Re: Isn't this a solution looking for a problem?
I'm afraid it's part of a long list of legal breaches by the operators of the service station concessions in Germany who know a captive market and a lazy regulator when the see them. Toilets are supposed to be free to use but no longer are: you have to pay for a ticket that you can redeem when you buy something from a shop. And, because most service stations are full of HGVs (presumably including many of those not running in the UK) the outgoing government has a wheeze to encourage even more of them…
But the any environmental damage is likely to be limited: most of the places have taken advantage of generous government subsidies for solar panels and, are thus, largely off-grid.