On 1/28/2012 9:40 AM, daviddschool wrote:
On Jan 28, 12:31 pm, Sjouke Burrys@b wrote:
wrote in news:e35a378a-671d-473e-
:
I am thinking green here. I have recently seen a couple of 15W solar
panels (15 X 2) on sale at Canadian Tire for $99.00. If I have those
hooked up to an electric generator, could I :
1) Trickle charge the generator
2) Have enough power to run some lamps, computers etc
Any suggestions would be great. Thanks
1:no.(you cannot charge a generator, you might try a battery)
2:no.
Ok, how about this:
http://www.canadiantire.ca/AST/brows....jsp?locale=en
This is a battery like you suggested. Could this be trickled charged
to run things constantly?
And thank you for the quick reply
I don't know a lot about batteries for renewable energy, but that
battery looks
suspicious.
First it's $300. You need to find a better battery source.
It's rated at 1 amp for 100 hours. Typically, batteries are specified
for 20
hour discharge. I'd look at the curves before buying one.
You shouldn't have to pay $3/watt for solar panels.
Don't buy solar stuff from a tire store.
Do some math. Add up all the loads you want to run for how long
and calculate the total number of amp hours per day at 12V.
You need at least that much solar power accumulated per day.
Problem is that solar panels are rated for power output at noon
on a sunny summer day in the lower latitudes.
Do some googling and you'll find maps of average insolation history at
various locations.
You'll find that, for most of us, The total solar power you're gonna
get to charge your batteries on a cloudy winter day approaches zero.
You need a LOT bigger array and a lot more batteries than you might
think to do anything useful. Typically, you want more power when the
sun ain't shining.
Bottom line is that solar power is not even close to cost effective,
or green, for most of us.
I can think of two cases where solar power is beneficial to the end user...
1) where power is not available at all or costs way too much to acquire.
If you have a traffic sign with lights on it, the cost of the solar array
and batteries is often WAY less than the cost to dig up a street to
route power from a source right across the street 100 feet away.
2) where you can get someone else to pay for it...government subsidies.
For the record, I'm NOT interested in paying for YOUR solar system.
It makes almost no sense to pay $100 for panels and $300 for a battery
plus another $$ for the inverter to get, maybe 50 watt hours on a winter
day. This assumes that you're in Canada and not Arizona.
Even if your system is 100% efficient and you lived in a place that
was never cloudy, you're gonna get a couple of hundred watt hours/day.
You're gonna be into this sytem $4-500 by the time you buy the wire
and brackets and inverter and connectors and nuts and bolts and ....
If you save 2.5 cents/day in electricity, the payback period is
50000/2.5 is over 50 years. If you count the cost of investing the
money, the payback is...never. And that assumes your battery lasts
50 years.
Stated another way, the carbon footprint of you driving to two stores to
pick up the battery and panels is probably bigger than all the carbon
you'll ever save by using them. And that ignores all the carbon
costs of making the stuff in the first place, shipping it around the world
and disposing of it when it's done.
To recap.
Not cost effective.
Not green.
Are we green yet?