OPERATION OF FUEL CELL POWER PLANTS:
Telecommunications installations with backup fuel cell power often incorporate fuel cells and batteries. As the system voltage changes, rectifiers or controllers switch between the primary power source and the backup power sources.In the absence of grid power or another primary alternating current (AC) power source, the fuel cells, or a combination of fuel cells and batteries, provide direct current (DC) power to run the equipment. The fuel cells have internal batteries that provide temporary “bridge” power until the fuel cell reaches peak power production and takes over the load. When the primary power source is restored, the fuel cells shut down, and the load is returned to the primary source.
When the hydrogen fuel supply in a fuel cell is low, a self-checking alarm remotely alerts the operator to replenish the storage containers. The operator can resupply the fuel cell via “hot swapping” or “bumping.” In a “hot-swap” resupply, operators deliver pre filled hydrogen storage containers to the site and swap them individually with the depleted containers without disrupting backup operations. “Bump” resupply involves refilling the storage containers at the site. A hydrogen tanker delivers hydrogen gas and replenishes the existing storage supply.
MAINTENANCE REQUIREMENT FOR FUEL CELL POWER PLANTS:
Fuel cells used for telecommunications backup power require less maintenance than batteries or generators, but they do require periodic maintenance. Some vendors maintain fuel cell backup power systems annually. The fuel cell power plant performs self-maintenance, and operators can configure the units to run unattended conditioning cycles to ensure operability. The operator determines the frequency of self-tests, but manufacturers recommend one-month cycles. |
| Figure 2. Schematic of a PEM Fuel Cell |