Fuel for Thought, Part 1: Biofuels and Fuel Cells

Jonathan Strickland

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What's the future of fuel? How are we going to power the amazing future we talk about in Fw:Thinking? Our need for fuel -- whether it's to provide electricity or power our vehicles -- grows every year. Back in 2011, the United States consumed 134 billion gallons of gas, which averages out to just over 367 million gallons per day. We're using oil, coal and natural gas to generate power while also adding greenhouse gases and other toxins to the environment.

We don't seem to be in any immediate danger of running out of fossil fuels -- we've discovered new reserves and new ways to get at fuel that was previously inaccessible. But while things may be fine now, we'll eventually use up the fossil fuel that's available. Since fossil fuels take millions of years to go from dead stuff to usable fuel, that's a problem. And the mounting concerns for the environment and climate change add to that problem. Sooner or later, we have to find an alternative.

We can look to solutions like biofuels such as biodiesel or ethanol to help offset our needs. But as I explained in an earlier blog post, we produce a fraction of the biofuels we'd need to replace our gasoline consumption. Plus, biofuel production comes with its own host of environmental problems and could also reduce biodiversity. Less biodiversity increases the chance for a disease to wipe out an entire crop of plants we intended to use as fuel. Besides, right now we're mixing gasoline or petroleum-based diesel with biofuels, meaning we're just stretching how far a gallon of petroleum-based fuel will go.

I really do think electricity is where we'll turn to, at least in the short term. But we still need to generate electricity in a clean way if we want to reduce greenhouse gas emissions and other environmentally harmful products. While solar cells, wind turbines and hydropower might help in some locations, it'd be challenging (or maybe even impossible) to scale up production to meet the energy needs of a city, let alone an entire country. But let's look at some clean ways to generate electricity.

Fuel cells are an attractive alternative. A hydrogen-based fuel cell brings hydrogen and oxygen together in a process that generates three main products: electricity, water vapor and heat. A membrane separates the hydrogen and oxygen. The hydrogen must ionize, giving up its electrons, before it can pass through the membrane to join up with oxygen for a pool party on the other side. The free electrons pass through a circuit, doing work along the way, before rejoining the water molecules on the other side. Sounds great, right?

You knew there'd be a catch, and it's a big one. Hydrogen isn't easy to come by. That might surprise you, seeing as how hydrogen is the most plentiful element in the universe. But hydrogen on Earth bonds with lots of stuff, meaning we don't have massive pockets of pure hydrogen we can tap into for our fuel cells. To get at the hydrogen, we first must expend energy to free it from its molecular bonds. If the energy you use to free hydrogen comes from burning fossil fuels, you've really just shifted the fossil fuel problem to a different part of the equation.

If we could find an efficient way to get hydrogen using solar, wind or some other renewable energy source, a hydrogen-based fuel cell would be fantastic. The hydrogen becomes an energy storage unit. You could power your electric car, knowing that your vehicle isn't emitting harmful gases into the atmosphere. In this idealistic scenario we also assume that our method of harvesting hydrogen isn't also creating other harmful byproducts -- otherwise, we're back at square one.

There's way too much to write about in one blog post. In the second post, I'll cover the topics of fission and fusion -- harnessing nuclear processes to generate electricity.