Kinetic Road Plates

The issue of kinetic road plates came up again today. Doesn’t it sound like a great idea – harvest energy from cars passing over a compressible ramp in the road to drive a generator?  Free energy, as long as people keep driving cars.

But hang on – where is this free energy coming from?

Well, since energy cannot be created nor destroyed, it clearly must come from the car’s engine as the only power supply in the vicinity. In order to compress the ramp the vehicle must first drive up it’s incline. The increase in gravitational potential energy created by raising the mass of the car is then converted to kinetic energy as the ramp gently compresses and drops the car back down to road level, driving a generator to create electricity. But, in order to raise the car up the ramp in the first place consumes more fuel, exactly like driving up a hill.

So, rather than harvesting free energy, the kinetic plate is actually stealing a little bit of energy from each car passing over it. That energy must be replaced by burning more fuel; it’s just that the amount of fuel taken from each car is so small that you’d be unlikely to notice.

Now one of the first adopters of this technology is a national supermarket chain – very clever – the supermarket also sells fuel from its own petrol station, so they are onto a double winner. The store gets a free supply of energy from its customers and then sells more energy to the same customers to replace the energy it has stolen from them.

7 thoughts on “Kinetic Road Plates

  1. Hi Doug,

    many thanks for coming back to me. You have the skill with which to view this technology objectively however I am looking at it purely as a marketing enterprise and I have already spoken to people in Qantas and Emirates who very keen to get involved. If you do have contact details of key people who are primary to the definitive details that would be great.

    Thanks again,


    • Lee, Please see my separate email. I believe that the roadplates installed in Gloucester were not robust enough for the imposed wheel loads of trucks delivering to the store.

  2. I need to get access to somebody who wants to market this technology worldwide as I can do that. I have seen the units in operation at Sainsburys in the UK and want to trial the system in Australia with full support provided as a trial bed.

    Please tell me how we can best achieve this?

    Kind regards,

    Lee Brewis. – ex winner of two Queens Awards in one year for International Trade and Technological Innovation.

    • Lee, the technology has been around for years and several companies have experimented with it as far as I know. The fact that it has not taken off is probably a good indication of its usefulness. You will be aware from the piece above that I am skeptical about something that simply robs energy from passing cars. Even if used in braking zones these devises will not recover as much energy as proper regenerative braking.

  3. This was my first reaction, but it does work if they’re in the right place.

    If the car/lorry is braking when they go over this strip then it acts like regenerative braking on an electric car, capturing back energy from the momentum of the vehicle as it slows, and helping it to slow down too.

    Of course if the vehicle has regenerative braking anyway, or has no need to slow down at the time it passes over the strip you’re absolutely right. It’s like having a wind turbine on the roof of your car.

    • We are on the same wavelength. If you want to improve the energy efficiency of road transport then you should address the vehicles first and implement regenerative braking, keeping the energy in a closed system, not removing energy from the system and degrading it in order to use it elsewhere.

      • Part of the problem is that planners and some disciplnes of building designer simply don’t understand the science, and perhaps never will. I attended a seminar where someone who should have known better was extolling this ‘free energy’ from road plates. The response to my scepticisnm was shock that this was being questioned, followed by some bemusement and perhaps a dawning of the reality. but that tlak had been given many times before. Planners can only believe what they are told, and it is the sellers of gimmicks that provide the free seminars and sell their products. I on the other hand promote the avoidance of gimmicks, but there is nothing to see.
        Perhaps every local authority should have the return of the ‘Borough Engineer’ who can understand and question, and impose common sense.
        By the way though a generating road plate would work well at the bottom of a car park ramp, and really provide free power.

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