This is clever stuff. Audi is developing a new suspension system that can recuperate energy which is otherwise lost. The 'eROT' set-up uses electro-mechanical rotary dampers in place of more conventional hydraulic ones, which not only allows the car's suspension to charge a battery but also offers a more comfortable ride.
Audi's idea is that, with increasing amounts of electrified components in cars and the development of mild hybrid, hybrid, plug-in hybrid and pure EVs, energy capture plays an increasingly important role.
WOW, now I can try to hit all the potholes. I read about this a few years ago. I think it will never be cost effective. BMW was supposed to use exhaust heat to generate electricity and that seems to have faded away. Considering two thirds of the potential heat energy in fuel is wasted, it seems like much lower hanging fruit, and I can keep dodging the potholes so my car will take longer to fall apart.
The difference between generating electricity from the suspension or the exhaust is that it is fairly easy to convert the up/down motion of the suspension to a circular motion to generate electricity.
Trying to do the same from the exhaust where you are converting heat to circular motion is a lot more involved.
There is also the added bonus that your suspension is working all the time from the moment you start driving, even on smooth roads. Whereas the exhaust would have to heat up to a certain temperature before it could be used.
I can see this coming to a car near you in the not too distant future.
I say why stop there, why not have a series of miniature fans underneath the car, that when driving at high speed, spool up like turbines and generate small currents. Or perhaps small "water wheels" concealed behind the A pillar, and C pillar for when rain running down the roof guttering channels away. Wind and water power go back thousands of years, I'm surprised we haven't used it in some form or another on vehicles.
What about mini propellers underneath, using all the free wind at speed to power electrical equipment and recharge batteries?...I'm sure many WW2 vintage aircraft used that method. We could just turn half your fans 90 degrees Paul.
That's kind of what I meant, fans, propellers same difference to me lol. Remember back in the 90's you used to see those little vans with a tiny turbine on top, constantly rotating, even when stationary? Something like that.
Jets liners still have those propellers for power. It's an emergency system for when all the engines are out. It creates drag, and slows the plane down, so it will reduce the time and distance a crippled plane will glide.
Exhaust heat for electricity involved using thermoelectric generators. https://en.wikipedia.org/wiki/Thermoelectric_generator
Those 12 volt coolers use a basic version of these generators; pumping electricity into the material chills it.
The hurdle for using it to power a car's accessories from exhaust heat is cost.