As the ABC explains, electrons are the tiny particles that make up your electricity. Your TV, laptop and microwave get their power from electrons as they whiz down a cable. Green electrons are simply electrons that were made using renewable resources – the wind or sun, for example.
So: if you charge your electric car using electrons made by burning fossil fuels, you’re indirectly driving global warming – but if you use green electrons, your car is truly zero-emissions.
Let’s take one step back to atoms. Atoms are the tiny building blocks that make up everything around you. A molecule is basically lots of atoms bound together. For example, water is a “molecule” made up of two hydrogen atoms and one oxygen atom.
A “green molecule” is basically a molecule that has been made using green electrons. Green hydrogen is the most obvious example of a green molecule. To make it, you run green electrons through water, which splits it into hydrogen gas (two hydrogen atoms bound together) and oxygen.
Green hydrogen is the basis for a range of other “green molecules” – including green ammonia (green hydrogen combined with nitrogen). Green hydrogen can also be combined with carbon to make synthetic methane and methanol – but these are only “green” molecules if the carbon is closely guarded along the supply chain and recycled.
So: why are green molecules going to be critical?
Today, electricity provides around 20 per cent of all global energy use – the remaining 80 per cent of energy we consume comes in the form of “molecules,” mainly fossil fuels like coal, oil and gas.
While electrification will rise, not every industry can simply be “plugged in.” Many of our most important industries – like planes, shipping, trucking, steel, and fertiliser – currently rely on molecules and will require green molecules, not green electrons, to decarbonise.
Green molecules are critical for other reasons.
By turning green electrons into green molecules, you can “store” the energy cheaply – rather than wasting it or having to store it in a battery. Many green molecules can be shipped on existing industrial ships and piped in existing pipelines. Laying electric cables works for short distances (for example, Europe may import green electrons from North Africa via seabed cables) but green hydrogen will enable a truly global energy trade – and will be a lifeline for countries with limited renewable resources, who need to import their green energy.
With seven years left for the world to almost halve its greenhouse gas emissions, green molecules provide a solution that can scale quickly. It’s not an “us” vs “them” situation either – we will need both green electrons and green molecules.