With the increasing reliance on cloud-based software and storage, and the rise of AI use, the need for more data centres is critical for growth. The UK currently has approximately 500 data centres but, with continued growth, will struggle to handle capacity. 

In response, the government has included data centres in plans for critical national infrastructure. Major investment in new AI, data processing and cloud storage facilities will create the need to build more data centres. 

While the use of water to cool the servers is well-documented, the method of powering them is not so widely known. These giant warehouses full of servers need massive amounts of energy to function, and it has to be a stable source. 

To provide that energy, many data centres use solid oxide fuel cells which rely on toll-processed zirconates for their components. 

 

What are zirconates?

Zirconates are chemical compounds that do not naturally occur in nature. They are a product of chemical processing of zirconium oxide with either a carbonate or a metal oxide to produce a new compound. 

The chemical is produced by a method of heating to very high temperatures, usually through a toll or contract processing firm, as the facilities needed are very specialist.

Depending on the combination of chemical ingredients, it produces new compounds such as lead zirconate titanate, barium zirconate, calcium zirconate and lithium zirconate.

The resulting compounds are then shipped to manufacturers and plants where they have a myriad of uses. 

 

What are the industrial applications for zirconates?

Each type of zirconate has a specific set of characteristics that can be applied in industry. Common uses include surface coatings and ceramics used in electrical components.

Zirconium-based compounds can be employed for:

  • Catalysing reactions for creating polymers
  • Use in paints, sealants and certain inks, as a way to improve bonding
  • An eco-friendly surface coating to prevent corrosion on metals like steel and aluminium
  • An added thermal barrier when used as a lining for furnaces 
  • High-temperature electronics and energy transfer in the form of ceramics, sensors, and solid oxide fuel cells (SOFCs)

 

How do solid oxide fuel cells use zirconates?

The three main types of zirconates used in SOFCs are barium zirconate, zirconium hydroxide and calcium zirconate. 

 

Barium zirconate

Electroceramic components are used in fuel cells because of their conductivity; however, they are prone to deterioration with exposure to water and carbon dioxide. To counteract this effect while maintaining the conductivity, barium zirconate is added. 

The barium zirconate offers proton conductivity and thermal stability when used as a base material for fuel cells. Essentially, the compound acts as an electrolyte for the SOFC, allowing for transfer and storage of power. 

 

Zirconium hydroxide

Used in the manufacturing process for anodes as an alternative to carbon black, zirconium hydroxide creates pores in the material. 

Pore formers are essential to create the microstructure that allows gas to be absorbed and for ions to move through the material during charging and discharging. 

 

Calcium zirconate

Another variety of zirconates is calcium zirconate, which is used to enhance electrical conductivity. It is another form of electrolyte, or it can be added to the electrode material to provide more efficient proton conduction. 

 

What are the advantages of solid oxide fuel cells?

SOFCs provide a constant source of clean, on-site power which is not connected to the national grid. 

 

No wait for a grid connection

The advantage of being off-grid is that it is unaffected when there are fluctuations in supply or if the wait for a mains electricity connection is too long. 

 

Clean energy

The fuel cells avoid using combustion, which would produce harmful emissions; instead, the cell converts fuel directly into stored energy via an electrochemical process.

 

Economical

The reaction takes place at a very high temperature, of up to 1,000 degrees Celsius, which means that expensive catalysts such as platinum are unnecessary. The absence of the precious metals makes the fuel cells far more economical. 

 

Flexibility

Another advantage is the fuel type, which can be almost any type of hydrocarbon-based fuel. This includes natural gas, biogas, carbon monoxide, hydrogen, coal-derived gases and other hydrocarbons.

 

What are other uses for solid oxide fuel cells?

The high operating temperature makes SOFCs unsuitable for use in transport as people need to be thermally shielded from it. 

However, there are several other applications for SOFCs beyond powering the UK’s new data centres, where a reliable source of electricity is required.

  • Utility stations where interruptions to supply can be critical
  • Commercial buildings
  • Use in combined heat and power, where captured waste heat is used for heating buildings, hot water and manufacturing
  • Provision of back-up power in case of national grid failure
  • Reducing carbon footprint as a secondary purpose, where the power generated uses up waste products like gas from landfill