Solar Panel Performance vs Sun Elevation

Which is why I'm tilted in winter. What's NOCT?

NOCT is a standard used for solar panel specifications.

"The Nominal Operating Cell Temperature (NOCT) is defined as the temperature reached by open circuited cells in a module under the conditions as listed below: Irradiance on cell surface = 800 W/m2. Air Temperature = 20°C. Wind Velocity = 1 m/s. Mounting = open back side."

Hi CA,

Thanks for the graphs.

I find that elevation really helps when making solar power. My highest amperage for my pair of 45 watt solar panels happened in November, after running the furnace a lot and watching TV the night before, so the battery was kinda low. Snow on the roof also helped, and it was around 25F.

We where in Phelan CA, at around 4,500' elevation, the panels tilted to the south, snow on the roof reflecting to the panels.

Recently San Diego installed a few dozen acres of solar panels near El Centro CA. That was a BIG mistake, as they could have located them 30 miles closer to San Diego at 3,500' elevation in Boluvard, at a higher elevation where it is 30F cooler, and closer to the sun. I measured the watts per square meter in Boluvard on January 9 at noon, and again in Lakeside CA 45 miles away and 45 minutes later at 800' elevation. I was reading 1,080 watts per square meter at 3,500' and only 965 watts per square meter at 800' elevation.

Also for those thinking of putting a solar panel on their dash, when I measured the solar W/Meter on the dash or inside the window on the way down the hill, I was only getting around 500W/meter on the dash, and 650 with the window closed. Roll it down and I was over 980 W/M.

Thanks for the graph. The elevation at Grand Junction is 4,800' according to google.maps.com and then look at terrain, it gives the elevation.

This is why Colorado is such a great state to have solar panels! They are also far enough inland that they do not get the 'lake effect' moisture like along the coast.

Thanks, it helps to have some additional information about solar panels. Now that the cost is so low, it is really easy to just keep installing more panels.

Have fun camping!

Fred.

Rule of thumb: angle panels per your latitude position.

Watching the output on the single panel keeping the bank happy over the winter has been mildly disappointing but a good education in what I have to look forward too.

Colorado is a great state to have solar except for the twin monsoons in the summer and daily clouds at noon in between. Sunny days in the winter tend to be cloud free but you need it with the lower sun and shorter hours. That said, going up from 5000 ft to 10,000 ft nets me a amp to a amp and a half as does being in sub freezing temperatures. So a 250w panel that peaks at 18.5a at 5000 ft in the summer should get close to peaking out the eco-w at altitude in the winter.

Golden_HVAC wrote:
and closer to the sun.

3500' is 0.00000000712 of the distance to the sun. Does that really make a difference? Isn't it more likely the temperature difference, and less atmosphere between panels and the sun? (not simply distance)

for here at least it's thinner air and low humidity. Cooler temps? It gets hot at elevation too.

2oldman wrote:

Golden_HVAC wrote:
and closer to the sun.

3500' is 0.00000000712 of the distance to the sun. Does that really make a difference? Isn't it more likely the temperature difference, and less atmosphere between panels and the sun? (not simply distance)

And less pollution at higher elevations. I'm skeptical that being higher on a mountain in and of itself makes any difference including Pikes Peak at 14,114'.

There is no question that tilting yields more solar panel power and tracking even more. But for $200 (now $170) I added another panel and don't have any reason to go on the roof. :B

But per another thread I also don't have that "guy magnet". :S