Hydrogen Fuel Cells: Unlimited UPS (Sep-04)

From Lauraibm

MI Summary

Full story: Hydrogen Fuel Cells: Unlimited UPS (Sep-04)

An Uninterruptible Power Supply (UPS) allows computer systems to keep running for a short time even if a facility loses power—the advantage being that the user has time to save data before the power cuts out. In the past UPS systems have relied on battery or diesel generators. However, recent advances in hydrogen fuel cell technology have provided a more environmentally friendly solution. The advantage of using hydrogen is that there is no CO₂ emitted.

Like a battery, the fuel cell produces DC voltage, which is the same as used by UPS systems. Automatically, it's a good match. Another benefit is that hydrogen cells are a 10-year product. A battery for a UPS only lasts three or four years. Over those 10 years, facility executives will have to replace traditional batteries three times.

The disadvantage of hydrogen is that it is not very cost-competitive for short runs when compared to other UPS options, thus the future of hydrogen becoming a major player in the economy will depend upon producing, supplying and storing the element at a low cost for end users.

Text of Article

A new fuel source has boundless limitations for running UPS systems.

By Matt Stansberry

Last year, after power outages shut down parts of the East Coast, the Midwest, and Canada, facility executives turned their attention towards uninterruptible power supply (UPS). UPS allows computer systems to keep running for a short time if a facility loses power. So if you are using the computer when the UPS notifies you of the power loss, you have time to save your data before the secondary power source runs out.

Typically, these UPS systems have relied on batteries or diesel generators for backup power. But advances in hydrogen fuel cell technology have provided an environmentally friendly solution able to support unlimited back up time as long as hydrogen fuel is supplied.

Hydrogen fuel cells produce electricity through a chemical reaction between hydrogen and oxygen. It's probably the most fundamental chemical reaction that can exist between two elements. In the most basic terms, hydrogen and oxygen–at low temperatures–react over a catalyst to create electricity and water.

The hydrogen is contained in replaceable cylinders and is piped directly to the fuel cell module. These standard welding cylinders are 5'6" tall and 9" in diameter. The hydrogen from these tanks is pumped into a fuel cell, and oxygen from the air is pumped in from the other side. A catalyst inside the fuel cell splits the hydrogen molecules into protons and electrons. The electrons pass through a circuit, producing energy. The protons pass through a membrane where they form H2O with the oxygen.

Like a battery, the fuel cell produces DC voltage, which is the same voltage used by UPS systems. Automatically, it's a good match.

The trick is to adjust the voltage level on the fuel cells to the voltage level on the UPS. Rackmount systems are scalable, so companies can use low power applications (one or two kilowatt) or pull up to 30 kilowatts to meet a user's needs by adding more modules.

Hydrogen fuel cell units are approximately the same size as comparable diesel generator sets but are much lighter. They are also much lighter than batteries. For example, a one kilowatt hydrogen fuel cell UPS that gets three hours of run time can replace about 1,200 pounds of batteries. And it only weighs 150 pounds. Where you have indoor weight limitations–such as raised access floors in server rooms–the fuel cells provide an attractive option.

Hydrogen fuel cells are making inroads in applications where facility executives can't use conventional means of generating power because of noise or pollution. For example, you can't use a diesel generator or store diesel fuel indoors. Hydrogen doesn't emit any noxious fumes. There's no CO2. It also runs very quietly. You could have one under your desk and not even know it. The main by-product of the system is about one liter of ultra pure water per hour, which can be easily drained under an access floor of the server room.

One of the hindering factors is that fuel cells are not very cost competitive for short run times when compared to other UPS options. Unfortunately, typical UPS needs are often shorter run operations. The value of hydrogen makes sense for facility executives considering extended run applications. At eight hour run times, fuel cells can make much more economic sense.

Another benefit is that hydrogen cells are a 10 year product. A battery for a UPS only lasts three or four years. Over those 10 years, facility executives will have to replace traditional batteries three times.

One market that may be strongly considering hydrogen power is emergency services. Regulations are in place that will require 911 call centers to have backup power for a minimum of eight hours. During last year's blackouts, many emergency systems did not have the capability for eight hours of backup power.

Another consideration when using fuel cells is that the hydrogen needs to be stored according to certain codes. Facility executives have to use caution when handling these tanks, just as they would with any other fuel.

The technology will continue to become more reliable, more compact, and less expensive. In the future, fuel cells will probably see higher power densities. Eventually, promoters of the technology hope to run vehicles on hydrogen fuel cells to help relieve U.S. dependence on fossil fuel. Whether or not hydrogen becomes a major player in the economy will depend on producing, supplying, and storing the element at a low cost for end users.

• Source: Today's Facility Manager