Five Percent: Conserve Energy

Climate Change Is Important: Energy Conservation is the First Step


June 19, 2006

Hydrogen Fuel Cells: Fantastic Batteries … Not Energy

Category: Companies,Conservation,Economics,Policy,Transportation – Tom Harrison – 11:57 pm

A lot of talk, especially a few years ago, planted the notion that fuel cells, and the “Hydrogen Economy” were the panacea for our energy and global warming woes. Perhaps President Bush is helping us remember these feelings in his famous “addicted to oil” comment from the State of the Union Address:

Keeping America competitive requires affordable energy. And here we have a serious problem: America is addicted to oil, which is often imported from unstable parts of the world. The best way to break this addiction is through technology. Since 2001, we have spent nearly $10 billion to develop cleaner, cheaper, and more reliable alternative energy sources — and we are on the threshold of incredible advances.

Which incredible advances, and how wide a threshold is left to the imagination. But one important point: hydrogen fuel cells are not a source of energy, they are a means to store energy for use on demand, just like batteries. Very good batteries, very cool technology, and a very, very important key to how we transition away from oil, to be sure. But oil, gas and coal can be pumped or dug up relatively inexpensively, converted a little and be in a form to have it’s energy released. And while hydrogen as part of a compound, like water, is plentiful, hydrogen as a free-standing molecule (which is what we need) is almost non-existent. You need energy to make it.

In order to make the clean burning fuel whose only by-product is water, we first need to separate the hydrogen from it’s normal resting place. And the easiest and most obvious resting place is … water. It’s easy to do with electrolysis — I did it in my 7th grade science class. Only one problem: you need to add electricity to get the H’s unstuck from those O’s. And, almost all of our electricity (in the US) comes from coal, natural gas, nuclear, some (about 10%) from oil, and the paltry rest from wind, solar, hydro, geothermal, and hamsters.

It will still take years to build up the huge infrastructure needed to support manufacture, storage, distribution supply chains for hydrogen, and to build practical vehicles that use it. Predictions of 10 to 20 years are the norm, now, and even if realistic, we have some more immediate issues to deal with in the relatively short term.

But now that I have slammed hydrogen, there are some really important points to make, because there are some valid reasons that people think fuel cells are destined to be a key to our next primary energy platform.

First, as I have been discovering while reading 1000 Barrels A Second if you’re worried in any way about the geopolitical ramifications of our current energy related issues, it seems pretty clear that oil is going to get expensive pretty soon (if you think it’s expensive now, wait). Energy sources like coal are readily available still, and nuclear is certainly something we can do, but both only make electricity; they’re not good for directly powering things that move, unless you are thinking of resurrecting the steam engine. So even if we do have to burn coal or make more nuclear plants, this gets us electricity. And we can use that to make hydrogen.

Second, electricity is paradoxically not very portable. If you make electricity at one place, the further you transmit it, the more energy is lost in the process; it travels fast, but not very well over long distances. Plus, the cord (or power lines) are very limiting. But it is the inability to store electricity that is the real kicker — batteries are our only large-scale means of storing electricity, and they do a poor job of it. Oil, in the form of gasoline, jet fuel or diesel are all very dense and practical forms of storing energy: it’s liquid so easy to store and move, it’s relatively light, it doesn’t get stale, and it’s easy to get energy from it by burning it in an engine. Fuel cells, however, largely address this: they can be small or large as needed to suit the application. So fuel cells allow us to store the fuel in a relatively familiar form (compressed gas, like a gas grill), and this makes a portable way of producing electricity.

Third, fuel cells can work in reverse: if you give them electricity they make hydrogen and oxygen. One source of electricity is the same used by my hybrid car: regeneration of electricity from braking or going downhill. And while electricity is not very portable, it is ubiquitous, so yes, you should also be able to plug in your car at night. While over the long run it will make more sense for centralized, efficient plants to manufacture hydrogen, and efficient transportation networks to deliver it to local filling stations, electricity is not a new thing, either for cars or other applications, and it is very, very flexible. There are multiple options with hybrid technologies: electricity from a fuel cell gets you to most places, with gasoline available for the long runs?

Fourth, is another electricity paradox. We don’t have an over-supply of electricity right now, and a lot of the supply infrastructure (the “grid”) is fragile, as the blackout in the Northeast US several years ago demonstrated. But the truth is, the real, pressing demand for energy today is oil because it’s the best solution for transportation. Because electricity can be made, and used, in many ways, increased demand should stimulate investment in the infrastructure — not just in building more generation plants, but in increasing the capacity and reliability of the existing transmission grid. If we can store electricity for use in cars, with fuel cells, and if we can store electricity generated from other sources in fuel cells we have a “buffer” that makes some electricity generating applications practical. Wind and solar power both produce electricity, but often not really where the power is needed; the loss of power over distance when electricity is transmitted over wires limits the applications of some larger-scale applications.

Fifth, decentralized production of energy is a good thing. As we rely on fewer and fewer oil wells, in less and less attractive of friendly places, the importance of decentralization and storage becomes clear. But today we think big and centralized: a big oil company has some wells that get refined in a few refineries and distributed locally by pipeline or truck. Or a big electricity generating plant serving a wide area. These things tend to crowd out the incremental value in generating small amounts of energy. Smaller, contained, independent systems (like a car) provide some of the same benefits as the decentralized structure of the Internet: safety and reliability through redundancy, and the opportunity to contribute a little or a lot on a relatively more even playing field should tends to lead to innovation and a broadening of suppliers. Because the incremental infrastructure is cheap, and because the commodity is standardized, the barriers to entry should be lower.

So we still have to get ourselves out of a rather serious short-term bind. And in the medium-term, things won’t be pretty for the environment as we burn even more coal, build nuclear plants and lower quality oil. But if we come out the other side alive, the hope of a dramatically better source of portable energy provides some hope that the world as we know it may actually live to tell the tale.

Until then, you might consider whether you really do need that SUV.

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