Also English language books are going to be predominantly sold in English speaking countries. And it makes sense cost wise to target both markets together rather than printing individual runs priced for individual countries where possible.
And Canada and the US both use dollars; there is potential ambiguity in price for manufacturers and retailers, so better to clearly specify both. There is not ambiguity with the peso - if a customer sees a book is $10 they will know there is a different price in pesos.
For electricity generation: Solar across the UK was about 5% in last year, while Wind was about 29% and Nuclear 13.9%, and hydro 1.3% - so 49.2% of electricity generation over the last 12 months was carbon neutral.
That’s a huge success story - still a long way to go, particularly as that does not include Gas burned in homes, but the UK is moving in the right direction. And Scotland is a huge source of Wind & Hydro power for the whole country.
So even if the barriers to solar in your home are still high, the grid is getting cleaner and cleaner every year. There are also community projects installing wind generators which you can join/invest in if you do want to try and get a slice of cleaner energy and solar is not realistic.
Edit: Source on UK electricity generation: https://www.energydashboard.co.uk/historical Good data on UK electricity generation