A Hydrogen Economy makes sense for supplanting Natural gas for Heating, and Electrical energy storage within a small country. But for farther distances you may have to turn to an Ammonia economy.

Missing link for solar hydrogen is... ammonia?

Ammonia (NH3) is key to enabling a solar hydrogen (H2) future, says a prominent Australian researcher.

From article, (Ammonia (NH3) is key to enabling a solar hydrogen (H2) future, says a prominent Australian researcher.

Solar energy could be stored, bottled and shipped globally in existing ammonia infrastructure as a zero carbon liquid fuel, according to Keith Lovegrove, the author or co-author of over 170 research papers and technical reports.

he said that a molecule that actually packs in more hydrogen than hydrogen (H2), holds the greatest potential to unleash a clean hydrogen economy. Ammonia (NH3) bonds together 1 nitrogen atom but 3 hydrogen atoms. "Amazingly enough, there's a greater mass of hydrogen in a liter of liquid ammonia than there is in a liter of liquid hydrogen," Lovegrove explained. "It's counterintuitive, but ammonia is just a better molecule at packing together with itself."

Perhaps, instead of the future H2 economy, we should really be planning for 'the NH3 economy' he suggested. Like hydrogen, with no carbon atoms, ammonia makes an ideal clean liquid fuel, but one with an easier transition.

"I'm personally in favor of using ammonia to transport hydrogen," he said. "You can then turn it into hydrogen when you get there. Or you can even use it directly, because with adapted conventional gas turbines, you can burn ammonia directly."

H2 and NH3 can both store and carry energy, but ammonia is more ideal as an energy carrier, he said. "Ammonia production for fertilizer is one of the world's biggest chemical industries. There's plants all over the world, and ships moving it about on a daily basis, so it's a very standard thing."

Because it is already widely produced and used, with well established distribution and handling procedures, it wouldn't be a difficult transition. When ammonia is burnt as a fuel it simply returns to nitrogen and water. If it leaks into the air, it is easily detected by smell.

Liquid fuels are the largest untapped source for decarbonization. Even if all the electricity in the world was 100% renewable, the entire electricity sector currently accounts for only 20% of global emissions.

Thirty years of trying has not brought the solar hydrogen economy to fruition, mostly because hydrogen entails new infrastructure to transport and store it. Researchers are increasingly looking at ammonia, with shipping and containing infrastructure in place, as a potential carrier.

Ammonia can not only store and ship renewable energy, it can also be made using any renewable source of electricity.

Because Ammonia is simply hydrogen and nitrogen, it can be split chemically from just water (H2O) and air (73% nitrogen) using electricity. Any chemical reaction is basically the exchange of electrons between atoms. Hydrogen (H2) - which does not occur in nature - can be split out of water (H2O) leaving oxygen. In ammonia; NH3, each atom of nitrogen holds three hydrogen atoms.

To chemically rearrange these molecules, readily available electrolysis can be supplied by electricity from any renewable energy source already.

"You can walk up to Siemens for example, and you can buy a multi-megawatt electrolyzer straight away. It's commercially available, so you can just put that onto a PV farm. You can do that tomorrow morning," said Lovegrove.

In any region globally where renewable electricity costs are $30 USD per MWh or less, solar or wind electrolysis would be competitive with natural gas-based ammonia production, which emits 1.7 tons of CO2 per ton and costs between $200 and $600 per ton, according to the IEA: Renewable Energy for Industry.)