We already have efficient enough solar panels to make our homes self sufficient, we just can’t afford to buy them.
Even if we could, the power supply industry would see it happening, bribe and persuade the government to make it illegal to go off grid (I’m sure their solicitors would come up with “good” reasons that we should be stopped), to save their poor little shareholders.
No way will they go down without a fight. Would I love to go off grid? Sure. If I had a few grand of spending money I could easily do it. But that’s just one person, no way they’d let the entire country do it.