And yet some more energy from seawater:Waves power sea water desalination plant :: Water
And some more ideas that combine most of the above: Science turns sun, surf into green energy - Environment - smh.com.au
No offense, but having enough energy on a all/almost all water planet that's being colonized by a space-faring civilization in the far-flung future, using 'green' technology that's already being developed today, would probably be a non-issue. And within a century, the colonists would have all the energy they need to rapidly replenish the ozone layer. And a lot of the mechanical technology behind these things is not very expensive. A waterworld colony with SPS style energy tech as back-up could be a techno-paradise that could become the intergalactic Silicone Valley, where new tech is being designed thanks to the overabundance of easy to maintain energy resources. Which could also be a reason why outside forces would want to take over Pharos IV. It could also be easy to get funding for the development of the colony, IF proper diplomatic protocols are followed (role-playing opportunity). The only real cost would be due to the remoteness of the colony, but, again, good diplomacy would overcome those costs.
It could also be a great place for scientist all over the galaxy, sector, or whatever, to study terraforming and implement new world building theories (with possible catastrophic consequences).
I realize that the costs of this stuff was already covered in this thread, but the components necessary to create the sustainable energy would be the very first things the colonists would bring with them. Once the colony has an economic foothold, then they can really bring out the "big guns". However, implementing these technologies vs. people and things that don't want them to be implemented could create some very interesting role playing situations.
Also, I strongly recommend studying the concerns for living in "high frontier" space colonies, as those would be the same as the colonies on a planet that has hardly any ozone layer (people having to live indoors all the time).
I discussed this stuff on other forums, so I hope I'm not being redundant on this one.:-) And I suspect you had many of these ideas already in mind.