| |
Average speed of a car |
| |
adrianl (04:19 20/12/2008)
VincceH (09:31 20/12/2008)
rich (15:27 20/12/2008)
filecore (18:32 20/12/2008)
VincceH (20:03 20/12/2008)
monkeyson2 (10:09 21/12/2008)
Loris (18:06 5/1/2009)
VincceH (18:36 6/1/2009)
|
| |
|
Adrian Lees |
Message #109035, posted by adrianl at 04:19, 20/12/2008 |
Member
Posts: 1637
|
I was just watching a repeat of a James May show about alternative energy, bemoaning the fact that solar-powered cars can only achieve 'acceptable' speed on a bright summer day.... but really the average speed of a car is, say, 40mph for 2 hours a day, which is just ~3.5mph average. It's really a question of energy storage, even with our present - rather poor - solar cells. No?
I'd always criticised the poor conversion efficiency of our solar cells, given the obvious abundance of trees & plants, but perhaps they're actually no more efficient....*wanders off to investigate*
[Edited by adrianl at 04:26, 20/12/2008] |
| |
 [ Log in to reply ] |
| |
|
VinceH |
Message #109036, posted by VincceH at 09:31, 20/12/2008, in reply to message #109035 |
 Lowering the tone since the dawn of time
Posts: 1600
|
Well I don't think I've ever seen a tree get up to 40mph. |
| |
[ Log in to reply ] |
| |
|
Richard Goodwin |
Message #109041, posted by rich at 15:27, 20/12/2008, in reply to message #109036 |
 Dictator for life
Posts: 6828
|
Well I don't think I've ever seen a tree get up to 40mph. That big not-hurricane a few years ago moved a few of them pretty sharpish. And a lot of cars didn't seem to be able to outrun them[*].
* probably because they weren't moving what with it being sleepy-time, but still.
________
 Cheers,
Rich.
|
| |
[ Log in to reply ] |
| |
|
Jason Togneri |
Message #109044, posted by filecore at 18:32, 20/12/2008, in reply to message #109036 |
Posts: 3868
|
Well I don't think I've ever seen a tree get up to 40mph. Depends on the size of the tree, really. I've seen some saplings get up to quite a speed in a gale, tumbling merrily along the lane. |
| |
[ Log in to reply ] |
| |
|
VinceH |
Message #109046, posted by VincceH at 20:03, 20/12/2008, in reply to message #109044 |
Lowering the tone since the dawn of time
Posts: 1600
|
Well I don't think I've ever seen a tree get up to 40mph. Depends on the size of the tree, really. I've seen some saplings get up to quite a speed in a gale, tumbling merrily along the lane.
"Good news for people travelling East, tonight, as the winds in that direction will be up to 40mph..."
I'm not actually sure that works as an alternative for the internal combustion engine in cars.  |
| |
[ Log in to reply ] |
| |
|
Phil Mellor |
Message #109048, posted by monkeyson2 at 10:09, 21/12/2008, in reply to message #109046 |
 Please don't let them make me be a monkey butler
Posts: 12380
|
http://www.idiottoys.com/2008/12/extremely-impractical-new-lg-washing.html |
| |
[ Log in to reply ] |
| |
|
Tony Haines |
Message #109094, posted by Loris at 18:06, 5/1/2009, in reply to message #109035 |
 Ha ha, me mine, mwahahahaha
Posts: 1025
|
I'd always criticised the poor conversion efficiency of our solar cells, given the obvious abundance of trees & plants, but perhaps they're actually no more efficient....*wanders off to investigate*
Since trees &c are also busy living, it's the efficiency of photosynthesis (plus conversion to storage compounds like sugars if you like) which should be compared, rather than the energy in the resultant biomass. I've heard it's not actually all that efficient - sometimes the reaction is driven the wrong way (that is, the energy of light releases carbon rather than fixing it). This is an issue because the products (including oxygen) are at much higher concentration than the reactants (water and CO2). But until someone creates a better system to do the same process those whingers should probably STFU.
I also think that creating a chemical fuel is probably more difficult than creating electricity. So to be fair one should probably include the efficiency of either hydrolysis or battery storage in the calculations. |
| |
[ Log in to reply ] |
| |
|
VinceH |
Message #109102, posted by VincceH at 18:36, 6/1/2009, in reply to message #109035 |
Lowering the tone since the dawn of time
Posts: 1600
|
The average speed of a car is not very fast if you accidentally fill your petrol car with diesel!
Doh! |
| |
[ Log in to reply ] |
| |
|
