Practice Tests
IELTS Reading (AC) Task 1 #161

A. Green hydrogen is a form of hydrogen produced using renewable energy to split water into hydrogen and oxygen through a process called electrolysis. Unlike "grey" hydrogen, which is produced from natural gas and is highly carbon-intensive, or "blue" hydrogen, where the carbon emissions are captured, green hydrogen is a completely carbon-free energy carrier. This makes it a highly promising tool in the global effort to decarbonise sectors of the economy that are difficult to electrify directly.

B. The production of green hydrogen is conceptually simple: an electrolyser, powered by electricity from renewable sources like wind or solar, passes a current through water (H2O), breaking it down into its constituent elements. The hydrogen gas can then be stored, transported, and used as a clean fuel. The only by-product of this process is oxygen, which can be safely released into the atmosphere or captured for industrial use.

C. The potential applications for green hydrogen are vast, particularly in heavy industry and long-distance transport. It can replace fossil fuels in industrial processes that require high heat, such as steel and cement manufacturing. In transportation, it can be used in fuel cells to power heavy-duty trucks, ships, and potentially aircraft, which are difficult to power with batteries due to weight and range limitations. It can also be stored for long periods and converted back into electricity, helping to balance power grids that rely on intermittent renewable sources.

D. The primary barrier to the widespread adoption of green hydrogen has been its high cost compared to fossil fuel-based alternatives. The cost is largely determined by the price of renewable electricity and the efficiency of electrolysers. However, as the cost of solar and wind power continues to fall and electrolysis technology improves, green hydrogen is projected to become economically competitive in the coming decade. Significant investment in infrastructure for production, storage, and transport will be necessary to unlock its full potential as a cornerstone of a future clean energy system.