A bit off-thread, but wondering: what is people's long-term satisfaction level with solar vents?
When I bought my boat it had two, in both main overhead hatches. They were ugly and no longer worked. I replaced the NiCd batteries in them, still nothing. I read up on them, there was no longer any support from the manufacturer, and folks had gone to great lengths refurbishing them with quite a dose of MacGyver. I ended up replacing the Lewmar hatch lids at a cost of about $900. Now I have beautiful, clear hatch lids! So, my long-term satisfaction with them is very low.
I would be more interested in servos that would keep my Dorade cowls pointed into the wind! (We're on a mooring and the direction of the boat is determined by the current in the river, not the wind.)