Solar charging using or not using a dummy (dump) load
http://www.backwoodssolar.com/products/diversion-loads

"If you use a windmill that does not have its own charge control, or use hydroelectric generating, a diversion control must be used, since those generators can be damaged if their charge is not absorbed in the batteries at all times".

Solar panels will sit happily with no load, while other kinds of generator will not.