It can if you have enough space and money to build a large enough system, but it is costly. You would have to work backwards from peak-winter to figure out how much energy you can generate, and ultimately have a good amount of batteries to store it. They control our access to fuels, but - for now- they can't control our access to the sun. I only have one person in my circle who has managed to go completely off-grid, but they are not in the UK.