What are the characteristics of fuel cells?

1. Advantages

Fuel cells have attractive features of high efficiency, non-polluting, short construction period, easy maintenance and low cost.

(1) Energy conversion is efficient. The fuel cell directly converts the chemical energy of the fuel into electrical energy, which is not limited by the Carnot cycle. The current fuel-electrical energy conversion efficiency of the fuel cell system is 45%-60%; when combined with a steam turbine to form a combined power generation system, the total power generation efficiency can reach more than 70%; when combined with heat and power, the total energy conversion efficiency can reach more than 80%. The traditional large-scale thermal power generation efficiency is 35%-40%. In addition, thermal power generation must reach a certain scale to have high power generation efficiency, while the power generation efficiency of fuel cells has nothing to do with the size of the stack. Therefore, the fuel cell can be used as a central centralized power station or as a regionally distributed power station.

(2) Power generation is environmentally friendly. The thermal power generation emits pollutants such as dust, SO2, NOx, and hydrocarbons. There is no combustion process in the fuel cell power generation, no harmful substances are produced, and the pollutant emission is extremely low; when using pure hydrogen fuel, the reaction product is only water, which can achieve true “zero emissions”. In aerospace systems, the water produced by fuel cells is also available to astronauts. There are no rotating parts in the fuel cell stack, and the vibration noise is very low. The noise level of the high-power phosphoric acid fuel cell power generation system of 4.5MW and 11MV is lower than 55dB. Low-temperature fuel cells have the characteristics of low operating temperature, weak thermal radiation, low noise and quietness, and are more suitable for use in concealed military targets such as submarines.

(3) Good dynamic response and stable power supply. The fuel cell power generation system has a fast response speed to load changes. It can withstand the overload operation above the rated power or the low-load operation below the rated power, and the power generation efficiency fluctuates little and the power supply stability is high.

(4) Automatic operation. The fuel cell power generation system is fully automatic, with few mechanical moving parts, simple maintenance and low cost. It is suitable for use as a power source in remote areas, harsh environments and special occasions (such as space stations and space shuttles).

(5) Modular structure, convenient and durable. The fuel cell power station adopts a modular structure. Various modules are produced by the factory and integrated at the site of the power station. The power of the power station can be assembled by the battery stack according to the needs. The installation and construction are simple, the reliability is high, and the modules are easy to replace and maintain. The scale and installation location are flexible, the fuel cell power station occupies a small area, and the construction period is short, which is very convenient.

(6) Wide range of fuel sources. The selectivity of fuel is very high, including pure hydrogen, methanol, ethanol, natural gas, and even the most widely used gasoline, which can be used as fuel for fuel cells.

Fuel cells can use a variety of primary fuels, such as natural gas, coal gas, methanol, ethanol, gasoline, and low-quality fuels that are not suitable for power plants, such as lignite, waste wood, waste paper, and even municipal waste. Of course these fuels need to be reformed before they can be used.

2. Disadvantages

(1) The market price is expensive.

(2) Unsatisfactory life and stability at high temperature.

(3) Fuel cell technology is not popular enough.

(4) There is no perfect fuel supply system.