I dont think you realise how wast the northern sea areas are, there is alot of oil waiting up there. But obviously, one day the oil adventure ends. Hydroelectric is pretty huge in our country, that and wind power could cover alot of our energy needs. But there is not so much profit in it, true.
The North Sea oil & gas production has been declining non-stop for over a decade now, and that is for all countries concerned, in fact the relative decline has been even worse for the UK, the Netherlands and Denmark than it was for Norway. Sure there is more oil up there, but it is not nearly enough to even keep your diminished production stable. Not all oil deposits are of the same value. The most accessible oil is found in the Middle East (mainly Saudi Arabia, Iraq and Iran) hence all the wars over there. Also, in Russia who is the one oil & gas giant that can defend itself from western invasions. Hence all the hysteria and subversion against that country. It really is ABC, but you are not going to hear about it in the "free media"
The West (mainly the US and secondly UK+France) is on good terms with the Gulf states, but does not control Iraq, Iran, Venezuela and let alone Russia. Even the western grip over the Arabian peninsula could be in doubt with the rise of China. It is for this reason that we are now in a new Cold War and risking even WWIII.
There has been talk of the "end of the oil age" for decades now, but do not hold your breath for it. Oil remains the most versatile, most energy dense, most strategic (no army or navy can operate without it) and most profitable energy source on the planet. People in the west are lied to systematically and fall for it. If you think Marca and Sport are publishing BS, then you have no clue what inanities and outright lies publications like The Economist and New York Times get away with.