Regenerative Braking
A friend wants my comment on a device that would somehow help large trucks achieve regenerative braking. While I don’t know the details, I point out:
I’m concerned that this won’t work as well in the real world as you think.
First, realize that, whatever this device actually is, it represents added weight and cost. Trucks don’t come with electric drive-trains, and thus somehow you’re going to need to account for the batteries, the motor, the mechanical parts that gather up and redistribute the energy, and all the other stuff that makes this work.
Then, as I’m sure you’re aware, it can’t be used to charge the batteries except when the brakes would otherwise be applied; you’d be using more fuel energy than you’d be storing as electrical energy; this is absolutely true by virtue of the second law of thermodynamics.
So the question is: how much energy is dissipated as heat in the brakes per a typical 1000 mile trip? I don’t know the answer to that question, but I’ve been told that it’s less than people commonly think, and I would guess that’s especially true in the case of long-haul trucks that can cook along across huge expanses without braking.
I’m told, and I believe it to be true, that regenerative braking only makes sense in vehicles like mail delivery trucks that have frequent starts and stops.
Craig,
Essentially, you are quite correct regenerative braking in large vehicles isn’t practical.
Ford and Daimler spent considerable time and money some years ago exploring the possibility of regenerative braking being used to increase the capability of braking (the braking capacity of large trucks is pretty woeful), but quickly abandoned the idea as impractical.
Large trucks usually “brake” through gearing not actual brakes. Stopping a thirty-plus ton behemoth takes a lot of energy and drivers quickly learn not to rely on the stopping power of wheel braking systems.
In more realistic news the German Aerospace Center is investigating whether Germany’s coal plants could be reused as energy storage assets.
A pilot project is planned involving ripping out the boiler from an old obsolete coal plant and replacing it with a molten salt thermal storage tank that will be heated using excess renewable energy.
By creating a sort of giant Carnot battery, coal plant generation jobs could be retained even if coal was no longer used. In times when surplus wind or Solar power wasn’t available, the shortfall could be generated from natural or LPG gas heating the Carnot battery.
Should prove to be an interesting project.
Back in the USA, the Department of Justice has asked U.S. Court of Appeals for the Second Circuit to dismiss New York City’s
climate change lawsuit against the oil industry.
The DOJ also stated an intention to enjoin any other action of this type, effectively blocking such law suits in any jurisdiction.
The DOJ submitted the court should reaffirm the ruling of the lower courts that the claims in these sorts of cases have no standing because they would entangle the judiciary in matters assigned to the representative branches of government.
This would appear to be the beginning of the end for all the Climate-gate lawsuits against the Oil industry, much as I predicted several years ago when this waste of taxpayer money was first suggested.