How does hydrogen affect the environment?

The magnitude of the environmental gains possible through the use of hydrogen as an energy carrier depends on how the hydrogen is produced and transported, as well as how efficiently it is transformed. There are two primary areas where the environmental potential of hydrogen is especially significant: in transportation and as an interim storage of renewable energy.

Through the use of hydrogen together with fuel cell technology it is possible to achieve a radical decrease in local pollution of carbon dioxide, nitrogen oxides and particles from the transportation sector. Although the production of hydrogen from fossil fuels affects the environment it is an advantage that the carbon dioxide emissions can be separated already on the production site. This becomes evident when hydrogen is used as vehicle fuel, avoiding pollution from every individual vehicle.

The only emission from a fuel cell reacting with hydrogen is pure water. The environmental gains are high, provided that pollution in the hydrogen production process is kept low. A fuel cell is approximately twice as energy efficient as a combustion engine if used in a regular car. The effect is that, using the same amount of energy, a fuel cell car can drive twice as far as a car with a combustion engine can.

Modern batteries have even lower energy losses than those of fuel cells. However, these need to be recharged and are relatively heavy. Therefore, a combination of batteries and fuel cells can be advantageous in many areas, particularly in vehicles. For example, the reach of an electric car of family size is up to 500-600 kilometres of pollution free driving, since the fuel cells recharge the battery while the car is in use.

A growing part of the transportation sector is the use of fuel cells as APU (Auxiliary Power Unit). This kind of support power aggregate is used due to the large amounts of energy required to run cooling, air conditioning and other systems found in trucks. Today, this is mostly powered by small diesel engines or by idling the main engine, both of which create pollution and noise. The possibility of using hydrogen as APU in aircraft and large motorboats is also being explored.

Furthermore, hydrogen is expected to play a leading role as support in the development of renewable energy systems. Solar, wind and wave power are by their nature uneven sources of energy. Methods for interim storage are required in order for them to have any real consequence in the future. Here, hydrogen could even out the effect and function as storage for surplus energy. This would increase the flexibility of energy systems such as wind power, and help to accelerate the expansion of renewable energy.

Did you know that…?

• Bio-hythane is biogas blended with hydrogen (8-30% percent of the volume). It can be used in all gas vehicles resulting in improved drivability and decreased pollution.
• Fuel cell cars are a form of electric vehicles that are completely silent, reducing both pollution and roadway noise.