Page 37 - Energize December 2022

TECHNICAL

Fuel cell power for critical data sites

Fuel cells are finding increasing use both as back-up power and as primary power sources for

critical sites and are proving to be an effective alternative to traditional diesel generators and
battery backup systems. The technology features both quick start up and long run time, without
emissions or noise, at a cost and reliability that are competitive with existing solutions.

by Mike Rycroft, Energize

uel cells (FC) can be used to support critical loads for energy natural gas to liquid hydrocarbon fuels, while future versions are
reliability, security, sustainability and economic benefit. They likely to be based purely on hydrogen gas. FC using LNG and liquid
Foffer potential for backup or prime power and combined heat fuels require an additional reformer stage to extract the hydrogen
and power applications in the data centre. necessary.

Two major research projects are underway to establish standards Data centres have become critically important for a wide range
for the use of FC in data centres: of data services. Currently they account for 3,5% of the total
• The European EcoEdge PrimePower (E2P2) project is a proof- electricity demand worldwide, and that share is projected to
of-concept initiative aiming to develop and demonstrate increase exponentially as more industries and users turn to digital
low environmental impact fuel cells that provide economic platforms to carry out routine daily activities. Given the projected
and resilient prime power solutions for the data centre demand increase for data-based services and the associated
environment power consumption, data centre managers are considering FCs
• The NREL Hydrogen and Fuel Cells for Data Applications. This to be more cost-effective, sustainable, and reliable ways to power
project aims to evaluate the application and suitability of their operations. Fuel cells can be an option to help meet those
hydrogen fuel cells for primary/backup power for data centres needs and to serve as an option with a range of potential benefits.
There are several options available for FC use:
Whereas FC in the past have been used as backup power source, • Backup power: This would use either a large, centralised fuel
large high-capacity FC are finding an application as primary power cell or distributed fuel cells used as backup and sized to meet
in data centres and server farms. The availability of MW sized FC the critical loads of the centre.
units has made this possible. These high-capacity FCs are of the • Prime power: A larger capacity fuel cell situated adjacent to
solid oxide (SOFC) or molten carbonate (MCFC) types. Commercial and outside of the data centre sized to meet the critical loads
units range in size from tens of kW to MW. FC are now being with optional thermal usage.
considered as the primary power source for server farms data • Distributed prime power: This involves smaller fuel cells
centres and cloud complexes. The availability of green hydrogen installed at rack level inside the data centre with the option of
will no doubt make this a more viable system thermal usage.
Technologies that are used to provide secure power in data
centres are primarily diesel generators (for backup power) and Currently, FC in the data industry mainly use natural gas. Future
electricity from the grid (for prime power). Incorporating fuel cells fuel options could include on-site hydrogen storage, intermediary
in a data centre would have to meet or exceed the performance fuels, or hydrogen infrastructure by pipeline, delivery, or on-site
and value offered by these technologies. Key challenges are production. Natural gas is seen as a potential bridge to green
a reliable fuel supply and storage, especially in prime power hydrogen, which would allow renewable hydrogen systems to
applications. Benefits over diesel generators, however, include scale up.
reduced air and noise pollution as well as increased efficiency.
FC are an essential component of the looming hydrogen Back-up power application
economy. The inclusion of “green hydrogen” in the future energy Traditionally, backup power has been provided by diesel generator
mix has spurred the development of hydrogen-based fuel cells, sets followed by downstream battery-based UPS systems closer to
and considerable advances in fuel cell technology have taken the equipment. The first step in incorporating a FC would be as a
place over the last few years, with increases in efficiency, size and source of full or partial backup power for the grid supply where it
operational controls being the most significant, not to mention the would supply power in the event of a mains failure.
wide variety of FC available on the market. Using a FC instead of a diesel generator would be the least
Initially, FCs were used at remote telecommunication sites disruptive, but replacement solutions would have to meet the
and IT centres, but their use has spread to other critical sites as energy requirements with similar operating characteristics to
well. Current FC installations make use of a variety of fuels, from diesel generators.

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