Expertise in Standby Power

An explanation of the circumstances in which fuel cells can be considered as a genuine alternative to generators!

So, what exactly are fuel cells?

Fuel cells can be regarded as power generators. A conventional generator uses an internal combustion engine to rotate an alternator and generate electricity. On the other hand, a fuel cell generates power by harvesting the component electrons and protons of the fuel (typically hydrogen or methanol), converting them to electrical power.

Hydrogen-powered PEM Fuel Cell

Because they have few moving parts, fuel cells have the potential to be very efficient and reliable. Moreover, fuel cells are comparatively quiet and, other than electricity and heat, they produce only water vapour. This makes them suitable for indoor use, meaning that the generated power can be close to, or inside the computer room.

In a direct comparison with diesel generators, the capital cost of fuel cells is higher but, as with every new technology, these costs are now falling. However, because of the absence of moving parts, fuel cells are considerably less expensive to maintain than generators.

Factors that weigh heavily in their favour are: reduced footprints, extended runtimes and lower life-time costs.

An alternative to generators

Fuel cells can be regarded as fulfilling the same function as a generator and you should consider them as an alternative approach for on-site power generation.

However, where fuel cells really come into their own is where installing a generator is, for one reason or another, not a viable option.

Imagine the scenario where your critical systems require backup power, probably for 4 hours or more, and you don’t have the space to house a generator. Your office may be on the 15th floor of a 20 floor block and the landlord will not allow a diesel generator on the roof; or you can’t obtain planning permission to install a generator because your office is in a city-centre location or adjacent to residential properties where the noise and emissions from a generator are unacceptable.

In these situations you should definitely be looking at fuel cell technology to support your IT systems during periods of mains power loss.

‘Clean’ energy

Another driver may be that your organisation accepts its Corporate and Social Responsibility (CSR) and has environmental policies that focus on improving air quality and reducing carbon-based emissions. The only by-products of operating a fuel cell are heat and clean water.

How is fuel cell technology developing?

Fuel cells have been around for a long time. The first fuel cell was demonstrated by William Grove in 1839. NASA did a lot of work on fuel cells in the 1960s, as they were the only practical means of power generation in space applications. But what has transformed the fuel cell situation has been the developments in materials science. Production of the fuel cell membrane is crucial, and this area has seen major developments in materials technology; the key has been the ability to produce high quality, consistent membrane, with an even flow on either side.

UPS Systems are the UK’s foremost authority on fuel cell standby power technology. We have been tracking fuel cells seriously for about six years. Two years ago, we decided that they were commercially viable and, in 2006, we installed a fuel cell standby power system at our HQ in the UK. The critical servers and desktop systems at our offices are now supported by a UPS linked to a 10kW hydrogen PEM fuel cell, providing potentially unlimited runtime in the event of power failure. We have subsequently installed such systems at customer locations in the UK.

Although fuel cells are now used extensively in vehicles and leisure applications – such as buses, caravans and yachts -it’s only recently that products have become suitable for standby power in static commercial applications.

Fuel cell technology has also advanced to the stage where it’s now being deployed in providing prime power, usually where mains power is not available, or as part of an organisation’s environmental policy to reduce greenhouse gas emissions.

What products are available now?

For standby power applications, the two most relevant technologies today are direct methanol (DMFC) and hydrogen-powered proton exchange membrane (PEM).

Today’s DMFC systems can generate up to 325W and are useful for providing standby power to communications and electronics sub-systems in remote locations. They are also particularly relevant for long runtime prime power (up to 12-months continuous running), where there are no connections to the grid; typical applications could be individual devices such as CCTV, signalling, signage or telemetry.

We are now installing hydrogen-powered PEM fuel cells in the range of from 5kW to 60kW. These can be configured for housing externally (as illustrated), or rack-mounted for installation in the computer room, and their rapid start-up makes them very suitable for standby power operations.

Advantages of hydrogen fuel cells, as opposed to diesel generators

• Standard hydrogen bottles offer a green alternative to conventional fuel and/or batteries
• Unlimited runtime – simply increase the number of hydrogen bottles
• Low audible noise – suitable for indoor installations
• Only heat and water by-products so safer for the environment
• In larger systems the waste heat from a fuel cell can be used to provide hot water or space heating
• Easy indoor installation- no major planning permission required
• Modular rack integrated design – easy to add more power
• Few moving parts, so less need for maintenance
• Politically reduces dependence on oil
• Some factories and plants may already have hydrogen installations or can utilise hydrogen produced by existing processes
• Certainly lighter than batteries and lighter than many conventional generators
• More energy efficient in power terms than either a battery or generator
• Generated power is close to, or inside, the computer room

Fuel cells for data centre prime power

Last summer, Fujitsu installed a 200-kilowatt fuel cell to provide half the energy necessary to cool its Sunnyvale campus data centre and labs. Fujitsu claims that it will have a payback “of about 3.5 years” and “a lifespan closer to 15 years.”

Fujitsu’s system provides combined heat and power to the facility. Firstly, a unit heats methane with steam to create hydrogen; this is then passed through a PEM fuel cell to generate power. Additionally, hot water from the methane-hydrogen reaction is cycled through the building’s central heating system.

Although not necessarily applicable to every industrial requirement, fuel cell prime power is well suited to the needs of data centres and manufacturing plants requiring 24-7 operation.

The IT Professionals Guide to Standby Power  – contents

• Part 1) Planning your standby power requirements
• Part 2) Potential Power Quality Problems
• Part 3) Sizing Generators
• Part 4) Fuel Cells
• Part 5) Specifying UPS
• Part 6) Matching a generator to your UPS
• Part 7) Making the right generator  choices
• Part 8 ) How to ensure your UPS batteries don’t fail
• Glossary

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