- #1
spikenigma
- 61
- 0
Hi,
(Firstly, This is not a perpetual motion discussion. Nor am I suggesting anything of the sort. I'm just wondering where the energy losses enough to stall the system creep in.)
ok, I was having a discussion at lunchtime which I didn't have an answer to , so I'll post it here:
A Nissan leaf (http://en.wikipedia.org/wiki/Nissan_Leaf) is sitting at the top of a slope.
Along the length of the slope are rollover power generators (http://www.fahad.com/2006/03/electro-kinetic-road-ramp-clever-idea.html , http://news.bbc.co.uk/1/hi/england/somerset/4535408.stm)
The power generators are connected via superconducting material to an energy storage device at the bottom and charger which can recharge the car.
In short:
Variables
Efficiency of storage device and charger
Number of rollover generators
Gradient of slope (which will increase the constant energy consumption of the car by its percentage amount)
Length of slope
Constants
34kw per 100 miles for the car
10kw per rollover ramp generator
Now, the main point was that it is unclear when the system will stop working, because:
a) The car will always regain velocity (and thus any energy lost to heat, sound, light, friction) between ramps.
b) (Beyond "something like" 10% efficiency) it will also always generate more energy getting down the hill than it needs to drive back up it and thus will produce an excess - thermodynamically impossible.
Some quick back of the envelope calcs (don't crucify me):
Variables
Efficiency of storage device and charger - 30%
Number of rollover generators - 50
Gradient of slope - 20%
Length of slope - 100 miles
* Going down the slope, the car produces 500kw of power
* The Energy device can store and use 150kw
* The car uses 40.8kw to drive back up the hill
(Firstly, This is not a perpetual motion discussion. Nor am I suggesting anything of the sort. I'm just wondering where the energy losses enough to stall the system creep in.)
ok, I was having a discussion at lunchtime which I didn't have an answer to , so I'll post it here:
A Nissan leaf (http://en.wikipedia.org/wiki/Nissan_Leaf) is sitting at the top of a slope.
Along the length of the slope are rollover power generators (http://www.fahad.com/2006/03/electro-kinetic-road-ramp-clever-idea.html , http://news.bbc.co.uk/1/hi/england/somerset/4535408.stm)
The power generators are connected via superconducting material to an energy storage device at the bottom and charger which can recharge the car.
In short:
Variables
Efficiency of storage device and charger
Number of rollover generators
Gradient of slope (which will increase the constant energy consumption of the car by its percentage amount)
Length of slope
Constants
34kw per 100 miles for the car
10kw per rollover ramp generator
Now, the main point was that it is unclear when the system will stop working, because:
a) The car will always regain velocity (and thus any energy lost to heat, sound, light, friction) between ramps.
b) (Beyond "something like" 10% efficiency) it will also always generate more energy getting down the hill than it needs to drive back up it and thus will produce an excess - thermodynamically impossible.
Some quick back of the envelope calcs (don't crucify me):
Variables
Efficiency of storage device and charger - 30%
Number of rollover generators - 50
Gradient of slope - 20%
Length of slope - 100 miles
* Going down the slope, the car produces 500kw of power
* The Energy device can store and use 150kw
* The car uses 40.8kw to drive back up the hill
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