Sounds like they're inhaling smoke in La-La land again -- but it ain't from Diesels...
Looks like the bozos at the Sacramento Bee confused the issue with that captioned picture of the tractor.
Near as I can figure, the article and legislation is just about diesel-electric pumps used for irrigation, not diesel tractors.
I don't know for sure, but I would guess the standby surcharge that the utilities are clubbing the farmers with is merely the "deregulated" market at work. SOMEBODY has to pay for the luxury of holding "excess" unefficient capacity in reserve for when the farmers need to kick in their electric pumps. (Can't blame the farmers for shifting to their own diesel-electric generators to avoid the surcharge.
Of course, the solution under the old, regulated public utility model (that served our nation well for many, many decades) was to intentionally build sufficient capacity so that there was always plenty available for everybody.
There was nothing wrong with that at all, as long as the regulatory agency was "friendly" toward the utilities. But the enviro-whacknuts hijacked the regulatory agencies and created an "unfriendly" business environment. Then the beancounters at the utilities gave up fighting the enviro-whacknuts and came up with the bogus "deregulated" shell game, which is gonna screw everybody with higher rates and shortages.
Sad state of affairs, IMHO.
Kalifornia still needs to build more nukes.
But I don't think Arnie is gonna pull it off.