Both wireline and wireless companies know the dilemma of ensuring network availability in a rapidly expanding network. It comes as no surprise, then, that service providers are exploring alternative technologies. Their job is to find solutions with durability, flexibility and reliability--at a reasonable cost.

Where tradition cannot go

In the comfortable confines of the central switching office, traditional technologies have long provided highly reliable power. Valve-regulated lead-acid (VRLA) batteries typically achieve useful life spans of 20 years. Maintenance techniques for these and other widely used sources, such as engine-generator sets, are proven and easily implemented. Onsite personnel can monitor loads, equipment condition and provisioning requirements. Even setting aside the footprint and installation/replacement challenges, there is limited rationale for deploying new power technology in such a critical environment.

The outdoors is a different story. VRLA batteries, sensitive to temperature, are proving short-lived, too heavy for many outdoor applications, and laden with environmental issues. Engine-generator sets produce combustion emissions and noise. With nearly half a million wireline and wireless sites scattered across the U.S., preventative maintenance can get cost-prohibitive very quickly. Over the last few years, researchers have made some advances in adapting the traditional technologies to the OSP environment. New, more promising battery types have also cropped up. Still, these advances may well end up sharing the new distributed landscape with yet another alternative.

Fuel cells in the field

Stationary fuel cells circumvent battery technology altogether. In the proton-exchange membrane (PEM) version, fuel atoms--hydrogen--are divided into protons and electrons. The electrons travel around the membrane, generating DC power; the protons pass through, combining with oxygen to produce heat and water.

The beauty of fuel cells is that they are particularly adaptable to the OSP environment. PEM fuel cells, moreover, have addressed many of the limitations of battery technology. Initial unit cost runs roughly half to one-third that of lithium-ion batteries, one of the new battery technologies for backup power. While still more expensive than VRLA batteries, fuel cells carry a lower life-cycle cost, thanks to lower maintenance needs and longer life.

In addition, fuel cells are already in the marketplace--and gaining traction. A range of government agencies, from the Department of Defense to the National Institute for Standards and Technology, have provided extensive support for commercialization. Providers across the telephony spectrum are paying attention as well. Last July, Verizon completed an extensive field trial of two GenCore systems from Plug Power at the international airport in Albany, New York. Across the Atlantic, Orange installed a GenCore unit to provide backup power for a remote cell phone tower, 1500 feet above sea level in Elgin, Scotland.

Challenges remain, of course. Chief among them is the logistics of fuel supply: for example, refilling of tanks via drop-off fueling and the corresponding concerns surrounding the siting of hydrogen. Fuel cell companies are collaborating with telecom operators to grapple with these issues.

What's next?

Both fuel cells and their battery counterparts will continue to see further development, driving down costs while expanding features. Because the needs are so varied, many of these technologies are likely to take their place in a mosaic of backup power solutions.

Even now, however, telecoms can find affordable alternatives for OSP backup power. Fuel cells in particular offer hope for everyone’s favorite win-win: reliable service and lower costs.

Eoin Connolly is the Director of Product Marketing for Plug Power Inc.

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