Grey goop that means a car can run on water

THE GREEN REVOLUTION: 1/5 Climate. Is hydrogen the key to fixing global warming? Research is speeding up, promising far lower costs than sceptics suppose. And the future scale is vast. A tube of paste that fuels a car. It’s a radical idea that could transform our world forever. Researchers in Germany call it powerpaste – a grey goop that generates electricity and replaces petrol without producing harmful CO2 emissions. And the magic ingredient is the most common element in the universe: hydrogen. Lighter than air, plentiful and powerful enough to send humans to the Moon – hydrogen has long been hailed as the future of energy. The chemical reaction in a fuel cell releases pure water instead of greenhouse gasses and so could help fight climate change. But until now, the high costs involved have held it back. Hydrogen does not exist on its own in nature. It must be separated from molecules using an energy-intensive process called electrolysis. And most hydrogen is not green but “dirty” – a product of fossil fuel refineries. But as the world aims for carbon neutrality, research accelerates to find cheap, clean and efficient ways to make hydrogen fuel work. Renewable energy will be key. Because wind farms and solar power cannot store energy, they waste anything that isn’t used. But by converting that excess into hydrogen, it can be stored for when demand is high, or supply is low. Island communities, rich in renewables but dependent on importing expensive fuel, are leading the way. But the real challenge is scaling up. A hydrogen society needs new infrastructure: power plants, pipelines, tankers and fueling stations. Analyst Ambrose Evans-Pritchard says the oil industry is meeting this need, “reinventing” itself as a supplier of zero-carbon fuel. Saudi Arabia is building a four-gigawatt hydrogen plant in the desert – the biggest in the world. Some are unconvinced. The entrepreneur Elon Musk calls hydrogen fuel “mind-bogglingly stupid”, asking why go to the trouble of turning green energy into liquid hydrogen and then back into electricity? We already have solar power, the electric grid and batteries. Why not just use electric cars? Energy analyst Rachel Fakhry says he may be right about cars, but there is about “15% of the economy” that is hard to electrify. Energy-intensive industries like “aviation, shipping, manufacturing, long-distance trucking“, where batteries are too weak and too slow to be effective. It is here that the most exciting developments are taking place, including a boat that runs on seawater and plans by Airbus to put hydrogen-fuelled planes in the sky within 15 years. A zero-emission plane would be a historic turning point. In 1937, the hydrogen-filled Hindenburg burst into flames, killing 36 people. Caught on camera, the disaster brought an end to the use of hydrogen in flight and hastened the rise of the jet engine. Companies are now keen to reassure us that hydrogen is both clean and safe. Toyota fired a bullet into one of its fuel cells to show that it would not ignite. And because hydrogen is lighter than air, it disperses away from the vehicle unlike petrol. Is hydrogen the key to global warming? Water into watts Some say no, it is a battle against the laws of physics, doomed to fail. Unlike renewables, it requires energy just to get the process started. Then it needs to be stored at 700 times atmospheric pressure or -253C, in special tanks that won’t weaken, leak or explode. And by the time it reaches our cars and homes, it has lost 70% of its energy. It is a waste of time and money. Others say yes, a hydrogen society is inevitable. As oil prices fall, the fossil fuel industry is transferring its skills to solve the problem of storing and moving hydrogen. Renewable energy is cheap to make where there are natural resources, but the green revolution needs a way to ship clean fuel to where it is needed. Hydrogen is the best way to store that green energy. KeywordsCarbon neutrality - When there is a balance between carbon emissions and the CO2 being removed from the atmosphere. It is also known as net zero.