I live on Long Island, NY .
I installed 2- 4x10 solar panels (80sqft) with a 120 gallon tank for DHW.
during the summer (on sunny days) it does about 95% of my needs for a family of 4
During the fall it does about 40%
from nov to mar it does close to nothing.
I have a meter that keeps track of time run on my oil burner and took montly readings.
during the summer I still used 30 gallons/month, I think heat lost up the chimeny and rainny/ cloudy days.
If you are gonig to install a solar system, I wuld say install 3- 4x8 panels to a 120 gallon tank.
Install a drain back system which is more reliable with fewer problems.
here is a link ti a drain back system:http://tinyurl.com/4nsphf
I don't have a coal boiler yet, but I will soon thanks to the info you guys are sharing ..... Thanks Alot!!!!
The best thing about installing a hot water solar system is once it's installed you are done.
it turns on and off by itself and there are no ashes to dump!!
I estimate the system saves me about 400 gallons of oil a year at $4./gal that is $1600.00
but if you have a coal boiler burning cheap coal I don't think a solar system will save that much.