> The cost of the scheme is in maintenance. No ground level access. No easy way to service panels in the middle of the roof. And lots of electrical current if you need to do something during day light because solar panels don’t turn off.
This is classic HN "armchair critic" comment. Yeah, I'm sure the designers didn't think about any of these issues. If they need to clean the panels, they can use a cherry picker. If they need to service the electrical components underneath, they can wait until the canal is drained (usually once per year for cleaning), and, again, use a cherry picker.
For clarity I was using “service” in a technical sense.
Ground mounted panels can be serviced from a bucket truck right after a hail storm or other disaster. Disaster recovery is a critical design criterion for electrical infrastructure and the bucket truck is the standard electric utility service vehicle.
Electrical utilities depend on each other and dispatch their fleets of bucket trucks across the country to aid in disaster recovery. If you drive much across the country, you might come across convoys of bucket trucks deploying down an interstate.
Which is to say cherry pickers don’t easily scale to handle the kind of critical events that need to be handled with electric utility infrastructure (and as an aside, in a pinch ground mounted solar panels can probably be serviced from a half ton pickup).
For context, in a former life I was an architect and one of my clients was an electrical co-operative. I also know a lineman socially.
You can read more about this project and the players in this article and draw your own conclusions:
Having to rent a cherry picker and being able to do maintenance only during a limited time per year significantly increases the cost of maintenance compared to an installation you can trivially access from ground level year-round. Canals being long and narrow don't exactly help either.
Sure, it can be done, but strictly from the PV perspective it doesn't make any economic sense compared to a regular solar farm when there's still plenty of land available. Similarly, from a "preventing evaporation" perspective going for a plain corrugated metal roof might not be much cheaper in installation, but it will be significantly easier to maintain.
Just because two thing can technically be combined, doesn't mean it makes sense to do so.
This is a classic HN “armchair critic” comment. Running a cherry picker team along a whole canal is far more expensive than maintenance would be on a field of solar panels.
Except getting permission to build your "field of solar panels" costs X times as much as a local/state controlled area to build. Is that you, Brandolini calling?
