back into the grid; I support that completely; but it doesn't solve the problem.
Re:Cost of Power (Score:2)
I wonder what the effects of covering 3% of the US landmass with windmills will do to ground weather patterns?
Cost of Power (Score:2)
In our current global economic climate, solar power (and wind power, and every other type of power, except maybe Hydro... but that's only a guess..), is quite a bit more expensive per power unit.
I recall reading some studies showing how we could not simply 'convert' north america to solar/wind power, because there is simply no way to generate the same amount of energy, regardless of cost.
So, in that respect, solar power is much more expensive.
But if you try to use your diesel generator in these countries, first you have to find a supply of diesel... that gets expensive. Solar power is fairly self-sufficient, even though it has a higher initial cost. It just works.
If you factor in environmental costs... solar power is far cheaper. No pollution (other than manufacturing the units, don't forget that...). They have a long, long life cycle.
If you have limited power available,
But money isn't everything. Asking the typical North American society to change it's ways and use a hundred times less power isn't going to happen... but to these people, power is a new thing.
Their society can adapt to use the power they have in the best possible way... let's all hope that 100 years from now they aren't chugging out huge amounts of pollution, but instead have roof material made of solar cells, and perhaps a manufacturing plant leading the world in cell design.
Re:Rest of the world (Score:2)
How exactly do you 'store' power in the power grid? You don't.
Yes, you can run power 'back into the grid' and run your meter backwards... in effect, selling power back to the grid.... and it will most likely get used up somewhere else...
If all the power in the north-american grid isn't at 100% usage, the excess does not get 'stored' anywhere, it just vanishes. Want to do an experiment?
Get your honda generator out, put $10 in gas into it, and fire it up, but don't hook anything up to it (this simulates a generating station).
When it runs out of gas, try to run something off it. Gee, where did all that power go?
You are incorrect, sort of. (Score:2)
However.. with household AC power, it's the 50 or 60 hz cycle *fibrilating the heart* and causing heart attack that kills people, not the actual amount of power. It doesn't take much AC voltage to kill people, only enough to make the signal reach the heart.
In that respect, 220 is more dangerous. That will only cause burns. Short of enough current to burn organs, all you have to fear is some surface burns (that could be bad).
Re:Rest of the world (Score:2)
The problem is that so many 'environmentalists' simply state that we could replace all our power needs with solar/wind, and that to not do so is silly. The fact is, we cannot produce north america's energy needs (or anywhere near it) in this manner.
Obviously, it's entirely possible to live comfortably in a rural home on solar power (provided you are somewhere sunny). But what about building that home? What about the materials needed? What about manufacturing those batteries you use? All of this takes power as well.
Re:sustainable development (Score:2)
How is this different?
Would selling them far cheaper generators and then selling them oil be better?
Environmnental impact. (Score:2)
We could put huge cells covering the desert, say.. in NM, AZ, etc... After all, we aren't gonna build anything there, right?
Hmm. But... that means we'll be blocking the sun from many square miles of desert.. doesn't that have an environmental impact?
Renewable energy (Score:2)
Re:Rest of the world (Score:2)
But even the talk of excess solar energy is a little silly and unecessary. Energy planners don't plan for average usage. The have to plan and build plants for PEAK usage. What's more, there isn't a guy sitting at a meter giving the generator more gas when he sees a spike coming. The generator have to be fired up and ready beforehand (hence the planning).
If every home in the US was covered with solar cells we would STILL need power plants. It's just that the usage spikes would be much lower and possibly reversed (ie, they would not need to produce as much, but they would need to produce more at night when everyones sp went offline).
Re:Solar ponds (Score:2)
Not that I'm against solar power. I quite like the idea, actually. But I've yet to see it as at all economical in my situation. $70,000 for a home setup (I number ISTR from a back issue of Home Power or somesuch) is a tad steep. At even $300/month for electricity, that'll take 20 years to pay itself off. And by that time the system would be way too outdated. I can do better things with $70,000. Even at a 5% rate of return, I could turn it into $185,730, which could buy one whopping nice solar panel system in 2021, even if it _would_ be worth only about $103,834 in today's dollars. Now get that price down by a factor of ten, and I'd snap at the chance, esp. because I myself only use about $30/month, and would thus be putting $270/mo. back into the system and thus making money underneath net metering.
Cost of independence (was:Cost of Power) (Score:2)
Don't forget the value of predictability and self sufficiency. For rich people, our wealth buffers us from the full effects of fluctuations in energy costs. Rural poor folk I know who rely heavily on propane are getting smacked pretty hard now.
Another way of looking at this is -- does Bill Gates need health insurance? Of course not. For the average person, you are essentially paying the insurance company to turn a wildly fluctuating expense into a constant one which is, on average, higher by the overhead and profit the insurance company makes. If you have the resources to cover the fluctuations, you can afford to have expenses and income fluctuate more.
I think poor folk need self sufficiency more than rich folk, who can use their captial to quicdkly adapt to change and buffer themselves from its worst effects.
Re:Warms the heart (Score:2)
Appropriate Technology (Score:2)
One great story is where the "advanced" white man brought a bunch of solar panels to a third world country. The locals found that they worked great as tables but not much else.
Other considerations need to be thought about as well. In some countries, children play a role of water carriers. Go in and start pumping water with solar panels, and you've changed the social aspects of the community. The children must be given some other role to play.
It all sort of reminds me of time travel in the movies, where the person goes back, changes one small thing, and suddenly a chain reaction of events occurs, forever changing history, often for the worse.
Re:displaced polution, not eliminated polution (Score:2)
Although I agree that the right long-term solution is for people to always pay the full cost of their pollution, you should be careful with statements like this. The truth is that none of our power industries have to pay the full cost of construction and operation once environmental effects are taken into account.
In the long term, we should remove subsidies and tax pollution across all industries. But in the short term, it makes sense to subsidize solar at least as much as we do, say, nuclear and coal.
Sigh (Score:2)
The reason I said that you should be careful is that you were making a true statement that could give a false impression, namely that solar is somehow more subsidized or more coddled than other power industries. I agree that all subsidies should be removed eventually, including the hidden subsidy of the ability to pollute. But continuing to subsidize coal and nuclear while pulling the plug on solar's subsidies is foolish and dangerous.
Apparently you're more excited about the "loudly, and often" part; perhaps you should try focusing more on being "carefull".
Fuel cells, oil and batteries (Score:2)
As a matter of fact, that hydrogen has to come from somewhere. We don't find it in nature, so we have to produce it. By using other sources of energy, such as fossil fuels, solar energy or whatever.
Its not will, its money (Score:2)
And, don't discount the fact that electricity usage varies. One of the greatest advantages of the united states is the widespread, electrified infrastructure. Energy use does not tend to increase as much as transform itself. From gas-lamps to the light bulb. From oil-heating to electrical heating. Which is more effecient, a million small coal-fired steam plants running steam turbines in factories, or a few centralized powerplants that run far more effeciently and clean up the pollution emissions.
Our incredibly electrified country os something to be proud of,
Re:Not zero-pollution. (Score:2)
Re:Rest of the world (Score:2)
BTW, local distribution is usually 4300V - 12000V. So those pole mounted transformers would be 4300V to 480V three phase step downs. Medium distances would be 66000V - 230000V and really long distances would be 230KV to 1000KV.
Re:Not zero-pollution. (Score:2)
Not true. It takes from one to several years [ecotopia.com] to break even, depending on the technology, but the claim that they take more energy than they put out is pure FUD.
Also, if you're far enough away from the grid it can actually be cheaper to install a photovoltaic system than to run copper and get on the grid.
The above is the standard repost from the last solar power article. Thanks to Mr. Slippery (tms@spambefuddler-infamous.net) for the real scoopHere here (Score:2)
Re:cost vs benefit (Score:2)
www.homepower.org
They point out the energy payback in in under-5 years based on a German study.
Wind power has a under 3 year payback based on the power used to produce it.
Do you have some links to prove your POV, AC?
Re:Not zero-pollution. (Score:2)
I've been told that solar cells, given their lifespan of 30 years or so (what the article linked said, I believe), a solar cell cannot generate in its lifetime, in full sunlight, more energy than it took to create it in the first place. Now, this may no longer be true, or it may never have been true. I've also been told it's an urban legend. I could figure out how much a given solar cell could generate over that period of time, but I know nothing about how much power every single process needed to make the solar cells takes.
Anyone know if this is truth or fiction?
I've always been partial to wind power, myself -- even if not electric, you can rig up something simple out of wood and fibre to pump water or provide mechanical power. Things that are easier to do are invariably easier and cheaper to bring to the masses.
Re:Economics... (Score:2)
Neither is likely to be cost effective at present electricity prices and construction costs. These are funded as research efforts to gain experience with the technology at full scale. Given present politics it will be very hard to make the change to price electricity high enough to justify this as a power source unless someone finds a way to drop construction costs and operating costs dramatically.
Meanwhile PV and wind both offer cost effective solutions in their individual niches.
Re:Puts things in perspective. (Score:2)
Re:Cost of Power (Score:2)
absolutely not true. In fact, you could do it with just wind if you wanted. Go read this article for more information, the gist is : "To provide 20% of the nation's electricity, only about 0.6% of the land of the lower 48 states would have to be developed with wind turbines. Furthermore, less than 5% of this land would be occupied by wind turbines, electrical equipment, and access roads. Most existing land use, such as farming and ranching, could remain as it is now." So to provide 100%, use 3% of the nations land area, while actually covering .15% such that it cant be used for anything else, like farming. Granted, it would be expensive, but it could be done.
Re:Not zero-pollution. (Score:2)
Also, did you know that the NUCLEAR reactions in the sun create millions of tiny particles that can pass throgh the entire earth, without even slowing down? that these NUCLEAR reaction products have unknown health effects, and it is UNKNOWN whether RADIATION collectors such as solar panels might interact with them, with disastrous result.
you can make anything scary, even neutrinos, the most harmless particles in the universe.
A buddy of mine is involved in this. (Score:2)
Re:Rest of the world (Score:2)
The main argument for 120v is that it is somewhat less fatal to touch accidentally than 220. The major downside is that it obliges larger wiring to avoid voltage drop/transmission loss. This has material/energy costs of its own.
-dB
Re:Rest of the world (Score:2)
Re:Economics... (Score:2)
Solar power has low ongoing costs - no refinery workers to pay, no use of fuel to refine fuel (refineries USE quite a bit on energy), just the costs to make them and some occasional maintenance (you would have that with ANY power source).
Re:Economics... (Score:2)
Hello? Newsflash! gasoline is already over $5 a gallon here in the Netherlands, but i don't see anyone using solar power... Also, the reason the price has risen this much, is that americans are using so much gasoline that they have to import extra from europe, making *our* prices rise due to your excessive demands... think about that when you see someone driving that SUV.
Re:Economics... (Score:2)
A solar panel is also a conversion device, converting solar radiation to electrical power.
And yes, the two are in competition with each other. The Santa Fe Railroad (now Burlington Northern Santa Fe) used to use solar panels to power their remote communications units, but switched to propane powered fuel cells. Why? Lack of sufficient power at night or under cloudy conditions, plus, wind and hail repeatedly damaged their expensive solar panels.
Re: (Score:2)
Re: (Score:2)
Re:Rest of the world (Score:2)
Re:"Boring Facts" thread - post away! (Score:2)
Magius_AR
Cell phones ?? (Score:2)
Cell phones in rural areas that are cut off from the power grid ? :-)
The usual tree hugging comments (Score:2)
http://www.windsun.com
You city dwellers that want to actual help, instead of just verbalize you ignorance can do one of several things.
1. Buy solar panels and a grid tie system to 'help' out the local power company.
2. Buy a bank of lead acid batteries and an inverter and use grid power only during off peak hours and your own juice during peak hours.
3. Don't use electricity during peak hours, period.
4. Shut up, sit back, learn, and do something constructive with your life.
What country developed the technology for solar cells? Who is the leader in MOSFET, IGBT technology? Who for microprocessor technology? Lead acid battery technology? (other batteries just don't cut it for cost and efficiency) In short, what country is slowly making solar technology affordable for everyone? If nothing else, what country should be getting the extra green house gas producing credits for making the solar panels and electronics for the Domincan Republic (not that I believe the green house gas arguments anyway). The free market economy is working people. When we do run out of oil (no time soon) then the price of oil generated electricity will skyrocket....solar panels will be the cheap alternative....peace on earth will break out...the tree huggers will find something else to whine about.
Slightly off topic. The reasons I don't buy the green house gas malarkey:
1) I'm an aero engineer. I've seen the code used to produce these models. When they can start telling me the weather next month, I MIGHT start to believe their 10 year predictions. Yes I know the difference between climate and weather.
2) Islands like Wake Island in the Pacific are only a few feet above sea level. The highest point of the island (actual 3 islands) is 22 feet. A big wave can wash right over the entire island. This island and the Marshal Islands will be some of the first things to go under if the sea level rises. So what happened during the 20th century. Nada, zilch. I've been to some of these islands and have seen them with my own eyes.
What is it with Slashdot and the tree huggers. Is VA an arm of Greenpeace or what? BTW I love trees and consider myself an environmentally friendly guy, but not to the point of a frontal lobotomy.
a very large point is being missed here (Score:2)
Re:Economics... (Score:2)
--
Re:AC/DC (Score:2)
Re:Rest of the world (Score:2)
A lot of industries move to the third world to benefit from looser pollution rules (or lack of pollution rules.) Just because the media hasn't seen fit to tell you this information yet doesn't mean it doesn't exist.
Re:you must have Pow-wah! (Score:2)
Not FUD entirely. Just old data (Score:2)
I have a friend who did the calculations on a common type fo solar cell himself and found that, at least 5 years ago, they did take more energy to make than they were getting out of them. Economy of scale might be a part. But there are different types of solar cells too. The technology may have improved in the last 5 years too.
I would think of it less as FUD and more as outdated info.
Re:Cell Phones Make Sense (Score:2)
That depends on the anticipated subscriber density and on your cost of financing.
In sparsely-populated areas or in cases when it is difficult to secure long-term financing at reasonable rates, wireless is cheaper, yes.
In a dense area, when you can afford to invest for the long term, nothing beats good old fashioned copper. At least so far.
Amerindian FM Radio Station running on solar (Score:2)
My experience in Guyana suggests that the PV side of solar energy is the easy part. The correct setup and, critically, maintenance of the inverters and batteries is where most installations fall down.
My former boss has a lovely setup at his retreat house up the mighty Essequibo River - miles and miles from the nearest road, nevermind power grid. He has 4 panels which track the sun (delivers about 20% more) and the seasons (negligable this close to the equator). Trace/Heart Interface inverter/charge controller and four big deep cycle gel-filled truck batteries. Runs a DC fridge, 12-15 low power flourescents and, on really hot days, a fan.
Oh - 2 laptops too!
3rd world is the future? (Score:2)
Just a thought anyways.
Say "NO!" to tax money for religious groups. [thedaythatcounts.org]
Re:sustainable development (Score:2)
Read
My
Lips
Re:Rest of the world (Score:2)
Re:I've lived in the Dominican Republic (Score:2)
Further rumor - confirm or deny? (Score:2)
- Intermittent power makes it impossible for the poor and lower-middle class people to have appliances we consider basic, such as refrigerators and microwave ovens.
- This forces the people to depend on vendors and shops for perishable foods and cooking fuel.
- The shops and fuel merchants are owned by the wealthy, who get healthy markups.
- Reliable electricity would allow people to buy food less frequently and shop for price, and use electricity for cooking instead of fuel. This would replace high-margin sales by the shops with a few "white goods", further revenue going to the utility operator.
- Accordingly, the wealthy classes do not want reliable electricity as it would cut into their immediate profits.
Is there any truth to this?--
Decentralization is the big win (Score:3)
If you don't have thousands of other paying customers on the same segment as you, you're not going to get great service, and you'd do better to just do it yourself with a solar system or a generator, and solar's just easier at that scale.
tempted myself (Sydney, Australia) (Score:3)
Danny.
Re:Economics... (Score:3)
Fuel cells are not in competition with solar energy, because fuel cells are not an energy source. They are a method for storing energy (like batteries, but better). You still have to generate that energy somehow (and solar is as good a method as any)
Re:Rest of the world (Score:3)
Obviously, you've never been to a city in a third world country. They most definately do have pollution problems: pollution control on cars is far less, heating and light are often generated by burning kerosene, coal, or even animal dung, and forget about sewers and garbage collection. Pollution controls for industry are much less strict if enforced at all. Plus the density of people is usually higher.
Re:Not zero-pollution. (Score:3)
Another important factor is scale. You cannot compare the environmental impact of, say, a wool coat with a polypropylene fleece one, without taking into account the scale of production. To produce a single coat, the cost of the polypro coat is vastly greater, but the marginal effect for each new coat is less, whereas the environmental impact of wool increases at least linearly and possibly faster at very high scales of production. At some point, the marginal impact of the next wool coat may meet or exceed the polypro.
Perhaps an alternative to complicated environmental auditing is simply to internalize the costs of pollution by regulating disposal of wastes and charging a fair price to cart what can be disposed of "away". If the PV cells are indeed manufactered in Massachusetts, then the cells are manufactured under some of the strictest environmental regulation and enforcement in the world. Very likely the environmental costs of PV cells are much more fully accounted for in their price than the costs of fossil fuels.
I sure couldn't tell when I was there (Score:3)
Are you serious??? (Score:3)
They'll be gone by the end of the week.
Re:cost vs benefit (Score:3)
Sorry, I forgot to answer the second part of your question
Let's assume that this 40 watt system will operate at 12 hours a day, and let's derate the output to 40 watts over 8 hours (instead of 12). That gives us 320 watt hours per day of work, or 115 kilowatt hours per 360 sunny days. You will have to reduce that figure depending on the local climate.
Where I live, electricity costs about 9.5 cents per kilowatt hour, so this setup would be worth about $11 per year. Not much of a bargain - for me anyway. (In case you are wondering, I probably get 350 days of full sunshine per year.)
But I don't think MY cost comparison is of any interest to the people in the article. The first few hundred watts are probably the most productive anyway. After that, the watts are probably just "wasted" on entertainment.
Re:"Boring Facts" thread - post away! (Score:3)
---------
Interesting maths there.
You get ~1kW/m^2 of sunlight, so that's 2560000kW of raw sunlight, which at 30% efficiency is:
2560000kW * 0.3 = 768 000kW == 768MW
---------
Point of view from an applied physicist:
Sunlight from the earth is 1.2 kW/m^2 (higher than your estimate). However, 30% efficiency is a pretty big overestimate of how much you can get from a presently economical solar cell. There are solar cells approaching 30%, but these tend to be made out of more exotic materials and are not as easily manufactured.
Starting from an incident flux of 1.2 kW/m2:
Half the time it is night. So averaged over a day gives: 600 W/m2.
But in most places, not every day is sunny. So, hack another half off that: 300 W/m2.
Also, the efficiency of a solar cell is strongly dependent on the angle of incidence of the sunlight. Assuming a low cost installation where the cells aren't pivoting (expensive and prone to break down) to catch the rays gives a loss in available flux. Using a generous a cos^2 depenenced takes us down to: 150 W/m2
(Note: It is probably much worse as the cos^2 only accounts for effective reduction in solar cell cross-section area as the sun rises and sets. For grazing incidence light most of the sunlight will reflect off the solar cell. And yes, exotic solar cells have been designed to reduce this, but this adds to cost and manufacturing difficulty.)
Now, apply a realistic 20% solar cell efficiency: 30 W/m2.
Thus, a typical solar cell can be expected to yield on average (a generous estimate):
30 W/m2.
Of course, this ignores the efficiency of any storage system you might have if you want to make use of the power generated when the sun is not directly overhead on a clear day. So to try to get a more realistic feel, hack off another half to account for efficiency and grazing reflection:
15 W/m2.
So, a square mile array of solar cells could make an average contribution of:
1600 m * 1600 m * 15 W/m2= 38,400,000 W
This is one-twenth the value of the previous poster and a bit closer to the original post, but 38.4 MW can power a fair number of homes.
However, as the previous poster pointed out, in most cities, you could get more bang for your real-estate via other means.
However, when the sun is directly overhead, on a sunny day, you will get a peak performance of roughly 240 W/m2.
Since this is the time when power is most needed anyways, this points to solar cells being used to offset peak power demand when everybody's air conditioning kicks on simultaneously. I don't expect solar cells to be the primary source of power anytime soon except in special situations.
Kevin
Sometimes it's not electricity what you need (Score:3)
Re:cost vs benefit (Score:3)
And what's more, in 'developed' countries, we've already made a huge investment in power stations to supply our mains electricity, plus systems to distribute that power.
So one important comparison has to be that between spending, say $10,000 for a solar facility for a village (still a lot of money in most places on the planet), and $several_million to build gas/coal/nuclear/whatever powered centralised power stations and distribution networks. Which might end up more economical when calculated across an entire country, but has to be done in one fell swoop rather than being achievable piecemeal, village by village, region by region.
And then there's the ongoing cost of fuel, the carbon release or nuclear waste disposal, the moving parts, the high operating costs...
It will cost us a lot of money to convert to solar in the short term, but, as Keynes so nicely put it, in the long term, we're all dead. and it's in the long term that our grandchildren will thank us for having the foresight and wisdom to take a hit today and set the change in motion.
TomV
Re:Rest of the world (Score:3)
Comment removed (Score:3)
Re:Not zero-pollution. (Score:3)
You could always try a flywheel [slashdot.org].
sustainable development (Score:3)
Unless the technology can be maintained with local expertise it is just putting the people in a dependant relationship on more industrialized nations. There is a path that technological development has to go on to empower the people, and sometimes that means that less good technologies have to be used.
I've lived in the Dominican Republic (Score:3)
First off, the electric situation is terrible in that country. This is not just for the remote undeveloped rural regions. In the major metropolitan areas, even the capital city, Santo Domingo, just about everyone who can afford it has their own gas generator. Why? Because the power outages are frequent and of great duration. In the US, if the power goes out frequently, anywhere, (say like California recently) it makes front page news, people are crying out because "We were out of power for 4 HOURS last night!" In DR there are parts of the city where they measure the time the power is ON like that, not where it is off. It's more like "Woo Hoo, we had a full 6 hours of power today!" The solution to this problem for many is gas generators. But these are really expensive to purchase, so it's the middle to upper class (who are vastly outnumbered by the lower class) that are able to buy them. These generators are also very expensive to operate, since gas isn't exactly cheap in the third world (like it is here, he says sarcastically) so most people can't have them or even operate them.
I believe the idea of solar panels to be a blessing for the country. Goodness knows that the government is corrupt, and the ruling class doesn't give a shit about the poor. It's a lack of will and cash that is preventing the outskirts from even being wired, and it's corruption that causes the places that ARE wired to remain dark. Solar panels are a way for the people to power themselves, cheaply. This has to be good.
cost vs benefit (Score:3)
Correction to your figures (Score:3)
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Re:cost vs benefit (Score:4)
Well, first you have the solar cells. Fancy new ones will probably cost $10 per watt, but I have seen perfectly good looking surplus ones for around $4/watt. So you would be looking at about $160 or so for the 40 watts mentioned in this story.
Of course, you aren't just going to nail the solar cells to a tree, so also figure in the cost of a nice frame. Considering that these people don't have a lot of money, I think it would be better to make the frames locally, and save on the labor costs. How does $20 for a plywood and plexiglas frame sound?
We also want some way to store the power. A deep-cycle marine battery is just right for this. Figure maybe $50 for that. The rich imperialist systems also include a charge controller, but our friends might prefer to save the $100 or so and flip a switch when the battery is fully charged. Add maybe $10 for a pair of cheap gauges (volts and amps).
Also figure in the cost of electrical wiring and miscellaneous hardware. I think we could get the cost down to around $250 if our goal is to provide power affordably.
How long will all this last? My guess is that the cells may (may!) last 10 years, the battery as long as five, and the frame maybe a few years. That brings my 10-year estimate to maybe $300 to $400, or up to $40 per year.
Solar power in rural areas... (Score:4)
The big trick with a low input power system like that is the user's energy budget. Here in the states, we're used to having a huge budget for power. But, when you live on battery or generator power, you learn to economize. Folks in rural areas won't have the energy budget we may be used to in an urban area, but any power is better than none, and Solar is often a great solution. One reason many long distance cruisers (sailboats) rely heavily on big batteries and a rack of solar cells...
Re:Not zero-pollution. (Score:4)
Re:"Boring Facts" thread - post away! (Score:4)
Solar ponds (Score:4)
What I learned, however, was that the sun is much better at heating things up than creating electricity. Heat a home, or water for a home, or a greenhouse - at these the sun excels. Also, we're still not very good at converting that energy into electricity. We would have been much farther along 'cept for fucking Ronald Reagan [sonofhans.net] (link's dated, but funny). Bastard killed off solar energy research in the 80s.
Anyway. Solar power is useful, yes, especially in 3rd-world countries where people aren't such energy hogs. But until our technology improves vastly (or we all start using much less energy), solar-generated electricity isn't going to help the 1st world very much.
"We all say so, so it must be true!"
Re:"Boring Facts" thread - post away! (Score:4)
Solar heating hacker (Score:4)
He has many hundreds of usenet posts [villanova.edu], ideas about converting an existing house to 100% solar [villanova.edu], low cost and warm homeless shelters [ibiblio.org], and is conducting solar heating experiments [villanova.edu], all using inexpensive / easily obtainable materials.
If you're interested in solar heating, you should check him out.
solar power initiatives in the US (Score:4)
There is a map of current locations of partnerships in the United States here:
http://www.eren.doe.gov/millionroofs/tally.html [doe.gov]
The main webpage for the program can be found here:
http://www.eren.doe.gov/millionroofs/" [doe.gov]
And here is a list of projects that have already been put into place in the United States related to this program:
http://www.eren.doe.gov/millionroofs/news.html [doe.gov]
bbh
Flourescent Lights (Score:4)
While this may sound crazy, flourescent lights have come a long way and the technology is fairly common and is becoming cheaper everyday.
The cool thing about flourescent bulbs is that they now come in standard "edison" screw type sizes so you don't need to buy those long tubes. On top of this, they are over 80% efficient (only 20% of energy is turned to heat) and last 10,000 hours! [5 - 7 years under average use] Good old incandescent bulbs only last 1,000 hours at most and are only 15% efficient. (85% of the energy goes up as heat.)
Not only is this a boon for 3rd world countries, but it is helpful for 1st world ones with states that have rolling black-outs. :^)
So if you're a Californian trying to get in on the 20/20 deal, you might want to look into getting flourescent lights for your house. Not only do they produce less heat, they consume only 1/5th the electricity.
The best place that I've found to buy flourescent bulbs online is some company called http://www.energyguide.com [energyguide.com] and New Englanders get a $5 discount per bulb making them practically free. So what are you waiting for? Save yourself some money by lowering your electricity bill! (and perhaps avoid rolling blackouts!)
Re:Solar ponds (Score:4)
Personally, I'd much prefer if the prices oil, gas, and nuclear energy would simply reflect the actual cost they impose on society: health costs, defense costs, environmental costs, etc. The real costs of those energy sources are many times as high as what you pay on your bill. Some of that cost, you pay in seemingly unrelated taxes (defense, health care, etc.), others you pay in quality of life, diminished lifespan and health, diminished quality of life, etc.
But since it is wildly unpopular to charge for those traditional energy sources what they actually cost, the second best thing to do is to subsidize the development of alternative energy sources to the point where they are competitive even with the current, distorted prices for oil, gas, and nuclear power.
But one way or another, public health and externalities are two areas that governments are supposed to worry about, even in a completely capitalist system.
Puts things in perspective. (Score:4)
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net metering (Score:5)
Not zero-pollution. (Score:5)
manufacture photovoltaic cells. Just remember
that there are other ways to exploit the sun,
as well (solar ovens, solar heating ranges,
et cetera).
Re:Economics... (Score:5)
1.) Solar cell sales have grown at a CAGR over 15% for the last 15 years. PV production has been running at capacity for over 10 years, despite construction of new PV manufacturing facilities. PV sales are on allocation and have multi-year backlogs.
2.) PV sales are now far more dominated by considerations of cost effective power generation than by considerations of cost effective publicity generation.
3.) US installations of solar cells are very widespread, but are now being installed mostly by people who do not spend money on publicity regarding the installations.
4.) Most installations are cost justified by the cost of installing grid power vs the cost of installing the PV system. For a small data monitoring system (commonly needed for railroads, natural resource sites, etc.) the cost of the PV system is usually less than the cost of installing one utility pole. So you see PV power even in fairly urban areas. For larger installations, the construction cost tradeoff is usually something like 1-2 miles from power line to power need. Then PV makes sense. There are lots of sites like these, but they are all miles from the nearest road and get little publicity.
Re:Not zero-pollution. (Score:5)
I only skimmed this before posting, but Free Electric Power from the Sun ? Is it oversold? [countryplans.com] appears to address this question.
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Economics... (Score:5)
In the Dominican Republic, a small island isolated from the immense power grids of places like the USA and Europe, with limited ability and resources to produce its own power, it's perfectly feasible (even with the high cost of replacing solar panels in the long run). However, we have a huge infrastructure for pumping, transporting, and burning petroleum.
High efficiency, low-maintenance solar cells are a good direction in which to spend research $$, but I think it'll take a major shift in economics to make this work--especially with competing fuel sources like fuel cells on the very-near horizon.
"Boring Facts" thread - post away! (Score:5)
The best solar cells generally have about 30% efficiency, relative to the total flux of sunlight hitting the earth in the given area. To output 100 MW requires about 1 square mile of cells - that's enough power for about 18,000 people (Americans, that is... or about a million Dominicans).