As mentioned in the introduction, I discounted using 110v very early in the process due to the proximity of water. The led me to the conclusion that low voltage was the ideal solution.

I initially explored using postcaps with their own self-contained batteries. The only way this might be able to work was to use individual solar panels on each cap. I didn't like this idea as each postcap could have a different amount of sun each day, meaning different brightness levels or runtime (especially as the battery ages) and each postcap could detect "night" at a different time of day. This would lead to a disjointed experience in a situation where you'd expect the lighting to be a single unit.

This led me to realize that the power needed to be centrally controlled and by this virtue could also be generated and stored en masse, providing improvements in efficiency. I decided that I would use 12v as the native voltage allowing to use readily available solar panels and storage batteries. It also allows me to minimize the number of conversions, the majority of charge controllers take in the solar power, and outputs a voltage suitable to charge a lead acid battery. 12v sealed lead acid batteries are readily available from various sources, and by choosing 12v lighting, the battery can supply the lights directly. The only conversions that I need to perform are for the controllers, but again, as these are low power, the currents and losses involved are very low.

By using a central energy store, all lights will be provided with the same voltage, so as the battery discharges and the lights dim in response, they will all dim at the same rate, providing the consistency within the project.