The book is about the UK, not the US.
The UK has much, much less solar potential than the US. The southern most point of Great Britain is further north than the northern most point of the contiguous USA. And it's really, really rainy here too.
The UK has much, much less solar potential than the US. The southern most point of Great Britain is further north than the northern most point of the contiguous USA. And it's really, really rainy here too.
Also, obviously, there is a significant range depending on location in both the UK and the US:
- in Yuma, AZ you will generate 3.19 kWh per year average (and the lowest, December is only 74% of peak in May!)
- in Seattle, WA you will generate 1.95 kWh/day average (with winter 27% of peak)
- in Oban, Scotland you will generate 1.35 kWh/day average (with winter 10% of peak)
- in London you will generate 1.6 kWh/day average (with winter 17% of peak)
The nice thing about solar, though, is that you can just overpanel for whatever your needs are. When the panels are so cheap, under $200 for a giant panel, you can just throw up some more panels and bam, you have enough solar year round. Obviously there are places far enough north to get too much darkness and snow to make year round solar realistic but even in most of the UK it is totally realistic to run off solar year round.