M
[email protected]
- Jan 1, 1970
- 0
A story in the _Christian Science Monitor_ titled "Low-cost lamps
brighten the future of rural India" (
http://www.csmonitor.com/2006/0103/p01s02-wosc.html ) describes a
solar-powered white LED lamp used to light homes in rural areas
without electricity. The only components it mentions are a solar
panel and the lamp itself, and says the entire assembly costs US $55.
It would be interesting to know what's in these assemblies. I'd think
it could be as simple as a solar panel, a diode, a gel-cell battery, a
switch, a resistor, and (presumably more than one) LED. A supercapacitor
might not have the wear-out problems of the battery, but it probably
costs more. It would also probably require a DC-DC converter to give
a relatively constant voltage output, which happens "for free" with a
battery.
I wonder why these assemblies are not using CF. I suspect it may be the
cost of getting "custom" CF lamps that work from low-voltage DC, or of
including an inverter to turn low-voltage DC into higher-voltage AC for
the lamps. http://www.lutw.org/Technicalinfo.html suggests that it
might be a lamp-life and durability issue.
Also, I was under the impression that presently available solar cells
cannot return as much electrical energy over their lifetime as it takes
to manufacture them. This may not matter compared to the cost of
bringing the electrical grid to remote locations, but it should factor
into the effciency calculations that are being made.
Matt Roberds
brighten the future of rural India" (
http://www.csmonitor.com/2006/0103/p01s02-wosc.html ) describes a
solar-powered white LED lamp used to light homes in rural areas
without electricity. The only components it mentions are a solar
panel and the lamp itself, and says the entire assembly costs US $55.
It would be interesting to know what's in these assemblies. I'd think
it could be as simple as a solar panel, a diode, a gel-cell battery, a
switch, a resistor, and (presumably more than one) LED. A supercapacitor
might not have the wear-out problems of the battery, but it probably
costs more. It would also probably require a DC-DC converter to give
a relatively constant voltage output, which happens "for free" with a
battery.
I wonder why these assemblies are not using CF. I suspect it may be the
cost of getting "custom" CF lamps that work from low-voltage DC, or of
including an inverter to turn low-voltage DC into higher-voltage AC for
the lamps. http://www.lutw.org/Technicalinfo.html suggests that it
might be a lamp-life and durability issue.
Also, I was under the impression that presently available solar cells
cannot return as much electrical energy over their lifetime as it takes
to manufacture them. This may not matter compared to the cost of
bringing the electrical grid to remote locations, but it should factor
into the effciency calculations that are being made.
Matt Roberds