That's a tricky/misleading comparison to make since most of that oil energy is lost as waste heat, possibly 2/3rds of it. You really only want to compare the actual energy that makes it through to achieving some stated goal like moving a car or heating a home.

Its been a while since I worked in the field but I'm pretty sure the main sources of electrical power in Scotland are the nuclear AGR sites at Torness and Hunterston B.

Well, yes. That's the great unanswered problem of the world; what do we do when that runs out or we can't burn it without exceeding safe CO2 limits?

Scotland already went through a period of energy resource shortage in the 1800s when there were very few trees left. Going back to only locally renewable resources might be like that again.

Well, my preferred solution is gigantic offshore tidal power generators in the Minch and around the top of Scotland where there are strong currents, preferably combined with hundred-kilometre-wide offshore wind farms (if you're building power generation structures in the open ocean anyway, you're an idiot if you don't put massive wind turbines on top of them).

Tide is one of the few renewable technologies that generates reliable power, and so is suitable for baseline load. Even in Scotland, the wind drops. But it's had very little investment, partly because of a poor reputation from horrific ecological damage caused by tidal barrages in the past, but mostly because wind is sexier.

But plants big enough to actually make a difference are going to be very, very big. Microgeneration is great for small rural communities, but we live in cities these days.

Here's a new 320MW tidal lagoon being built in Wales: http://www.tidallagoonpower.com/projects/swansea-bay/ These only work when attached to a coastline, though.

So that tidal lagoon... Is it basically a two-way dam that's taking advantage of the height differential between the interior and exterior? That's a pretty cool way to do it. Seems much simpler and more reliable than those wave-powered things that come out in news articles every once in a while.