New power-generating road ramps - another ill-conceived plan

[Andrew D]

See link to BBC News:- http://news.bbc.co.uk/1/hi/england/somerset/4535408.

Thought everyone would enjoy this; apparently there's a guy in Somerset that's developed a ramp that, when fitted into the road, derives energy from vehicles passing over it.

Apparently several councils are mad for it as a method of powering traffic lights (and I dare say scameras before too long, you know, keep as much cash from fines as possible).

Unfortunately, nobody seems to have considered where the energy comes from. It seems to me that the force taken from the car to push the ramp down will reduce the kinetic energy of the vehicle, and will have to be replaced by burning more fuel. More costs (and fuel taxes) passed to the motorist anyone? Not to mention tyre wear and increased polution.

Seriously, what's wrong with these people?

[Dave Dax builder]

Let's hope the £1M he spent on developing was his own.
Surely a scientist (If you can call him that) would have been aware of "Equal and opposite reaction".
More redirection of motorists money.

>> Edited by Dave Dax builder on Monday 19th December 22:03

[dogwatch]

The ramps may be silent, but so are road humps! The sound of tipper lorries crashing along nearby humped roads and bus drivers slowing down and then revving up again can be heard all over the district here. At least the street residents can say speeds are being reduced.

If the same amount of noise is due to a council power station they might have different opinions. Can't see that the economics make sense either without a huge subsidy.

[Andrew D]

Dave Dax builder said:

Surely a scientist (If you can call him that) would have been aware of "Equal and opposite reaction".

Ah, Newton's third law of motion, that old chestnut. I'm thinking no.

I have realised there was a slight problem with my assumption that the impact on vehicles hadn't been thought through; it assumes that they would actually give a damn. Which they most likely don't.

[victormeldrew]

Added benefit: it slows vehicles whilst providing "free" power. Link it to scamera and you can vary the amount of restistance/power generation so that all cars come off at 30mph regardless of what speed they start out at. Active scameras. Fines and enforced traffic calming at the same time.

[pdV6]

Andrew D said:

Unfortunately, nobody seems to have considered where the energy comes from. It seems to me that the force taken from the car to push the ramp down will reduce the kinetic energy of the vehicle, and will have to be replaced by burning more fuel.

Well, the car will convert kinetic energy to potential energy by climbing the ramp. Gravity brings it back down and runs the generator (and presumably a spring pushes the ramp back up afterwards).

So, yes, vehicles will be losing (kinetic) energy by driving over the ramps, but they will be anyway, assuming that the other option is to put in a solid speed ramp.

What ticks me off is that we're the ones going to pay for all of this, and presumably its many orders of magnitude more expensive than a strip of raised tarmac...

[Andrew D]

pdV6 said:

Well, the car will convert kinetic energy to potential energy by climbing the ramp. Gravity brings it back down and runs the generator (and presumably a spring pushes the ramp back up afterwards). So, yes, vehicles will be losing (kinetic) energy by driving over the ramps, but they will be anyway, assuming that the other option is to put in a solid speed ramp. What ticks me off is that we're the ones going to pay for all of this, and presumably its many orders of magnitude more expensive than a strip of raised tarmac...

I'm not actually sure that they are intended as traffic-calming measures (the BBC article isn't clear on it). Indeed they are touted as a method of powering traffic lights and illuminated street signs, which are rarely coincident with traffic calming, which would suggest a purely power generating purpose.

But even if they were a replacement for conventional speed humps, the law of Conservation of Energy dictates that you rarely get anything for free. Whilst the action of climbing the speed hump converts kinetic energy into potential, the action of rolling off the otherside converts it back into kinetic (with a loss factor for the inefficiency of the process due to frictional losses etc). However in the case of the energy generating ramp, the potential is used to compress the ramp and drive a generator, and thus converted to electrical energy.

[Scraggles]

guess they will be at traffic lights and road signs, ie the things they are going to power.

What do most people do at those things ? Stop ?? Energy gets dumped to brakes or to the generators....

[desmo]

there are several points that seem to have escaped the "inventor" and the rabid council purchaser's who are crying out for this minger of an idea.
1. LED type traffic lights could be supplied by solar panels and battery, it would be cheaper too. Easier installation. More reliable. Not dangerous. Eco friendly etc,etc.
2. Metal plates are slippery as f*** when wet, especially if your on a motorcycle.
3. The points mentioned about transfer of energy etc.
4. You could probably save more energy by removing all speed bumps and cameras, less braking and therefore less re-accelerating required, so less energy used for the equivalent approach speed.
5. Confusion if it is placed infront of traffic lights, why are you slowing for a green light! people behind unfamiliar with the road may be caught out, so it will increase accidents.
This idea needs knocking on the head before it's too late. Oh he's already spent a million, what an idiot.