Solar power for shed - Page 3

 

Ron Rosenfeld wrote:


I doubt it. Those 8 or 15 hours aren't at max insolation.

Here's the important data.
https://glfc.cfsnet.nfis.org/mapserver/pv/municip.php?n&19&NEK=e

And we need ....
Mean daily global insolation (kWh/m2) which we can see from the last chart is
2.5 kWh /m2 of sunlight daily averaged over a whole year or 1.7kWh/m2 in
December

A 54W solar panel is likely to be about 0.3m2 at typical modern efficiencies of
15%. The winter insolation output on that panel will therefore be 0.3m2 * 1.7kWh
* 15% which amounts to 76.5 Wh per day in winter.

Therefore it would run a 26W fitting for about 3 hours daily neglecting other
losses.

Simple facts and figures ! Solar is NOT the way for high latitudes. It's even
questionable at the equator.

Graham

  On Wed, 13 Aug 2008 21:50:09 +0100, Eeyore


I used the same data source.

Not that it is at all relevant to the adviseability of the system, but I
think you may be looking at the wrong column.

The column that shows 2.5 is for a solar panel tilted at 90°.  In other
words, on a building wall.

I was using the column for the panel tilted at latitude, which gives a
yearly insolation of 3.4.

I derated the panel to 90% so used 3.4*54*.9*365/1000 = 60 kWh/yr. Actually
the simulations I ran showed a bit less.  Still, as I wrote, slightly more
than that required by the one bulb on an "annual" basis.

For the light bulb run time, I used a generated table of sunrise-sunset
times from an astronomic program to obtain the yearly consumption of 51 kWh
per year.

As you point out, this system won't work year round in NF.  So the OP is
either going to have to spend more money, or revise his usage estimates.

As to whether or where solar PV might or might not be practical, I believe
the relevant consideration is the cost of alternatives, and not necessarily
the location.  Examining only personal economic motives, I would be looking
at cost of grid extension; availability of solar/wind/hydro resources; cost
of fossil fuel sources and generators; maintenance; etc.

Even in my location, if my electrical usage were, for example, 5 KWh/day
during the worst month, solar would be less expensive than the
alternatives, including grid extension.
--ron

 

Ron Rosenfeld wrote:


You can actually get 12V DC CFLs these days but the power tools are another
matter.

Graham

 
Why not just use solar tubes for light?


-=   http://www.flickr.com/photos/rosepetal236/    =-

 
I'd bet there are many brands but here is one:
http://www.solatube.com/homeowner/productcatalog.php


-=   http://www.flickr.com/photos/rosepetal236/    =-