Travel to the island of Islay (off the west coast of Scotland) and head to the tiny village of Portnahaven. From there, walk north along the coast for half an hour or so and look out for the Islay LIMPET, the world's first commercial wave power device connected to the United Kingdom's National Grid.
It's not a "tour" (it's unmanned) but it's fascinating. While you're on Islay, you can also enjoy whisky, wildlife and being in one of the most beautiful places on the planet.
It looks like this (photo I took when I was there earlier in the year) https://www.instagram.com/p/BD1Ao-1IaXi/
Details: https://en.wikipedia.org/wiki/Islay_LIMPET
It's not a "tour" (it's unmanned) but it's fascinating. While you're on Islay, you can also enjoy whisky, wildlife and being in one of the most beautiful places on the planet.