I've seen solar kits for preheating the radiator water of a park home so the boiler heats less, but not PV panels.
I cant see a problem installing them, but I don't think you would get a FIT payment.
Maybe the construction of the roof cant handle the extra weight?
Also, does the park owner allow such additions? It would be taking income from him if he charges you by a meter.
Can I ask if you use a lot of plug-in heaters?
I've had a lot of experience with static caravan owners saying their 16A supply had tripped. Centrally heated vans with LPG boiler, but they have half a dozen plug in heaters.
"Oh, we never use them" is the normal reply.
The other way you could use that much electric is cultivating plants if you know what I mean.