Solid Oxide Fuel Cells (SOFC)
Fuel cells have been around for over a century and though there are many types, the most commonly known is the Polymer Electrolyte Membrane Fuel Cell or PEM for short. Fuel cells generate electricity through an electrochemical process which is achieved through the conversion of the chemical energy of fuels like hydrogen.
Lets use PEM fuel cells as an example. Simply put this process is done by having an electrolyte in the centre of the fuel cell. Then on either side you have electrodes with the negative anode on the left and the positive cathode on the right. These are connected by a wire at the top of the fuel cell. This wire transports electrodes from left to right.
In electrolysis these two are the opposite with the cathode being negative and the anode being positive. The process uses electricity to split water into hydrogen and oxygen.
These electrodes are made up of porous carbon along with catalysts to help enhance the process. Surrounding these electrodes are sections where the inlet of fuels enter. Hydrogen is pushed into the left hand side of the fuel cell and oxygen into the right. As the hydrogen enters the compartment and reacts with the anode it becomes oxidised and loses atoms. In doing so it creates a difference in charge across the cells. This drives electrons around the circuit creating electricity. The process produces excess water and heat which is ejected through an outlet.
Hydrogen 101
Hydrogen exists naturally in nature. You would most commonly see it in the molecule for water; H2O. The H2 represents two hydrogen atoms. It is the most abundant element on earth and can be found most commonly bound up with other substances such as water or methane. There are many ways to create hydrogen, also known as the hydrogen rainbow.
The main use of fuels cells such as these can be seen in the replacement of combustion engines and batteries in the car manufacturing industry. The use of fuel cells is also being seen in the power generation sector such as within Combined Heath & Power (CHP) and it is this market that Solid Oxide Fuel Cells (SOFC) are gaining traction over PEMFC. The difference with SOFC is the electrolyte is a solid oxide material hence the name, specifically an ion-conducting oxide ceramic. Alongside this, the anodes are also made up of differing material to that of their counterpart PEMFC. Compared to other fuel cells they produce fewer electrolyte management issues, better efficiency and work best where continuous power output is required, hence their growing demand in the power generation market.
Two reports were released last year that demonstrated the growing potential of these fuel cells. The first was by Frost & Sullivan titled ‘stationary fuel cell growth’1. The report found that the leading market for stationary fuel cells were the USA, South Korea and Japan. According to Frost & Sullivan this market has around 50 actors and in the installed capacity market the top 4 actors have an 85% market share. The report further details that data centres are the key to future fuel cell market growth.
The second report from IDTechEx titled ‘solid oxide fuel cells 2023 – 2033: technology, applications and market forecasts’2 predicts that by 2033 the SOFC market, in both mobility and stationary, will reach a market value of US$6.8bn. The report found a large percentage of the market share for 2023 was made up of power grids, data and commercial. In the US Walmart uses SOFC provided by one of the big four, Bloom Energy, to ensure their supermarkets can run 24/7.
Because of the developing growth, key actors are entering and re-entering the SOFC market. The most notable is Ballard who were the first in the market after entering in 2015 through acquiring Protonex. With Haldor entering in 2021 and GE Power returning the same year.
Transitioning from fossil fuels is a key part of both countries and businesses strategies for a greener cleaner energy future. Fuel cells provide a level of reliability and run time that combustion engineers can not. Coupling this with their ability to cut carbon emissions means fuel cell technology will only become more prominent in the energy management landscape in the near future. One day you could be driving a fuel cell based car.
1 Frost
2 IDTechex
