- The long journey from electricity back to electricity again!
- Chicken and egg
- Range issues
- Hard to store
- Nitrous oxides in combustion engines
- Some more good reading
1. The long journey from electricity back to electricity again
Hydrogen uses vastly more energy than batteries as an energy carrier. Each step uses energy. First we must split water to get clean, non-fossil fuel hydrogen. There’s a huge energy cost right there! Then we must freeze and compress the hydrogen to try and cram this gas into a tank. More energy wasted. Then we run it through a fuel cell which is only 40% efficient anyway, all to turn the hydrogen back into electricity to run the car! Why bother when a battery will do the job more efficiently? 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:
- Professor Chris Rhodes on Hydrogen requiring 60 new nukes, just for the UK.
- The Wiki on a Hydrogen economy
- The Future of the Hydrogen Economy: Bright or Bleak?
- On the Way to a Sustainable Energy Future (Text) and the presentation
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.
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