Is the answer to our energy problem hydrogen?

Question

Mythbusters showed a car run on hydrogen with hardly any modifications. Also, hydrogen seems relatively easy to mass produce.....water + electric

What the heck is the problem???????

Answer 1

As soon as we discover giant hydrogen puddles we will be all set.

Toyota and GM both announced that there is NO FUTURE for fuel cell vehicles.  Check it out in the news.

Here's a question for you, at what temperature and pressure can hydrogen be stored as a fuel for use in cars and trucks?

Answer 2

Electrolysis is not an efficient way to produce hydrogen, you require a much larger input of energy than you will get back from burning the hydrogen produced.  Net result, higher overall energy use.

Answer 3

the only reason i feel that hydrogen would not work as a biofuel:

it would be EXTREMELY dangerous. Hydrogen is extremely flammable, so if there was a car accident, there would most likely be a large explosion made, not to mention the other hydrogen cars around the blast, which could possibly cause more blasts....

Answer 4

it might well be an answer to energy storage and distribution.

hope so, i have wanted a hydrogen car since i was a teenager.

problem? inertia of established businesses, unhealthy ties between oil and gov. etc. all political, not technical.

Answer 5

The oil companies do not sell hydrogen.

Also, it is relatively easy for anyone to produce hydrogen, as compared to drilling for oil, thus destroying the oil companies monopoly.

Hydrogen is volatile, but so is LP gas and gasoline. There are ways to make is as safe as gasoline.

EAST POLE: Good points. Your energy, efficiency vs pollution math makes perfect sense.

I do agree that ultimately, electricity is best for transportation. Though it would be more cost effective to go hydrogen first  as you could modify existing vehicles. That would be the single biggest cost going all electric.

I was at Cal State in the '70s and some guys took a Mercury Bobcat (think Ford Pinto) and made an electric car. I would help them on occasion. It was run by 48 volt bus batteries. We used a lawn mower engine to charge them. When the volt meter got to 46 volts or so, we had to hand start the lawn mower engine. Not exactly hi tech but certainly the principal behind the hybrid.

The main problem was coupling the output of the electric motor to the wheels. That was a challenge. Once they got that figured out, they were getting over  70 miles per gallon. There was still much room for improvement.

You are correct about the internal combustion engine and 20% efficiency. It's actually late 1800's technology.

The great thing about electric cars is when you are coming to a stop and the vehicle's inertia is turning the wheel, the motor becomes a generator and dumps power back into the batteries.  

Also, when you are stopped at a light, you are using no energy.

Electric is the way to go and solar is so under utilized. By this time I would have thought we would at least  be supplementing conventional power with solar.

Silly me.

Answer 6

" water + electric "  <--- that is the problem right there.

(The use of electric current to break water up into H2 and O2 is called hydrolysis.)

How do we make the electricity that could be used to create hydrogen? If we live in the US, China, Australia, many parts of Canada, Russia, Eastern Europe, or South Africa, it comes from coal.

  

We have lots of coal, but when we burn it, only some of the energy is converted to electricity -- perhaps 35% in a modern turbine. The rest is lost as heat.

Then we have to use that electricity to make hydrogen and oxygen gas from water. This is perhaps 60% efficient. We're now down to (0.35*0.60=0.21)  21% process efficiency, but we're not done yet.

Internal combustion engines produce a lot of heat along with the driveshaft horsepower they output. These engines, found in all modern (fuel-burning) cars are about 20% efficient at moving the car forward.  So, from electricity to the turning wheels, the overall efficiency is

0.35*0.60*0.20 or about 4%.

That's really not very good -- we'd be pouring smoke and CO2 out of our power plants just to get a little bit of H2 in our tanks. Of course, there's no infrastructure to safely pipe, ship, or truck H2 around the country, so it would take a while to build that up, assuming we didn't want change our driving habits too much.

The one really good thing: very little local pollution. Actually, burning H2 with O2 is hot, so you still need a catalytic converter to prevent the release of NOx gases that are a component of smog.

But, assuming you burn coal or natural gas to make the electricity, you won't see a net decrease in air pollution since you need so much electricity to make H2.

I think H2 is relatively useless as an energy-transporting medium, because we already have a form of energy that we transport very efficiently across whole continents, generate in a variety of ways (some of which don't create much CO2 at all) and store in (some) cars.  We even have very efficient motors to turn this form of energy into motion. It is electricity.

If you do the same efficiency calculation as above for an electric car, you'll find its much higher than 4%, partly because there is one fewer transition (no electrolysis). Also, electric motors are much more efficient.

While those lucky areas that have a lot of hydroelectric dams, nuclear, wind, or solar-generated electricity might choose to make hydrogen, they'd still get more "miles per kilowatt" if they went with electric transportation.

Check out this sports car that runs entirely on laptop batteries:

http://www.teslamotors.com

With 220 miles (354 km) per charge, I suspect most of us would at least be able to commute to work, which is getting harder as gas prices continue to wander upwards.

To some extent, the equation you started with is wrong too; only four percent of hydrogen gas produced worldwide is created by electrolysis.  Mostly we get it by cracking the hydrogen out of a hydrocarbon like natural gas, which produces CO2 immediately.

I'm glad you asked the question, because there has been a lot of noise about hydrogen, first as a "source of energy" (which I hope we now agree it is not) or as a carrier of energy. In this second role it is clearly inferior to electrical current. The cheerleading for hydrogen has been pretty steady for the last 40 years or so, but we are no closer to having good reasons to build a hydrogen economy.

Answer 7

You nailed it! Hopefully once they figure out how to produce it cheaply in great quantities and gouge us  for it, we will be able to use it instead of petroleum.