Researchers at Purdue University are using the Earth's abundant supply of aluminum to develop a method that creates electricity -- and even potable water. I spoke this week with Jerry Woodall, a professor of electrical and computer engineering. Below are excerpts from our interview.
How does the aluminum alloy that you developed create hydrogen to generate electricity?
Aluminum is a very stable metal. It will dissolve into liquid gallium. When the aluminum goes into the gallium, it will freely react with water. When it gets to the interface between the gallium and the water, it will take a water molecule and split it off into hydrogen gas and aluminum hydroxide. The reaction gives off heat, but the reaction also gives off hydrogen and aluminum tri-hydroxide.
I can make hydrogen on demand from something that is safe. Aluminum is very safe. It's the third-most abundant element on the planet's surface, so there's no sustainability issue. Once you buy a piece of aluminum, it's yours forever. You can recycle this thing over and over again.
In what situations could this be used?
There are plenty of people off the grid right here in the United States. Where this makes sense is where you do not have grid electricity. It's great for military operations. You wouldn't have to put in a road. You wouldn't have to put in electric transmission lines. This could be dropped in with a helicopter. It will be very economical to do it this way. Countries that have a lot of remote villages with no electricity, this makes great sense for them. Not only do you get electricity, you get potable water.
Why is this better than other methods of generating electricity?
It costs a lot of money and infrastructure to put in grids to places that are small. If you look at it economically, it makes more sense to supply the chemical energy to village that needs it. They can get water and electricity without having to put in electric lines. I'm in a town with plenty of electricity, but if the grid goes down I can use this as a space heater and to supply electricity. I can use it for emergency backup power.
What's the next step?
We've spent the last five years perfecting this aluminum alloy that works every time. [For the near term, I'm excited about this for] off-grid electric power and potable water for places that need it. The other one is for backup power, so you don't freeze in the winter if the power goes down. We can supply both heat and electricity. There are very few systems that will do that. We can make electricity because we have the hydrogen to do it.
You discovered this in 1968. What's it like for this work to now come to fruition?
Let's not make it that glamorous. Back in 1968, I was working on something else and I discovered it. We did a patent on it. But my day job then was to make compound semiconductor materials for the electronics industry. This thing sat dormant until about 2005. I decided I'd take a look at it again because people were getting cranked up about alternative energy and green energy. What I want to work on, it's got to be economically viable and it's got to be sustainable.
Photo, top: Chunks of aluminum alloys used to split water to make hydrogen, heat and aluminum hydroxide
Photo, bottom: Jerry Woodall