Use of hydrogen fuel cells for data center backup power
Data centers run on electricity, and their backup generators typically run on fossil fuel. Hydrogen fuel cells could be a new form of sustainable energy, but it's costly.
Many data centers rely on backup generators that use fossil fuels, such as diesel or natural gas, to maintain uptime in case of a main power source failure. Fossil fuel-based generators are louder and more pollutive, which impacts human and environmental health. With these detrimental effects, data centers need a more sustainable alternative for backup power: hydrogen fuel cells.
Let's look at what a hydrogen fuel cell is, how it works, the advantages and disadvantages of the technology, and if it's just a trend or has long-term potential for data centers.
What is a hydrogen fuel cell?
A hydrogen fuel cell is an electrochemical device that combines hydrogen and oxygen to produce electricity. When hydrogen and oxygen mix within the fuel cell, a chemical reaction results in a charge of electricity that powers satellites, vehicles and backup generators. The chemical reaction also produces water and heat as by-products, which is a more sustainable and environmentally friendly product.
According to the Office of Energy Efficiency & Renewable Energy, there are several types of fuel cells. They are classified by the kind of electrochemical reactions that take place in the cell, the kind of catalysts it needs, the temperature range that the cell operates within and the necessary fuel.
For backup generators, polymer electrolyte membrane (PEM) fuel cells, also known as proton exchange membrane fuel cells, are often a power source. Phosphoric acid fuel cells can also support stationary power generation.
To provide power to a large data center backup generator, hydrogen fuel cells can stack together at the core of a fuel cell power system. The stacks can consist of dozens or even hundreds of fuel cells. The design of the fuel cell system depends on the type in use. Certain types, like PEMs, require special attention to factors like humidity as they do not function well when dry -- they might require a humidifier to operate.
Benefits of hydrogen fuel cells
Hydrogen fuel cell benefits include efficiency, quiet operation and environmental friendliness, as well as flexibility, reliability and scalability.
Hydrogen is an effective energy carrier. It can move, store and deliver energy easily.
Efficiency
Efficiency is especially appealing for data centers that need a reliable and powerful backup power source. A study by Equinix and the National University of Singapore's College of Design and Engineering compares PEM fuel cells to other types of alternative power supplies. PEM fuel cell efficiency was the highest. Fuel consumption -- per megawatt-hour -- for PEM fuel cells was also the lowest.
Quiet operation
Hydrogen fuel cells run quietly because chemical reactions happen within the cells themselves. They also have fewer components and moving parts. Other types of power generation can produce significant noise pollution, such as wind energy turbines and generators that run on fossil fuels. This makes hydrogen fuel cells an attractive option for data centers near or within populated communities.
Environmentally friendly
Hydrogen fuel cells can have low or even zero emissions. They do not produce carbon dioxide or other air pollutants. Hydrogen is a renewable resource because the atmosphere contains so much of it. However, there are some ways to produce hydrogen that are not sustainable, like the thermochemical method which takes hydrogen from fossil fuels.
Flexibility, reliability and scalability
Hydrogen is an effective energy carrier. It can move, store and deliver energy easily. Stationary fuel is a good option for backup power generation since hydrogen fuel cells only need hydrogen and oxygen to function. They can also scale up to power large applications.
Challenges to wide-scale hydrogen fuel cell adoption
Hydrogen fuel cell challenges include temperature sensitivity, cost, safety and hydrogen leakage.
Temperature sensitivity
Each type of fuel cell must have specific temperature ranges for optimal performance and to prevent degradation of parts. PEM fuel cells, which are most popular for backup power generators, can operate at low temperatures, at around 176 degrees Fahrenheit. This allows the fuel cells to start quickly with less warm-up time. The same temperature must be consistent throughout the cell.
Other types of fuel cells require very high temperatures to work, which results in more wear and tear on the battery components.
Cost
Hydrogen fuel cells are more expensive than most other types of energy generation. Depending on the type of fuel cell, certain precious materials might be necessary for the fuel cell to function, which can drive up the production cost.
There's also a lack of widespread infrastructure for hydrogen. To decrease the cost of hydrogen fuel, infrastructure must advance for the fuel to be adopted on a mass-market level.
Safety
According to the Center for Hydrogen Safety, one of the primary concerns about hydrogen is its wide flammability range. Hydrogen also takes very little energy to ignite. These two factors make for a potentially dangerous environment that might inhibit widespread adoption of the fuel.
Hydrogen leakage
According to a study by the Center for International Climate Research, a fraction of hydrogen leaks into the atmosphere when it undergoes transport, storage and use. The study posits that the global warming effect of hydrogen leaks is almost 12 times stronger than carbon dioxide despite hydrogen's lack of direct radiative properties. Given this, it is critical that the hydrogen industry finds a way to better contain hydrogen and limit these leakages for a hydrogen economy to be viable.
The future of sustainable energy?
Time will tell if hydrogen fuel cells are the next sustainable fuel choice. Right now, more research is necessary to ensure that hydrogen is as environmentally friendly as it appears.
Some organizations are experimenting with hydrogen fuel cells to test their viability. For example, Microsoft and Plug, a leading hydrogen fuel cell manufacturer, are looking to create a fuel cell system that could deliver three megawatts of power -- enough to power 10,000 servers.
Plug also works with other global organization data centers, such as Amazon and BMW, and they expect hydrogen fuel cell demand to pick up in the second half of 2025. The U.S. Department of Energy is also set to fund and invest in hydrogen fuel to combat climate change.
If hydrogen fuel cells become more technically secure, affordable and available on a mass-market level, they might be a viable option that can help protect the environment better than diesel or natural gas. For now, data center administrators who want to adopt more sustainable technology should keep an eye on how the market progresses before purchasing hydrogen fuel cells.
Jacob Roundy is a freelance writer and editor, specializing in a variety of technology topics, including data centers and sustainability.
