Edits are being done on the Renewable energy page. Here is the section I worked on

Hydrogen[edit]

Hydrogen is the most abundant element in the universe, and the heat released per unit mass is three times more than gasoline ^[1]. Current renewable energy sources like Hydropower, Wind, Solar, and Geothermal energy have limitations in maximizing energy for human life due to geographical or technological reasons. Hydrogen is the latest energy source studied as a potential energy carrier. The benefits of hydrogen energy include its lightweight, widespread availability on Earth and lack of emissions when used as fuel. Hydrogen can be produced by domestic sources, reducing reliance on overseas energy sources. ^[2]

There are three main classes of hydrogen energy: gray, blue, and green. Hydrogen is classified as gray hydrogen when made using fossil fuels such as coal and oil, resulting in greenhouse gas emissions. Gray hydrogen production typically uses thermal, cracking, pyrolysis, and gasification methods. ^[3] Blue hydrogen comes from natural gas, biogas, and syngas, which creates carbon emissions that are then captured and reused. Blue hydrogen uses steam reforming, auto-thermal reforming, and combustion technology. Green hydrogen is produced using renewable energy like solar and has zero emissions. Green hydrogen comes from using electrolysis, thermolysis, and biophotolysis technologies. ^[3]

Limitations[edit]

One drawback to using hydrogen as a fuel is that it must be in the pure form of hydrogen to produce energy. ^[1] Hydrogen needs tremendous efforts concerning its commercial viability to be a primary energy source. The current progress of hydrogen is that 96 percent of hydrogen comes from steam reforming methods; another 4% of hydrogen comes from electrolysis methods. Steam reforming technology is the best method of extracting hydrogen from fossil fuel stocks. In the United States, 10-11 million tons of hydrogen is produced from steam reforming yearly instead of using green hydrogen production. ^[2]

Additional limitations of Hydrogen energy include capital costs, hydrogen production costs, water and rare material consumption, systems efficiency, and durability. Installations are costly; small builds of 0.3-5 kW cost around 10,000 EUR/kW. ^[4] Larger builds go up to 2000 to 3000 EUR/kW. Technological advances in the research of hydrogen production are required to lower the cost of production and efforts to gain benefits from this form of energy. ^[4]

This user is a student editor in University_of_Washington/Geographies_of_Energy_and_Sustainability_(WIN_2024). sandboxes