Energy Storage in Buses

Possibly of use in busses due to their start-stop nature - otherwise I don't think so.

Formula 1 with extreme braking actually collected very little power.

Too expensive for my taste. I don't see ever breaking even if it adds 33% to the cost of the bus.

But, I'm a skeptic.

Incredibly costly! It will never come close to paying for itself. Even the Prius, with its built-in regen braking is a mere 20% more expensive than a comparably equipped car -- and you get a specialized engine and many specialized systems in the bargain.

The price increase does seem outrageous, especially considering that the modification does not introduce significant new equipment....it only uses current equipment in a different way.

That said, even with what seems to be a hugely inflated purchase premium, even a moderate increase in fuel efficiency could result in a reasonably short payback period for investing in such a system.

The Prius comparison neglects some important considerations... public transportation busses drive many more hours and miles per day and over their expected service life than a commuter car and these busses stop and start far more often than a commuter car. Fuel costs are a much larger portion of lifetime costs for a bus than for a prius, and a bus operates in a range for which hybrid tech is very advantageous a greater percentage of time than a prius.

Bbb…..... flee to me remote elf

I agree with much of what you say re the relative gains from regen in commuter cars vs applications in which there are a lot of stops and starts. However, other hybrid schemes for such applications have used hydraulics and electric hybridization to good effect, at a lower cost increment and with more effective hybridization than they are proposing here. More effective hybridization reduces the size of the prime mover, so that it runs at a load closer to its peak efficiency. The article seems to understate the complexity of making an engine into an efficient air pump (and subsequently using the compressed air for supercharging) and further suggests that delivery vehicles already have large air tanks aboard, with is generally not the case.

In practice, the UPS and Fed X hybrid experiments seem to indicate that electric hybrids are more effective than hydraulic (as you'd expect) -- and neither requires fundamental changes in engine valving. Compressed air is historically very inefficient, and is, for example, avoided in industrial plants when electricity can be used instead. So I am skeptical... but appreciate your well-thought-out points.

Able was I ere I saw Elba.

I am in complete agreement. I am was not championing this particular system; I am certain there are a couple proven technology alternatives that would be more effective and less costly upfront and over life.

I was commenting on the comparison. Comparisons, especially analogies, wield sufficient persuasive power (both to self and others) to at times be dangerous. It is refreshing to converse with someone who is so little vested in being seen as right, as to consider criticism and right away accept valid points of contention without first becoming at least slightly defensive or combative.

I also appreciate the palandrome...

Here are a few of my favorites....

Go hang a salami, i'm a lasagna hog

God, a red nugget, a fat egg under a dog

On a clover, if alive, erupt pure evil, a fire volcano.

Evil i dwell lewd i live.

BBB.....