1. The long journey from electricity back to electricity again!
  2. Chicken and egg
  3. Range issues
  4. Hard to store
  5. Nitrous oxides in combustion engines
  6. Some more good reading

1. The long journey from electricity back to electricity again

Think of it hydrogen as a battery, and not a very good one. It is not an energy source but an energy carrier. A poor one. If you have enough electricity for 100 miles and charge an electric car, when that car runs it will return maybe 86 miles of it. It’s about 86% efficient. Hydrogen only gets you about half that – 43 miles.

Why? Hydrogen takes more steps to make and use. Each step uses energy. First we split water to get hydrogen – and that loses 20%. Then we freeze and compress the hydrogen to try and cram this loose gas into a tight tank. 5% more energy wasted. Then we run it through a fuel cell which is only 60% efficient anyway. And what have you done? Turned it back into electricity to make the car go – which is what it should have been left as in the battery! It’s a long, lossy, round-about way of getting electricity off the lines, into water, into hydrogen, compressed into a tank, into a fuel-cell and finally back into electricity.

And electric car just dumps the electricity straight into a battery ready to go! The Wiki on the hydrogen economy has this graphic which illustrates the losses. (Click to view larger).

2. Chicken and egg

Hydrogen suffers from the chicken and egg problem. No one wants to buy a hydrogen car until there is a “hydrogen highway”, and no one wants to build a hydrogen highway until there are enough customers to guarantee they get their money back and some.

3. Range issues, far more refuelling required

This isn’t the end of the world, but hydrogen just won’t get you as far as gasoline. As the hydrogen economy wiki says:

The liquefied hydrogen has lower energy density by volume than gasoline by approximately a factor of four, because of the low density of liquid hydrogen — there is actually more hydrogen in a liter of gasoline (116 grams) than there is in a liter of pure liquid hydrogen (71 grams). Liquid hydrogen storage tanks must also be well insulated to minimize boil off. Ice may form around the tank and help corrode it further if the liquid hydrogen tank insulation fails.

4. Hard to store

Hydrogen also leaks, corrodes pipes and tanks, and is explosive. Storing long term is not really that big a problem if we are mainly using it for long-haul trucking in some sort of oil crisis emergency.After all, all it requires is electricity + water and a few tanks and you could have a hydrogen station. In a sudden oil crisis, trucking companies could set up hydrogen stations at every depot. They’d make the hydrogen overnight on off-peak electricity and then refill their trucks with it quickly. They probably would not need to store it for months, something petroleum doesn’t do very well anyway. (It can go off.) But the leaky pipes and corroded tanks and explosive potential all warn me off this as the fuel of choice.

5. Nitrous oxides in combustion engines

In a sudden oil crisis hydrogen combustion engines might even be considered. However, burning it in a hydrogen combustion engine could also release nitrous oxides which are a far more potent greenhouse gas than CO2. In a really sudden oil crisis I guess some trucking companies might be able to install hydrogen combustion engines in their trucks, and set up 4 times as many refuelling stations along the highways. But given the sheer energy involved in running all that, freight costs would soon escalate and I imagine this only being a temporary transport solution. The best option for busy long-haul trucking routes would probably be rail, even fast rail! The less frequented long-haul trucking routes would probably be replaced with synthetic diesel or boron.

6. Some more good reading:

So it is sheer madness to trust in a so called “hydrogen economy” when there are only a handful of hydrogen fuelling stations worldwide, the hydrogen fuel cell is an expensive technology relying on rare metals that will soon be depleted, the whole trillion dollar infrastructure will take far too long to implement, and it wastes so much energy! Let alone problems with hydrogen storage in the tank, domestic accidents, and the fact that it’s so difficult to transport hydrogen.

The Sanders Research Institute sums it up this way:

Even at the current level of activity, road traffic would consume more than 3 times all the electricity we generate to produce a hydrogen equivalent. With the end of North Sea gas looming and as the de-commissioning of nuclear power gets under way, electricity will be at a premium and only rail can make use of the limited amount of renewable electricity efficiently.

This is in stark contrast to reports that 70% of America’s cars could be charged from overnight off-peak electricity from today’s grid if America used full electric vehicles.

Based on research conducted by Pacific Northwest National Laboratories, this idle capacity in the U.S. grid could supply the equivalent energy needs of over 70% of the cars, trucks and SUVs that are on U.S. roads today – with no new utility system investment required! That’s approximately 175 million electric vehicles that today’s U.S. grid could support. However, achieving this requires the charging of EVs to be managed in a centralized fashion to ensure that charging takes place during “valley” (or “off-peak”) periods.
Via Better Place

So America can either build out 3 times the electricity infrastructure and then still have to build an expensive hydrogen economy infrastructure, OR it can just build about 30% to 40% more electricity supply and a few extra charging boxes at people’s work and homes. I would gladly pay the $500 to $1000 to have a charging box at home if it meant I was going to get all my transport energy for half the price of oil!

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