Hydrogen is being studied as a clean energy source to replace fossil fuels. Solar panels can be used to make hydrogen through a process called electrolysis. Different types of electrolysis methods are being researched, with alkaline electrolysis being the most common. Proton exchange membrane electrolysis is also promising for producing high-quality hydrogen. Solid oxide electrolysis is still in development, while anion exchange membrane electrolysis is in the early stages. Using solar panels to make hydrogen is seen as a key way to produce renewable hydrogen. Alkaline electrolysis is the most advanced method currently, but proton exchange membrane electrolysis is better at handling changes in solar panel output. Combining solar panels with electrolysis systems is a major focus for future research.