http://www.ck12.org Chapter 3. Making A Difference
Figure 20.25:The Hummer H2H: embracing the green revolution, the American way. Photo courtesy of General
Motors.
The “hydrogen economy” received support fromNaturemagazine in a column praising California Governor Arnold
Schwarzenegger for filling up a hydrogen-powered Hummer (figure 20.25). Nature’s article lauded Arnold’s vision
of hydrogen-powered cars replacing “polluting models” with the quote “the governor is a real-life climate action
hero.” But the critical question that needs to be asked when such hydrogen heroism is on display is “where is the
energyto come from tomakethe hydrogen?” Moreover, converting energy to and from hydrogen can only be done
inefficiently – at least, with today’s technology.
Here are some numbers.
- In the CUTE (Clean Urban Transport for Europe) project, which was intended to demonstrate the feasibility
and reliability of fuelcell buses and hydrogen technology, fuelling the hydrogen buses required between 80%
and 200%moreenergy than the baseline diesel bus. - Fuelling theHydrogen 7, the hydrogen-powered car made by BMW, requires 254 kWh per 100 km –220%
moreenergy than an average European car.
Figure 20.26:BMW Hydrogen 7. Energy consumption: 254 kWh per 100 km. Photo from BMW.
If our task were “please stop using fossil fuels for transport, allowing your-self the assumption thatinfinitequantities
of green electricity are available for free,” then of course an energy-profligate transport solution like hydrogen might
be a contender (though hydrogen faces other problems). Butgreen electricity is not free. Indeed, getting green
electricity on the scale of our current consumption is going to be very challenging. The fossil fuel challenge is an
energy challenge. The climate-change problem is an energy problem. We need to focus on solutions that use less
energy, not “solutions” that use more!I know of no form of land transport whose energy consumption is worse than