Back at the 2008 Detroit Auto Show, we talked with Jim Stansbury, the founder and CEO of the Physics Lab of Lake Havasu, about his company's slightly quixotic quest to modify a Chevy Blazer so it wins the Progressive Auto X Prize. Stansbury and his crew are now also operating as Regen EV Shocks because of a new addition to the Blazer: hydraulic shocks that generate electricity while driving. It works on the computer, as you can see in this flash demo, but just how much energy the truck can gain from these is something that'll be proved by the numbers on the road. Speaking of which, Stansbury told AutoblogGreen that the system might produce around 5-10 kW/hr. I asked if speed bumps would produce more energy and he set me straight on that account. Read all of his response after the jump.

[Source: Jim Stansbury / Regen EV Shocks]
Email from Jim Stansbury:

The energy is not a constant, and if I had a donated Tahoe Hybrid, I could give you an exact number. But since we are light that \$50k at this point, we will interpolate.

The speed bump is more a nuisance than anything, because it is a bump. Actually, there is constant road variation
on the streets @ less than 35mph typically, about 1 inch constant shock travel.On the highway there is less frequent large variation, just because most highways are relatively smooth, with less potholes.

So, the simple answer is just that as a kW number, from combining all 4 wheels, the magic number seems to lie near 5-10 kW/hr on a big heavy vehicle like ours. That is maybe 10-15 hp. Not much, but, when you make it for "free" after the initial investment, it can be of value. Since you cannot manufacture gas or diesel fuel as you travel down the road, but you can electricity, it has worth. It is not the magic bullet, but when you substitute that number instead of an extra battery bank purchase, it has value. Likewise, if we take that electricity and use it to convert water into hydrogen, to help efficiency and emissions of an IC engine, there also is value.

How much does it cost? Another holy grail type question. How many do I make, who makes them, and so on. These are economy of scale questions, along with more hard data and testing info, that remains to be figured out. \$5k?

So to answer your question, I think there are some variables that are still untested, and that will progress as we have more time with the vehicle. The extra weight is perhaps 1-200# max, so the ROI, and retail price, is still not an exact number yet.