Before the days of the steamship, ocean going transportation used totally renewable energy. It had to, there wasn't anything else. Sailing ships were a big deal. World trade started with sailing ships, and it worked great for many years.
Then steam ships came along. They were complicated, dangerous, and used vast amounts of coal. Countries needed "coaling stations," all over the world. It took huge amounts of political and military effort to establish the necessary infrastructure.
Why did they bother? Power, that's why. Steam ships were faster. On the sea, there is the fastest and everybody else. In military doctrine, he who gets there first with the most wins. Steam ships got there first.
Steam also put the final nail in the coffin of the old style pirates. Pirates didn't have coaling stations. When everyone had to use the wind, pirates and the military were on pretty equal footing. A sailing ship could be repaired and provisioned from many different places. They could go as far as they wanted on the wind. Navies didn't have a technological advantage over pirates.
These days pirates don't cross oceans. They are pretty much a coastal phenomena. Once their fuel is half gone, they'd better turn back to home port, or become stranded. Marinas aren't in the business of refueling pirate craft.
Now if we did have ships that ran on renewable power, then maybe the far faring pirate would return. On the other hand, transport ships are slowing down.
Clipper ships used to make better time than today's container ships. Maybe there's hope for pirates yet. However, they need a new kind of ship. Picture a ship that normally travels by sail. It can get far out in the ocean yet not have to worry about running out of fuel. Since container ships are traveling slow enough that a good sailing ship can catch them, the pirate sailer can ease up on it.
Of course, an old fashioned sailboat won't work. Once the container ship realizes the sailing ship's intent is hostile, they can say the heck with conservation and kick the engines into high gear. Old fashioned sailboats would be left behind in a puff of petrochemical smoke.
New pirates need a scaled up version of this: http://www.macgregor26.com/
It's a boat built for sail, but can fire up a big engine and go up on plane, speeding right along. The valuable and limited fuel would only be used for zeroing in on the kill -and perhaps while trying to escape pursuit. Changes the game, doesn't it?
Who knows, with advances in solar electric panels and electricity storage, maybe a ship could have a powerful electric motor for high speed propulsion. The pirate ship sails slowly along, while solar panels charge up a massive bank of ultra capacitors (or other advanced battery system) That energy gets used up in a massive burst when the ship needs to go really fast for short distances. With renewable energy, this cycle could be repeated many times. A "green" pirate ship could stay out on the open ocean for a long long time.
Something to think about.
I don't know why I just reinvented piracy, but there it is.
Everlasting Covenant (a link)
39 minutes ago