Deploying the fuel cell effectively reduces the footprint of the reserve battery banks, maintenance and replacement cost, without any major changes to existing system and at no additional start-up cost.
At remote sites, solar panels continue to be the main source of power, with batteries taking over at night. The fuel cell is only used in the event of an extended period of no sunshine, beyond the batteries' back-up capacity. Before the batteries are close to being completely discharged, an alarm signal is sent out, giving telecom operators ample time to dispatch a service team to the sites for hydrogen tank refilling or temporary battery charging via a portable generator.
Such remote monitoring means inconvenient trips to the off-grid telecom sites are made only when absolutely necessary.
Coping with an ever-growing telecom network becomes more challenging, especially in places where the electrical grid is unreliable. Operators looking to extend back-up power capability must increase energy storage capacity, pushing today's mainstream technologies beyond their limits.
Most back-up power systems used in telecom sites today rely on Valve Regulated Lead-Acid (VRLA) battery banks, which are costly to maintain and need replacements typically every 3 years. These battery banks are also typically heavy, bulky, and are prone to self-discharge.
Critical back-up time required at telecom sites ranges from 4 to 8 hours. Many telecom operators oversize their VRLA battery banks as much as 300% (up to 24 hours back-up time) to cater for unexpected long-duration outages. This solution is costly as all the battery banks need to be replaced at the end of their lifetime.
Remote off-grid telecom sites also integrate photovoltaic (PV) solar panels used to recharge the VRLA battery banks during the day. At night, the sites rely completely on these battery banks for power. Many telecom operators currently oversize their VRLA battery banks to cater for unexpected decreases in solar exposure, such as poor weather during several days. As a result, it is not uncommon for PV integrated off-grid telecom sites to have reserve battery banks that offer up to 3-5 days of run-time.
Stationary Back Up Power Solution
Telecom towers and base stations
Radio transmitter sites
Upper air observations programs
Remote back-up power systems
Distributed energy systems
Renewable energy storage