Sun and hydrogen 'to fuel future'(hydrogen fuel cell)

BBC NEWS ^ | 08/12/04 | Jo Twist

[TigerLikesRooster]

Ping!

[bolobaby]

In 2003, President George Bush announced an $1.7bn investment to turn the US into the world leaders of hydrogen-powered automobiles.

But... but... Bush is in the pocket of big oil! Why would he do this????

[GSlob]

"Using a 10% cell, we say that a seven-metre squared array will power a Mercedes A class car for 11,000 miles a year [in LA sunlight conditions] without going to power station," said Dr Auty.


At sun radiation at 1 KW/m2 at 10% efficiency the 7m2 cell would provide 700W=1hp during daylight. Mercedes uses a lot more power. So, out of 12 hrs daylight one could get maybe 6 minutes worth of the car running every day, probably less. A lot of fun.

[Normandy]

Encouraging article. This seems like a promising technology. How much more convenient to use water and sunlight to create the energy we need than digging in the depths of the earth and under the oceans for fossil fuels.

[AFPhys]

hard for me to evaluate the reality here, but i suspect that the speaker meant 7meters on a side = 49 m^2 ,,, which would be seven times your "6 minutes" ... if everyone here is accurate. i'm very skeptical of these estimates ...
.

[GSlob]

With 7 by 7 meter cell the car would become a sailing vessel and would not need the sunlight at all. Driver education would become a bit more tricky, though.

[plangent]

Good in theory, until you count up all the energy needed to mine the ore, refine it, smelt it, form it, and create all of those wonderful nano crystals needed to convert sunlight into H.

Somehow these whizbrains have left out all the energy needed to get to a working model that can't even power a 100 watt light bulb.

[RightWhale]

That would easily meet my transportation needs. Probably my electricity needs, too. Heating the humble abode in winter would still remain, and finding sunlight in winter would also. My latitude is 64 north, which is more northerly than Helsinki, and besides being dark all the time it can be 40 below or more for weeks at a time.

[cookcounty]

Time to short the Saudis? What are they gonna do?

[chipengineer]

>So, out of 12 hrs daylight one could get maybe 6 minutes worth of the car running every day, probably less.

You must be assuming the car needs 120 hp to run, but that is only under acceleration. 20 hp is enough for reasonable constant speed, so their 11,000 miles/year (about 30 miles/day) is reasonable with just 7 m^2 of panels.

[sully777]

Is hydrogen a volatile medium? Think Hindenberg. Think Hindenberg exploding.

How do you contain volatile hydrogen? In a cell form.

Does the weight of the cells cause problems? Yes, heavy vehicles are not as nimble and fuel effecient with system.

Where do we get hydrogen today? By a process using OIL. It is an expensive process.

I'll stick with gasoline.

[SauronOfMordor]

With 7 by 7 meter cell the car would become a sailing vessel and would not need the sunlight at all. Driver education would become a bit more tricky, though.

I don't think the idea is to have the unit on the roof of the car. More like the roof of your house, generating and storing hydrogen during the day, and you fill up when you get home. This would involve significant safety considerations, though.

[RightWhale]

Is hydrogen a volatile medium? Think Hindenberg. Think Hindenberg exploding.

Think Hindenberg, but think right. The hydrogen did not explode, it didn't even start the fire.

[nightdriver]

"The cells capture the full spectrum of ultraviolet light - the Sun's rays - and, via the novel coating, the electrons are captured and carried away on conductors."

What they have here is potentially a more efficient solar cell.

The application of electrolysing hydrogen out of water is just a come-on to get our attention.

[preacher]

If somehow there was a breakthrough which would lower the cost of running an automobile significantly, liberals would want to raise the price back where it was by raising taxes. There are all these social programs they could fund.

[GSlob]

Please add climate control, headlights and starts and stops at traffic lights to your estimate of energy consumption. At reasonable constant speed of 65 mph a car takes more than 20hp, unless it is something superlight. And they were talking a Mercedes.

[boris]

This is nuts, nuts, nuts...for reasons I have explained over and over again. Once more:

(a) Solar power is much too dilute to be anything but a niche market. Intensity of power generation creates economies of scale. A comprehensive list of intense sources: nuclear, fossil, hydro. Period. End of list. All the decent hydro sources are already fully exploited.

(b) Hydrogen releases 3.5 times as much energy as gasoline per pound but is 11 times less dense--so it is about 1/3 as efficient per gallon. I am talking about liquid hydrogen; gaseous H2 is hopeless. And liquid H2 needs insulation out the wazoo or active refrigeration.

(c) Where do you get the H2? From natural gas (ooh, that nasty carbon) or water by electrolysis--which is at best 70% efficient and must be driven by a fossil or nuclear plant.

For these and numerous other reasons, solar-derived H2 is stupid, stupid, stupid.

Let us not hear any more moronic ideas about this.

--Boris

[chipengineer]

>At reasonable constant speed of 65 mph a car takes more than 20hp, unless it is something superlight. And they were talking a Mercedes.

The picture was of a Mercedes A-class (very light).

65 mph is probably too high; more like 50 mph.

[balrog666]

BWAAAAAAAAAAAAAAAAAAHAHAHAHAHA!