Skip to 0 minutes and 4 secondsOK, our colleagues are talking about chemical fuels like ammonia and hydrogen, splitting water, and so on. Potentially, these storage and fuels could be much better than batteries. Of course, you know the amount of storage you get into a fuel could be up to 100 times more than a battery. So where do you see batteries versus fuels? Where do you see that argument going? An interesting question. I think, as I said before, horses for courses. No one technology is going to solve all the problems. So there are situations where chemical fuel will be much more / a better option than batteries. And that might be energy storage applications.

Skip to 0 minutes and 47 secondsIt could even potentially be, for example, in a fuel cell car, like a Honda. And Toyota, for example, is making a fuel cell car. But that fuel cell car still has a battery in it. It's really a hybrid. So there will always be a place for batteries, even if chemical fuels do take off. We've got to solve a lot of problems with chemical fuels, still. We've got to solve the catalyst problem. We've got to solve-- everyone's doing it small scale, but to demonstrate it on a larger scale, cost-effectively, the catalysts are quite expensive-- platinum for fuel cell cars.

Skip to 1 minute and 21 secondsI think the future will see chemical fuels, but there will be a place for chemical fuels alongside batteries, depending on the application you're looking at.

Solar fuels versus batteries

We have now seen that we can store energy in either a solar fuel or battery. Which would be a better option for a sustainable future?

As Prof. Maria Forsyth suggests in the video the answer is not straight forward. The energy storage capability of batteries and fuels are;

Lithium-Ion Batteries - 0.2 kWh/kg

Liquid H2 fuel - 39 kWh/kg - (2.3 kWh/L)

Liquid Ammonia NH3 - 7.2 kWh/kg - (4.3 kWh/L)

So it appears that H2 would be much better for storage that you would have to carry around like in a car. But splitting water produces H2 gas that takes up a lot of space and needs to be compressed to a liquid. However, this compression takes an energy cost.

Those are just a few of the considerations. We also have to think about the materials we use to make the batteries, how much waste we generate, how much C02 we produce.

Conversation Starter

How do you think that we can use solar fuel and batteries to provide energy for the world in the way coal, gas or nuclear power plants do?

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How to Survive on Earth: Energy Materials for a Sustainable Future

University of Wollongong

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