Hydrogen: folly or fuel of the future?

© Honda

The title of this post has been changed.

When I last wrote about hydrogen powered cars vs electric cars, there were 253 comments saying, “This is a horrible article with an extremely visible bias. Did Elon Musk pay the writer?” I sometimes feel lonely and depressed when I write about it, especially when I get “Total BS article. You have no idea what you are talking about.”

Fortunately I have reinforcement from Lance Turner, who writes in Australia’s wonderful Renew Magazine and asks, "Hydrogen as a fuel- Is it really viable?" He comes up with many more reasons to be doubtful than I ever did.

Lance starts with a good explanation of how hydrogen powered cars work:

In a fuel cell vehicle, hydrogen is stored in high-pressure tanks and delivered to the fuel cell at a reduced pressure, while air is passed through the fuel cell stack (the common term for a number of fuel cells in a single unit) courtesy of an electrically driven compressor system. By varying the rate of gas flow through the stack, the electrical output of the fuel cell system can be controlled.

Toyota mirai© Toyota

He then points out that hydrogen powered cars are not really that different than electric cars; they still have a battery or an ultracapacitor to store the energy that comes from the fuel cell (which does not respond quickly enough to the accelerator pedal), which then drives the motor.

The hydrogen is stored at high pressure (700 atmospheres or 10,000 PSI). The tanks are expensive, and are made from carbon fibre composites because metal would be too heavy. Even so, the weight of the hydrogen that the tank stores in the Toyota Mirai weighs 87.5 kg in total and yet hold just 5 kg of hydrogen. Some people are nervous about what happens in a crash.

It takes a lot of energy to compress the hydrogen, “as much as 20 percent of the total energy stored in the hydrogen.” Compressing it generates heat, so it has to be cooled during compression, using yet more energy.

It’s really just reformed natural gas

steam reforminghow you make hydrogen from natural gas/Screen capture

Almost all the hydrogen available today is made by steam reformation of a good old fossil fuel, natural gas. “This requires a lot of energy to do, in fact more energy than you can recover from the resulting hydrogen that’s produced.”

Filling stations are really expensive to build (and there aren’t many of them.)

Toyota Mirai hydrogen fuel station© Toyota

They cost about a million bucks each. Compare that to Sami’s electric outlet on a stick that can go anywhere.

The overall efficiency of the whole system is low.

The overall fuel cycle efficiency of hydrogen generation transport and use in vehicles is rather low compared to electricity transmission and battery charging in EVs. Quoted figures vary depending on who you ask, but the overall efficiency for a fuel cell vehicle, from well to wheel, is about 30 percent due to the aforementioned issues of gas compression and cooling, the relatively low efficiency of hydrogen production and the efficiency of the fuel cells themselves.

There are a few advantages.

They fill up fast like a gasoline car, no waiting around for a charge (but no filling up at night at home, either.) Scientists are developing better, more efficient ways of separating hydrogen from water than conventional electrolysis. There is a lot of solar capacity coming on line that might make hydrogen useful as a way of storing excess power.

But electrochemical batteries are getting better all the time and are being used for storage at industrial scales now; and people are putting solar panels on their houses and can charge their cars up almost for free.

Who's really driving the hydrogen car?

Hydrogen Council Hydrogen Council/Screen capture

For years I suggested that hydrogen cars were really just a shill for the nuclear industry, which saw them as a way of creating significant demand for their electricity. Now it’s the gas industry. At Davos this year, a consortium of car companies and fossil fuel companies formed the Hydrogen Council to position "hydrogen among the key solutions of the energy transition.” They will turn their natural gas into hydrogen which they say "does not release any CO2 at the point of use" because it is released at the refinery, not the tailpipe.

Daniel Cooper wrote in Engadget:

The reasons why these companies are teaming up around hydrogen isn't about saving the planet, but maintaining relevancy. After all, electric cars require far less infrastructure investment than hydrogen and can be significantly cleaner. Not to mention that EVs aren't directly contributing to oil and gas companies' bottom lines.

This is why we have hydrogen powered cars -- to provide another market for all that natural gas, and to keep centralized control of the fuel among the big fossil fuel companies. There is no other reason to even bother.

Tags: Alternative Fuels | Fuel Cells


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