Hi James, You should consider one of our SWH-1 complete solar kits with our 50 gallon solar tank with single heat exchanger and 4.5 kW electric element. This system would be connected to your existing 100 gallon tank and with one collector this would provide you with solar energy when the sun or daylight is available and give you lots of storage capacity. Depended on the amount of heat loss you may have enough solar storage capacity to maintain temperature at night time requires circulating pump. On cloudy days or at night time the 4.5 kW electric element would maintain your required temperature. If you require more information please contact me by e-mail or telephone directly from information below.
Thanks
Alan Anderson
Northern Lights Solar Solutions
#20 305 McKay Avenue
Winnipeg, MB R2G 0N5
Canada
1-800-317-9054 ext. 226
e-mail [email protected]
www.nlsolarheating.com
www.solartubs.com