I read this large hardback book maybe ten years ago from a UK library. I think it was eco sci fi (not sure about that) . The ecological disaster was possibly just the global warming thing of a few years ago. I'm not 100% it was an eco story. .... but a little voice at the back of my brain says yes.
All I can really remember is this inventor who has an idea for using a tiny thing that vibrates glass and it removes moisture. He patents this and becomes mega wealthy because windscreen wipers are no longer needed, this is easily fitted to all cars.
Later in the book (still no memories of the main plot!) this guy is back again, he has a big workshop full of high tech equipment and basically potters about waiting for inspiration.
One day he's off to a meeting but is caught in a traffic jam, idly he's watching some window cleaners on a skyscraper hoist and he gets idea two. He questions his chauffeur to confirm that, ever since the rain repellent device was fitted, the driver had never had to wash the windscreen either.
He builds his second mega fortune by getting his patented device installed on all high rise buildings so their glass never needs cleaned.
This is a minor part IIRC of the main book but very distinctive.