Posted by Martin Trautmann on May 2, 2006, 11:17 am
are there any PV measurements around?
I'd like to get a better idea concerning optimum cell orientation for
I'd like to see e.g. a weekly average of energy vs. day of time. This
would require multiple measurements a day, including date and time
Additional info: cell area, latitude, orientation, inclination.
A good extra info would be the outside or cell temperature.
I'd like to gest some visualisation converning the best orientation,
which does not only take a very basic average assumption (mostly based
on 'orientation = south', 'inclination = latitude + x'), but better
assumptions concerning the real application.
Martin - Freiburg, Germany
Posted by dold on May 2, 2006, 4:46 pm
There is a tool for sites in the US based on actual observations from
http://solardat.uoregon.edu/SoftwareTools.html has some tools that show the
sun path across the sky.
http://www.gcstudio.com/suncalc.html provides a listing of apparent solar
positions for a particular day.
has some live reporting viewable online.
Clarence A Dold - Hidden Valley Lake, CA, USA GPS: 38.8,-122.5
Posted by Martin Trautmann on May 2, 2006, 5:57 pm
On Tue, 2 May 2006 16:46:38 +0000 (UTC), dold@XReXXPVXme.usenet.us.com wrote:
Thanks. The year is selected as 'meteorologically typical', but every
month may take a different of those years.
That's very close to my needs. But it's a summary only, while I look
for raw measurement values.
Posted by R.H. Allen on May 3, 2006, 2:26 pm
Martin Trautmann wrote:
It uses the TMY2 database (where TMY stands for "typical meterological
year"), which is a statistical representation of 30 years of hourly
measurements boiled down to represent a single typical year. It doesn't
draw directly from the observed data; rather, it attempts to produce
results similar to what you would get if you repeated the simulation 30
times, each time with a different year's observed data, then averaged it
for a single year. Being an hourly database, TMY2's creators also took
pains to accurately represent the variations and extremes of a typical
year, but I have no idea how they did it or how accurate they were.
However, TMY2 is used by most PV system simulation software for U.S.
The full 30 years of data used to create TMY2 are available at
http://rredc.nrel.gov . If you've got a way to plug it in to your
simulator of choice, you can use those raw measurement values.