Stationary Fuel Cells

Stationary fuel cells are used for one of two general purposes. They either provide supplemental/emergency power for critical installations such as hospitals or they are used for onsite service in areas without access to the electrical grid.

Most stationary fuel systems are capable of power generation in the neighborhood of 200 kW. There are both smaller and larger systems, but 200 kW and 400 kW systems are useful for their modularity. They can be used separately or are combined into larger installations to provide additional electricity. Stationary systems producing as much power as 1 MW have been installed.

Most stationary systems consist of phosphoric acid fuel cells. There are two reasons that PAFCs are the most commonly used. The first is that they can run on almost any hydrocarbon fuel, particularly natural gas. Natural gas is easily supplied and because PAFCs are not at risk of carbon monoxide poisoning, they can utilize this fuel without processing it first.

The second reason that PAFCs are commonly used is due to their high operating temperatures. These fuel cells must run at all times, even if it is only at a low level of electricity generation. The reason for this is their high operating temperatures require long startup periods. Thus, the waste heat from the cells is generally used for hot water heating and space heating requirements even when electricity is not the primary motivation for running the fuel cell. The combined production of electricity and heat generation actually makes these fuel cells more efficient than separate electrical and heat generation solutions. Additionally, because they’re always on, they can provide uninterrupted power in critical applications.

Emergency Power Systems

Stationary fuel cells are found in a wide number of applications such as EPS Systems. Hospitals, laboratories, data centers, telecommunications equipment, and even modern naval ships use fuel cells as emergency backup. There are a number of advantages of using fuel cells over conventional generators, including reduced emissions, decreased noise and vibration, and the ability to run for long periods of time.

Uninterrupted Power Supply (UPS)

UPS systems are different from emergency power systems in that they provide immediate and uninterrupted power in the event that the grid ceases to deliver electricity. These types of systems are exceptionally useful for hospitals and other critical applications. Their only drawback is that they must always be running, even if at low levels, due to their long start-up times if they are not kept hot.

Cogeneration

Cogeneration is becoming increasingly popular in applications where fuel cells are used as standalone power supply systems. While the electrical generation capabilities of most stationary fuel cells are roughly 40 to 50% efficient, combining the waste heat produced by these systems with either hot water heating or space heating increases overall efficiency to around 80%.