Types of hydrogen power
Hydrogen is a way of storing energy easily. The main ways of using hydrogen as a fuel is either by burning it or using it in a fuel cell to make electricity. Using hydrogen as an energy source is only renewable is produced from a renewable source.
How does it work?
Burning hydrogen can produce power in the same way as burning fossil fuels does, by making steam to turn a turbine and generate electricity.
Fuel cells behave more like a battery. Hydrogen fuel reacts with oxygen in the air to produce water molecules. The reaction involves transfer of electrons and by making these electrons flow round a circuit, we can produce electricity.
Hydrogen gas needs to be made for these uses as it is reactive and does not hang around as a gas for very long. It can be produced from fossil fuels or by splitting water into oxygen and hydrogen using electricity. Some biological organisms also release it.
Costs and efficiency
Hydrogen can be costly to produce and store. A fuel cell in a car is about 40% efficient at the moment. The energy process to produce hydrogen and then use it again to make electricity involve energy losses, greater than directly powering electric vehicles so efficiency is lower. However, it give us the opportunity to avoid fossil fuels is we can produce hydrogen from renewables.
Fuel cells are relatively small and fit into a car. Burning hydrogen requires a power station.
Locations around the world
The main use of hydrogen fuel cells thus far is for decreasing our reliance on fossil fuels for transportation. Therefore, they are likely to be found everywhere. Several places around the world are starting to invest in hydrogen-powered buses and cars.
Burning hydrogen only produces water and does not produce carbon dioxide, if the hydrogen is made using a renewable source rather than fossil fuels.
Hydrogen gas is a reactive gas that is very flammable. To produce it uses fossil fuels, or involves electricity to split water. However, if the electricity could be provided by other renewable sources of power, this would help.
Hydrogen gas takes up a lot of space and could be prone to leakage. Storing it as a liquid involves compressing the gas which is costly and involves high pressures. There are also ways of storing it in solid form by using materials that absorb it like a sponge. These are often heavy.
There are concerns that burning hydrogen in air can cause some unwanted chemicals that are bad for the environment. For example, if hydrogen combines with nitrogen and carbon, it can make cyanide. Hydrogen leakage could also have effects, especially if it reacts.
Hydrogen is very explosive so if it leaks, it could prove a hazard.
Scientists and engineers are mainly trying to improve the efficiency and performance of hydrogen fuel cells and tackle the problems of hydrogen production and storage so that they can become a more viable option for powering vehicles. Other types of fuel cells that use methanol instead of hydrogen are also being made and tested. Methanol is a much easier fuel to store as it is a liquid, but it does contain some carbon so would produce some carbon dioxide if it was used.
- SUPERGEN Fuel Cells
- UK Sustainable Hydrogen
- Fuel cells
- Fuel Cell Bus Club
- Fuel Cell Markets
- Hydrogen Economy