Africa’s Rural Poor Begin Harnessing the Sun
nytimes.com
nytimes.com
They mention de-forestation in the article. I do worry that if our next "green" energy source isn't cheaper than oil/coal then the third world will ignore the cleaner alternative.
I mean, it's not like they can freely use coal and gasoline in their huts. It is also more efficient to burn the coal & gas in a plant.
On cellphone towers in the middle of nowhere with no wirelines linking them, a solar panel makes a lot of sense, even if it never recovers as much power as it cost to build. Or on a satellite. Or, apparently, on a shack in rural Africa.
I agree Africa probably could do better with natural gas, oil, hydro, or coal central plants for now, vs. big solar plants, but a combination of cheap big grid power sources and decentralized renewables seems like the best solution. Building out a grid in rural areas isn't really cost effective.
Thermoelectrical Generator Kit - ThermoGenKit - http://www.youtube.com/watch?v=8mFyiYh94YE
Seebeck Effect - http://www.metacafe.com/watch/1129994/seebeck_effect/
Thermo-Electric Generators - http://www.douglas-self.com/MUSEUM/POWER/thermoelectric/ther...
BMW Heat-Harnessing Technology - http://www.sacarfan.co.za/2009/10/bmw-heat-harnessing-techno...
http://www.innovationsforeveryone.com/Comment_Innovation.asp...
http://en.wikipedia.org/wiki/Thermoelectric_effect
Using both heat and cold you can create a small amount of electricity from these units. I have seen something like this used in a camp. They would place one end of a metal rod into a fire and the other in a bucket of water. Then they could create enough electricity, using some type of thermoelectric circuit, to 'trickle charge' a cell phone or GPS.
If the sun is out for say, 12 hours a day, that means it can power my light for 240 minutes. But turning my crank for 10 minutes would power the light for 300 minutes.
Is solar really efficient at all, because wouldn't getting a hand-turned generator get more electricity than waiting for the sun?
If you are expand your solar cell to a square meter then you will make more power than an "in shape" cyclist can sustain for an hour (200 watts).
Rules of thumb:
• 1 square meter in full noontime sun gets about 1000 watts of sunlight.
• Solar panels are about 20% efficient, so 200 watts per square meter at noon.
• Total sun delivered during the day is equivalent to 4 noon hours in the summer, 2 noon hours in the winter.
2. Even a small solar panel can power your water pump/weather station/radio repeater when you're ten miles away and don't have the time to spend all day walking ther to spend a minute turning its crank.
3. Solar panels break down less than hand-turned generators. They don't have bearings or windings or gears. If you keep replacing the batteries, your flashlight will ber a usable solar-powered flashlight much longer than it is a usable dynamo-powered flashlight. (The "shake light" design, with a magnet sliding back and forth in a tube through a coil, might be an exception there.)
4. Solar panels keep working even without being fed more rice. Human labor does not produce energy, regardless of what you may have heard in The Matrix; it merely converts it quite inefficiently from chemical energy into mechanical energy.
5. An athlete working his hardest might consume 10 000 calories per day in food, but can only convert some 2000 of those calories into work. If your Lance-Armstrong-level athlete is turning a crank 12 hours a day and eating 10 000 calories, he's producing 200 watts during that time, 100 watts averaged over the 24 hours. Three square meters of solar panel can do the same. Six square meters can do twice as much. And the solar panels won't drop dead of exhaustion after a month.
(Supposedly Lance averaged 5200 kcal/day during the Tour de France with a peak power output of 1000W: http://www.wired.com/wired/archive/12.07/armstrong.html --- but presumably ate more on uphill days than on level days.)
I live in an African country and solar panels have one huge disadvantage. Solar panels are often used now to power boreholes (usually fully submersible pumps which have become fairly cheap and easy to install, compared to so called "mono-pumps" of the old days) and pumps near rivers that are far from grid electricity. It is also used to power electric "energizers" for electric fences.
The problem is that solar panels keep getting stolen. It is something that is fairly valuable that should be outside. I can just imagine the amount of theft that will go on when people have solar panels on the roofs of their homes/shacks.
Also, the article failed to mention the real problem with using candles and fire for lighting - frequent fires.
I imagine that for applications in town, the theft problem will be less. If you have ten or twenty houses clustered together, you can probably leave one rifle home with one of the women in case someone tries to steal the solar panels. I mean, that's the same problem as someone trying to steal a motor scooter or whatever, right?
I lived in rural South Africa (not anymore though).
> I mean, that's the same problem as someone trying to steal a motor scooter or whatever, right?
What is funny for me is that motorcycles aren't as popular in the African countries that I have been (e.g. China or India). But yeah, things that is not inside the home is easily stolen. Things like car batteries or solar panels are extremely popular items to steal.
> What kind of pumps do people use now?
In the old days they used mono-pumps (where the motor was above ground and connected with rods).
Nowadays the pump is in one sealed unit that is connected with plastic piping and electricity. Two people can install a pump in less than half a day and everything is light. The price of pumps also dropped.
Could it be because they're too easy to steal, and there's less theft in China and India?
Leon Trotsky, of all people, had a theory of "uneven and combined development" http://en.wikipedia.org/wiki/Uneven_and_combined_development
Essentially, this says an under-developed area has an opportunity to leapfrog the most develop areas, producing an entire new paradigm of development.
By the time African villages directly contact the West, they may have an entirely different form of capitalism we may be emulating...
Instead of reading HN you should watch Fox News. No quotes of stupid ppl like Lenin and Trotsky there...
The same applies to Trotsky, if you read that wiki page you will see Trotsky's idea is actually pretty damn good.
He is obviously expressing surprise at who it was. Just because the person may have not been a role model or the brightest person in general, however, does not mean all of their ideas must be thrown out. If you disregarded the ideas of anyone who believed or did something you disagreed with, you´d only have yourself to look at.
If the objective is to keep your TV and radio on during the blackouts, I think a car battery is probably a better choice than a solar panel.
Or I could be wrong, of course.
They are often portrayed as "poor as beyond poor" because many economies are much less money-based than in the West.
Not to say that they're wealthy but if you combine food being less expensive with a lot of subsistence agriculture, a person can have a very low income without being utterly miserable. IE, "Surviving on pennies a day" is a lot easier in Kenya than San Francisco.