Forum Discussion

HiTech's avatar
HiTech
Explorer
Dec 14, 2012

Measuring solar yield approaching winter solstice

I need to get a temporary setup on the RV roof to measure solar yield around the winter solstice. How deeply discharged will I need to get my 85 Ah battery so that it allows pretty full production ...
HiTech's avatar
HiTech
Explorer
Dec 15, 2012
red31 wrote:
I believe your panel is rated at ~4 amps @ 16.5v, to me that means at at radiation of 1000 watts/ meter^2 at some temp, a standard test. So if you use 3000 watts/day * 4 amp = 12.

Page 9 has the data for Houston, 2.9 Max, 2.2-2.9, 2.5 average.
http://rredc.nrel.gov/solar/pubs/redbook/PDFs/TX.PDF


Exactly the Unisolar charts show the standard test at 1000 but also has curves for 800 on down. I have never seen 4 amps into a battery yet but orientation is flat and it has only been fall sun.

Jim

About Technical Issues

Having RV issues? Connect with others who have been in your shoes.24,188 PostsLatest Activity: Jan 17, 2025