What is Green Energy?

Green energy is any energy type that is generated from natural resources, such as sunlight, wind, or water. As a source of energy, green energy often comes from renewable energy technologies such as solar energy, wind power, geothermal energy, biomass, and hydroelectric power.

What is hydrogen?

Hydrogen is the most abundant element on Earth - however there’s a catch. It doesn’t exist as a single atom. For example, even hydrogen gas is actually two hydrogen atoms bonded together (known as a hydrogen molecule, H2).

Hydrogen is known as an energy ‘carrier’ as opposed to an energy ‘source’. Energy carriers contain energy that can be converted to other forms - e.g. to power a vehicle. Before it can be used - hydrogen atoms must first be separated from a molecule containing hydrogen. The most common source molecule is water (H2O).

Hydrogen fuel cell technology

Hydrogen fuel cell technology has the potential to revolutionise the way we think about energy and transport in Aotearoa.

Emitting only water, vehicles powered by hydrogen fuel cells provide a clean alternative to petrol and diesel engines.

Find out about hydrogen technology and climate change.

How do fuel cells work?

At a basic level - hydrogen fuel cells convert chemical energy into electrical energy by converting hydrogen gas and oxygen into water.

Oxygen is readily available in the atmosphere, so it’s only necessary to supply the fuel cell with hydrogen.

To release the energy stored in hydrogen, every fuel cell needs three components:

1. Anode - where hydrogen enters and is stripped of electrons. These electrons are what generate electricity (power).
2. Electrolyte membrane - the positively charged hydrogen passes through the membrane to the cathode.
3. Cathode - oxygen enters the cathode and combines with hydrogen to form water.

Find out more about hydrogen fuel cells and how they work from the Fuel Cell and Hydrogen Energy Association.

Currently, the greatest challenge for hydrogen production, particularly from renewable resources, is providing hydrogen at a lower cost.