Space is only at a premium because it costs more to have more space.

The real question is "how much space are you willing to sacrifice for energy self-sufficiency?"

In the UK, electric bills hover around $1200 a year for electric/gas households and $2000 a year for full electric.

Renewable households will have a HUGE potential market.

U.K. Residential market is 26 million houses. Theoretical price point of $1500 dollars (one years energy cost) = 39 billion dollar market not including the massive combined secondary services in maintenance, installation training providers, parts, etc.

USA residential would be 6 times that and the provision of renewables to corporates is almost incalculable.

It's an entirely new economic ecosystem divorced from petrochemical.

It a price point higher than $3000 dollars we are getting into a market cap of many trillions worldwide.

IF you can get a solar system and batteries for £1k, then that starts to look feasible. But that's a big if.

I had a 3.8kW solar system put in for £5k last year and have yet to really run the numbers on savings; the payback period is 10 years of feed-in tariff cheques. If I went off-grid that would be reduced. I don't really see why I'd want to go off-grid for its own sake, I'd rather better explore the possibilities of net metering and sharing power with the rest of the city.