26 second video of MotionPower concept
For years we have complained that all these schemes to harvest energy from moving cars, like the recent installation at a Sainsbury in the UK, were just a very inefficient tax on drivers, but they keep popping up. When it comes to energy, there is no such thing as a free lunch; if a car goes over a device that generates energy, it is getting that energy from gasoline inefficiently converted to forward motion and equally inefficiently converted back to energy.
But New Energy Technologies may be on to something with their "MotionPowerâ„¢ Energy Harvesting". They only want to put their device where people are slowing down and would otherwise be using the brakes.
They are a bit over the top in their prose, writing that "Our technology is similar to what is used to power hybrid cars, but instead of being installed in each vehicle, it's installed in the roadways, capturing the friction energy that is otherwise dissipated as heat."- the only similarity to hybrid cars is that some have a form of regenerative braking, which has been around for a century. Other claims:
We drive an astonishing 6.3 billion miles every day in the U.S. If the kinetic energy generated by moving vehicles was captured at any given moment, it could produce enough electricity to power over a quarter million homes each day.*
If the kinetic energy generated by moving vehicles was captured twice per day, then it could produce enough electricity to power over half a million homes each day.*
*Based on 250,000,000 cars in motion at any given time, with each car conservatively weighing only 1,000Kg (2,205lbs) and reasonably expected to be traveling at 30MPH (15m/s).
Now they are putting them into a Burger King in Cary, North Carolina. The owner is quoted in Clean Technica:
"More than 150,000 cars drive through our Hillside store alone each year, and I think it would be great to capture the wasted kinetic energy of these hundreds of thousands of cars to generate clean electricity."
Where do I start? With the carbon footprint of drive-in restaurants, to the idling while waiting for the burger, to the carbon footprint of raising meat and making hamburgers? The installation of this at a burger joint is laughable. The energy it will generate is negligible, and It probably will take twenty years to recover the energy in it's manufacture.
But hey, if it makes you feel better about your burger, go for it. Drive toward that car ahead of you in the line but don't put on your brakes; just aim for those little plates in the road and hope that they slow you down in time. Trust the technology.
There may be a place for energy recovery from slowing down cars, but it is probably more effective if built into the cars as regenerative braking than it is from trying to externalize it like this, where energy will be lost through the tires and the mechanism itself. it just isn't very efficient.
More from CleanTechnica: Burger King to Harness Kinetic Energy from Speed Bumps
More "Energy Harvesting" speed bumps
Ramp Creates Power as Cars Pass (Or Does It?)
Sainsbury's "People Powered" Checkouts: Aren't They Petroleum Powered?