I'd like to suggest that consideration be given to using LED SMD Strip lights for lighting the Pavilion. Here is a an example product:
https://smile.amazon.com/Flexible-Waterproof-Holiday-Outdoor-Decoration/dp/B075R4X1XL/ref=sr_1_1?keywords=led+strip+light+5050+white&qid=1576944043&sr=8-1(I'm just using that product listing as an example. I generally buy my LEDs strips from a China Ebay vendor at about 50%-60% of the Amazon price. One just has to wait longer for delivery)
These are a 5 meter (16.4 ft) strip of individual LEDs mounted to a flexible carrier strip. They are available in both 12 volt DC and 24 volt DC. I am using the 24 volt version as "closet" lamps in my house, and also as general lighting in my shop/barn. I came across them initially as a solution to the National Electrical Code restrictions/specifications on closet lighting fixtures (Code requirements are tighter for closets as flammable fabrics are more likely to be in close proximity to light fixtures in closets). Since then I like them enough that I am using them in my shop as replacements for florescent fixtures when the ballast fails.
In terms of the Pavilion, if the decision is made to use solar panels & battery to provide lighting, the 12 volt LED strips would work well. Since they are natively 12 volt DC, no inverter would be needed provide 120VAC from the batteries - just run the LED strips directly off the battery.
If a generator is used, some generators can directly output 12VDC, so that would be an easy setup. But alternatively, like in my shop and house, 12VDC or 24VDC power supplies (converting from 120VAC) are very suitable.
The LED strips have somewhat of an advantage over LED in a conventional "bulb" form in that while heat is still generated by each LED, the heat is spread out over the full 5 meters of the strip. One problem that "bulb" type LEDs have is heat dispersion. If the bulb gets too hot - it dies. Strips do not have that problem.
These strips come with a sticky back foam on the backside, and that mounting system has worked well in my house. In my closets all the strips are mounted on the walls (rather than the closet ceiling) and none of them has come loose in the 4 years since installation. However, in my barn the strips were initially stuck to the underside of [dead] flourescent fixtures, and the sticky foam mounts are not reliable in that orientation. My later iterations are to apply the strips to a 1x2 or 1x3 board using a "hot glue gun" then mount the boards to the ceiling, and that is easily done and the strips stay "glued" well.
Since the strips are 5 meters long, it would be convenient to have 5 meter boards to apply the strips to, but 5 meter 1x2s or 1x3 or 1x4s are in short supply in my area. A reasonable alternative is to use 1x2x8' boards and just cut off the excess LED strip. The strips are cuttable every 6 LEDs in the 24 volt version and every 3 LEDs in the 12 volt version. That is why you see two parallel strips in my photos below - I just make the strip length suit the board I am using.
A couple of photos (these are "thumbnails", so click image to see larger):
A photo of 'lit' dual strips in my recent barn side shed expansion.
A closeup showing the LEDS and a couple of 'clear' retainers held in place with screws. (There are also some bigger screws visible mounting the LED board to the ceiling.)
Where I am, carpenter bees are an issue with any exposed wood, so everything, even treated lumber gets a coat of paint to deter the carpenter bees. Since the Pavilion trusses are not painted, and did not appear to be targeted by carpenter bees (maybe not an issue in Maine?) it seems to me that the [unpainted] 1x2 LED boards could be mounted directly to the underside of the trusses (oriented parallel to the trusses). The LED strips are very unobtrusive when not lit.
Update: I recently found that "double" strips are available. This is two rows of LEDs mounted on a common strip. I have switched to buying these as they are faster to install for a given amount of light.
