How long until...

B@Th*nG said:
aren't they going to avoid them all together and use hydrogen instead? as nobody wants a car which isn't as good as their old, and electric just isn't versatile enough.

B@
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Maybe once fuel cells are affordable. Nobody wants cars that cost 5 times more than their current ones and they cant refuel it.

Hydrogen fuel cell = electric car.
 
No idea really. If its timed to be done at night you have to first make the demand match the idle power output of the stations before you even worry about having to make more power than usual and thats then a long way from more power that can currently be provided.

With good control and using precharged cars that are set to park until a set time so the grid can use them as buffers to draw power from in peak load conditions I have seen reports that the UK could support 17 million cars doing average use.
 

Moreover, hydrolysis is only about 70% efficient, compression of the hydrogen about 90%, conversion to DC
electricity by the fuel cell at most 65% at the motor output stage, resulting in electricity-outlet-to-motor-output
efficiency of about 41%. In comparison, directly charging a Li-ion battery in a PEV involves AC-DC battery
charging at about 89%, battery efficiency of 94% and DC-AC conversion of 95% resulting in about 79% efficiency.
Because of this and the comparative costs, a group of experts from the US National Research Council has suggested​
that PHEVs offer a far more promising alternative to traditional vehicles than FCVs.
 
Jonnycoupe said:
You seem to be working on a battery system that chargers 100% efficiently and a drivetrain that gets 100% of the battery energy to the wheels. :p

1.5 m with a very bright 1000W gives 500W woth the most efficient and expensive solar panels at 35%. Commercial affordable stuff at the moment wont exceed 20% so you only looking around 5.5KW

4000lb truck would take an age to get to that speed is your first issue and you need to consider aerodynamics and rolling resistance.

I have a 10KW motor i mine, if I went pure EV id certainly want more than 15kW!
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Dogbreath said:
Petrol cars don't require vast amounts of power to roll along a flat, windless road at 50mph either. Rolling resistance and aerodynamic drag are not huge at these speeds.

What this simplistic view leaves out is how you get to 50mph in a reasonable amount of time, or have the ability to ascend a gradient. A modern heavy pickup truck with a 20hp motor would be pretty much unusable on public roads.
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Well in the book I've been reading the author has calculated drag, rolling resistance, resistance due to inclines etc at speeds from 10-90mph so I'd assumed the author had taken it into account :p Although indeed I did miss out the bit about solar panel efficiency. The section I'm reading is focusing on modifying a standard truck to be powered from batteries and hence leaves the standard gearbox in.

You could put the EV into second gear and leave it there, because it gives you 2 mph/sec acceleration at startup, hill-climbing ability up to 15 percent inclines, and provides you with enough torque to take you up to about 52.5 mph. For mountain climbing or quick pops off the line, 1st gear gives you everything you could hope for at the expense of really sucking down the amps, current-wise. But at the other end of 1st gear, if you drive like there’s an egg between your foot and the accelerator pedal, it actually draws only 100 amps at 45 mph versus the 210 amps required by 2nd gear. At higher speeds, 3rd gear lets you cruise at 60 mph at 270 amps, and 4th gear lets you cruise at 70 mph at 370 amps. At any speed, 5th gear appears marginal in this particular vehicle; though it can possibly hold 78 mph, it requires 440 amps to do so.
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Given the author thinks a 20bhp electric motor is an acceptable replacement for a 90bhp petrol engine, the figures he gave that I've quoted make it sound acceptable but obviously not blisteringly fast.

Going off these figures though it does look like powering your car by yourself currently would only be possible if you have a very low powered car. If solar panel efficiency were to increase then it might improve but only up to a point.

It does leave me thinking the article I quoted earlier may not be entirely accurate
a system on a home's garage roof that is 10 percent efficient could provide enough hydrogen for a fuel-cell car to drive 11,000 miles per year.
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Perhaps the author has a garage the size of a warehouse? :D
 
Jonnycoupe said:
Surface area of a roof is larger on a house.

Surface of a roof is not curved.

You dont need to carry water with you nor an electrolyser.

You can continuously generate gas at home into a large tank, then popping home allows refil like a normal car.

The sun gives 1000W on a sunny day in the UK. Galium arsnide panels on say a 1.5sqm roof would give you around 500W. Thats nothing your home vaccuum cleaner may use 4 times that so you cant drive soley on sunlight unless you go for a solar car design and only drive on sunny days.
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Damn your science. :p

Edit: how about another plan for you to destroy: next year I have bills included in my student house. How about I invest in an LPG-run car, buy a compressor, and use my home gas supply to fill up? :p
 
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You will want a CNG Civic (another Honda) for that one then and the compressor is in the region of $5k for home fill and never go to a petrol station again. LPG is a totally different thing to what is piped to your home. :p
 
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Haha for some reason I thought piped gas was butane :p
My distant recall chemistry is reminding me of some process for shortening hydrocarbons, but can't remember one for lengthening them, so if it can be done it's clearly not going to cheap, and certainly not worth it for one year. Plus the landlord would hate me so much.
That's quite a lot of money for a compressor, I didn't realise they were that expensive!
 
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