What are the (software) opportunities for coming Green Revolution?

I don't think a green revolution will change much as far as software development. Most of the stuff you are mentioning already have companies that provide solutions/products, or at least have them in development. The main constraint is that energy revolution will really be driven by the hardware/physics. The software can help, but stuff like battery management or sun-tracking solar panels is existing software, and are really only useful if you have the hardware to work with it. People pay for hardware, the hardware providers will provide software options (look at Tesla). I would think you would not be able make a successful business around the software itself unless you have a novel idea that is built off of some undiscovered or untapped physics principle that greatly increases efficiency.

The second order areas you mention are almost certainly "liquid markets" where software consumers can buy the software production they need at prices they expect the market to require...or to put it another way, the there-is-an-unmet-need-for-software-expertise premise is suspect. Power companies,fleet operators, HVAC controls manufacturers, etc. already have access to people who provide them with software. These things are new to you, but the reason you see them is because they are established.

Solar farms are widely distributed and ordinary across the US, but they tend to be in rural areas off the beaten path...I remember my sense of wonder discovering one unexpectedly in west Georgia (the state) only a couple of years ago. And wind turbines? They are everywhere in the western US, but still amaze me.

I'd put it this way, if you knew a lot of truckers fleet management software would not smell like a greenfield. It's older than GM's onstar service.

When it comes to industrial applications, lots of people have been sitting around thinking what's-next for a long time. They work in organizations capable of funding making-it-happen via ROI.

These aren't bicycle-sized-project. Bicycles can be built by as small team (even one) with jigs and brazing rods and a components closet. A salable electric car can't.

Good luck.

Beyond the obvious "IT needs will likely still be there", I have two possibly contradicting hunches:

- on one hand, can software in general be a definite "plus" on the question? Should we maybe look for solutions that don't involve too much software, as the footprint of everything software (taken widely and including intensive machine learning, for example) is already pretty big?

- on the other hand: assuming software is required "in large amounts", maybe there is room for heavily optimising all the things involved in building and running software.

With the observations above, if I'm interested in continuing to work with software, working on computational efficiency questions could be interesting and possibly useful.

Even the sexiest companies need the IT basics: inventory, payroll, marketing, etc.

A lot of it is system integration, not greenfield development, but of course all tech work exists somewhere on that continuum

Build an website for NIMBY's to see where proposed nuclear power plants and wind farms will be built, make it easy for them discuss with each other and to participate in the projects' consultation process.