 Limiting the global temperature rise below 1.5 degree Celsius is essential to avoid the worst impacts of climate change. Reducing greenhouse gases like carbon dioxide is important to achieve these aims. It is not possible to electrify everything and alternate fuel options based on renewable energy are required. Hydrogen is an attractive candidate for carbon-free fuel as it can be produced in a variety of ways and has a lot of energy and industrial applications. Hydrogen combines with oxygen to produce water or water vapor as a by-product when used, meaning that there are no greenhouse gas emissions as long as it is produced using renewable energy. Unfortunately, hydrogen is currently produced using fossil fuel technologies which release a lot of greenhouse gas emissions. Renewable methods like electrolysis split water into hydrogen and oxygen using renewable electricity options such as wind and solar. At the moment, this is still too expensive and researchers are looking for ways to make it cheaper. Given the vast pool of applications of hydrogen, it is important to focus on techniques to produce low-cost, large-scale renewable hydrogen generation. This is the solar simulator and is an important part of this research. It has a lamp inside which is calibrated to provide a slide similar to what we received from the sun. And this is the lab where I work with Dr. Fiona Beck on direct solar hydrogen generation. Our research at the Australian National University focuses on direct solar hydrogen generation systems using low-cost materials and existing solar cell technologies combined into one system to produce hydrogen cheaply and efficiently. Our system combines the current silicon solar cell technologies used to produce electrical energy from sunlight directly with catalyst-coated electrodes where the water-splitting reaction happens. Our system achieved a direct solar-to-hydrogen conversion efficiency of 20% meaning one-fifth of the sun's total energy is converted and stored as chemical energy in the form of hydrogen. This system also achieved the US Department of Energy Solar-to-Hydrogen Efficiency Target for direct solar hydrogen generation systems to make them economically viable for large-scale hydrogen generation. For the widespread applications of hydrogen to flourish and drive down the greenhouse gas emissions, we need cheap and renewable hydrogen. Direct solar hydrogen generation could potentially provide a low-cost pathway towards hydrogen generation if we can continue to improve the efficiency and lower down the system cost. And it is a goal worth pursuing. If we can quickly scale up renewable hydrogen generation, it can provide one-fifth of the reduction needed to reach the net zero emissions by 2050 and keep the global temperature rise to below 1.5 degree Celsius.