I don't speak for the HOA, but I have served as Architecture Committee Chair. First, check your covenants. There are some variations by filing, so find the right one.
The covenants generally forbid things on the roof that cause a visual impact - things like antennas and swamp coolers. Past HOA policy has been to ask "can this be seen from the street?" There may be laws regarding solar. For example, the FCC allows "reasonable antennas" on the roof, but also says the HOA can require visual impact mitigation.
It's always a good idea to check with the neighbors who would be visually impacted. Be aware of the PV's reflection - a neighbor installed a solar water heater that lit up my kitchen (heat!) in the summer. It was not pleasant.