Hi Bo, Where are you located?  What is square footage of your home or shop? What size is your wood boiler storage tank?Do you run glycol thru the boiler? Is the outdoor boiler used for domestic hot water and space heating is it hydronic heating or radiators Thanks Alan

Thanks for the reply.   We are located in Newland, NC about 3,600 ft in the mountains of western North Carolina.  Heating about 3,500 sq ft of home. The boiler is a central CL-5036 holds 196 gallons of water, 74 sq ft heat transfer area.   I am using a mixture of about 50/50 water and glycol. The wood boiler is used to heat the home in winter. I have two heat pumps (one for downstairs, one upstairs) that I have put radiators in the ductwork and using the blowers on the heatpumps to forced air. Also use the wood boiler for hot water.   Thanks again for any information. I know there is a couple of different types solar panels. The solar tube and the thermal panel. Any advise would be appreciated.   Bo Sluder