You can probably (I haven't verified this) omit separate radiators and just use the back of the solar panels. Effectively you're describing mounting each H200 to the back of a 4 m^2 solar array at which point I suspect the equilibrium temperature will fall within an acceptable range. In fact the H200 and electricity are both entirely irrelevant here - the core question is what the equilibrium temperature of a black planar surface is at a given distance from the sun.