The idea of a “hydrogen economy” is now enjoying a new wave of enthusiasm — but it is not a silver bullet. Amid the current hydrogen hype, there is little discussion about when the technology can realistically become commercially viable or the best ways it can be used to cut emissions. Australia must use hydrogen intelligently and strategically. Otherwise, we risk supporting a comparatively energy-intensive technology in uses that don’t make sense. This would waste valuable renewable energy resources and land space, increase costs for Australians, and slow emissions reduction. Here’s where we can focus hydrogen investment to get the best bang for our buck. A poorly targeted hydrogen strategy will slow emissions reduction. Tridsanu Thophet / EyeEm / Getty Images HYDROGEN SUCKS UP ENERGY AND SPACE Hydrogen is the most abundant element in the universe but rarely is it freely available. It must be unlocked from water (H2O) or fossil fuels such as methane (CH4), then compressed for transport and use. These steps waste a lot of energy. To be transported, for example, hydrogen must be kept under high pressure or extremely low temperature. And in terms of energy storage, even heating up stones is more efficient. Australia could become a renewable energy superpower in the future. But there are serious medium-term challenges, including constraints in the infrastructure that transmits energy. The world must reach net-zero emissions within 30 years to avert the worst climate change. That means using renewable energy as efficiently as possible to maximize emissions reductions and minimize the land space required. So we must be strategic in how and where we use hydrogen. Hydrogen pathways. Staffell et al 2018. The role of hydrogen and fuel cells in the global energy system. USE HYDROGEN IN PLACES ELECTRICITY WON’T GO In most applications, renewables-based electrification has emerged as the most energy-efficient, and cost-effective way to strip emissions from the economy. Yet there are some industries where electrification will remain challenging. It’s here renewable hydrogen — produced from wind and solar energy — will be most important. These industries include steel, cement, aluminum, shipping, and aviation. A renewable hydrogen export market may also emerge in the long-term. Renewable hydrogen will also be important to replace existing hydrogen produced by fossil fuels. But this alone will require a significant increase in electricity generation, to reach net-zero emissions by 2050. This is a major challenge. Australia’s renewable energy capacity would need to increase substantially to produce green hydrogen. Mint Images / Getty Images WHAT ABOUT CARS AND TRUCKS? Road transport is one area where we believe hydrogen will not play a major role. In fact, Telsa founder Elon Musk has gone as far as to call hydrogen fuel-cell vehicles “mind-bogglingly stupid”. Hydrogen vehicles will always consume two to four times more energy than battery electric vehicles. This is simply due to the laws of physics, and cannot be resolved by technological improvements. In the case of hydrogen-powered vehicles, this will mean higher costs for consumers compared to battery-electric vehicles. It also means far more space for solar panels or wind turbines is needed to generate renewable energy. What’s more, electric vehicles already have a longer driving range and continuously expanding charging infrastructure, including ultra-fast chargers. Comparing the amount of electricity that is lost for hydrogen cars versus electric cars. Volkswagen AG Most global carmakers have recognized the lack of advantage for hydrogen cars and instead invested about US$300 billion in the development and manufacturing of electric cars. Toyota and Hyundai — the last main proponents of hydrogen cars — are also ramping up efforts on electric cars. As fo