Those capacitors are supposed to store up the electricity that is generated by the train when it applies the brakes. I suppose that is sensible. The problem is $4 million and what is the annual cost savings? About $160,000. Not even the value of the investment. Not even the value of the money at 5%.
That doesn’t make any sense but it is just another example of how green technology is supposed to provide jobs. By having us waste $4 million to save less than 5% of that every year and the equipment will probably wear out in less than twenty. That is an awful lot of money wasted for almost no savings.