This is would be fairly inexpensive to do. DC heating elements are < $40 and used panels can be had for ~0.20$ a watt or less. You'd wire the PV panels direct

This is would be fairly inexpensive to do. DC heating elements are < $40 and used panels can be had for ~0.20$ a watt or less. You'd wire the PV panels directly to the heating element. (Of course you'd have to size your element to match the volts/amps of your panels)