Fuel Cells: Environmental Impacts
Fuel cells are potentially a very clean, environmentally-friendly source of energy due to their super-efficient use of fuel for electricity and heat. However, reliance on fossil fuels should be reduced and hydrogen leakage concerns addressed for the technology to be as “green” as possible.
Environmental benefits
Fuel cells currently rely primarily on natural gas, a fossil fuel, to create the hydrogen need to produce electricity and heat. However, because this technology uses its fuel so efficiently, it is widely considered a clean energy technology. Current research into the use of solar, wind, and water power to create hydrogen may eventually make this technology completely renewable.
Even though fossil fuels are consumed in the electrochemical reaction inside of a fuel cell, fuel cells do not do not produce the same unhealthy air pollution emissions that are generated by burning gasoline in cars or burning coal and other fossil fuels in power plants. With fuel cells, there is no combustion, so fewer gases are released into the environment. For example, almost no sulfur oxides (SOx) or nitrogen oxides (NOx) are emitted, and emissions do not include any particulate matter. The greenhouse gas carbon dioxide (CO2) is an additional byproduct, but the high electrical efficiency of fuel cells provides much more electricity per unit of carbon released than conventional generators of similar size. Because these emissions are so low, certifications and permits are rarely needed to install commercial fuel cell systems.
Current research indicates that fuel cells could use hydrogen produced by electrolysis that is powered by electricity from renewable wind, solar, and water sources. If these solutions are implemented in the long run, the environmental benefits would be even greater. In that case, the only outputs of fuel cells would be electricity, heat, and water vapor (produced when the hydrogen and oxygen combine in the fuel cell).
Environmental drawbacks
While fuel cells have the potential to be a very clean source of energy if the hydrogen generation process uses renewable sources, current government-funded research requires the use of fossil fuels to produce the vast majority of hydrogen for fuel cells. Without a trend towards increased use of renewables for hydrogen production, the technology’s environmental benefits will continue to be somewhat offset by its reliance on fossil fuels.
There are also concerns that, in a large-scale hydrogen economy where hydrogen is used to power fuel cells and related technologies in a variety of applications, manufacturing, storing, and transporting hydrogen would result in leaks that could accumulate in the upper atmosphere, and potentially deplete polar ozone layers. Infrastructure designs that carefully eliminate the potential for leaks can minimize this risk.