The use of fuel cells to produce energy is still quite a new concept. Although NASA has been using fuel cells in their space shuttles since the 1960s, the technology has only been applied to road vehicles and home appliances in the last few years. As our understanding of fuel cells increases, they could be used in many more industries in the future.
Electrical energy is released from hydrogen fuel cells. Electricity can be used to power a whole range of appliances and vehicles.
The electricity in a fuel cell is created by applying hydrogen to the anode and oxygen to the cathode. A catalyst splits the hydrogen into positive ions and negatively charged electrons, the latter of which travel along a circuit to the cathode. This is how the electrical current is created.
The most important benefit of fuel cells is that they can produce electricity with zero emissions. The only byproducts are heat and water. These do not harm the planet like the emissions that are produced by fossil fuel-powered vehicles and devices, such as carbon monoxide, sulphur dioxide and nitrogen oxide. The water that was created by the alkali fuel cells in NASA’s Apollo spacecraft was clean enough for the astronauts to drink.
Although fuel cells don’t produce any pollutants, some are created during the production of hydrogen in order to fuel the cells. Where possible, hydrogen should be created using renewable energy, such as solar and wind power, in order to keep CO2 production to a minimum. In some cases, this could mean that you can power the boiler in your home using only renewable energy.
There are lots of types of fuel cells that are named according to the kind of electrolyte that is used to create the electricity. Each one can maintain different levels of efficiency, work at varying operating temperatures and has different advantages and disadvantages.
The power that a fuel cell can create depends on a few factors. These include the fuel cell type, size, operating temperature and gas supply pressure. According to the US Department of Energy, one fuel cell produces around 0.5 to one volt of electricity. This is not enough to power even the smallest electrical devices. As we’ve previously mentioned, the fuel cells must work together in a stack in order to produce the required amount of electricity to run an appliance or vehicle.
Fuel cell power is determined in kilowatts. A kilowatt (kW) is 1,000 watts of electricity. Below, we’ve included some examples of appliances that can be found in your home and how much electricity they use:
The most popular fuel cell type is Polymer Electrolyte Membrane (PEM), which uses perfluoro sulfonic acid as its electrolyte. It is this fuel cell that is most commonly used in hydrogen vehicles and appliances for the home, such as a boiler. It can produce from 1 kW to 100 kW of electricity, depending on how many fuel cells are stacked together. It runs at a relatively low temperature, which makes it beneficial for use in the home. You could save around 40 per cent on your heating bills by switching to a fuel cell boiler along with a gas condensing boiler.
The type of fuel cell that is able to produce the most electricity is the Molten Carbonate fuel cell (MCFC). This cell uses high operating temperatures of around 650 °C and can create an electrical output of up to three megawatts (a megawatt is 1,000 kW or 100,000 watts). The high operating temperature makes them unsuitable for home use. Instead, this kind of fuel cell is most popular in natural gas and biogas power plants.