Right now, there are cars on the road capable of zero emissions–and, surprise, they do not use batteries. Instead, these miraculous vehicles run on fuel cells, which can be topped off at certain gas stations, run without emissions, function efficiently, and ultimately prove that the next step in the green energy movement may just be stuck in traffic the next lane over.

The Hyundai NEXO, a Fuel Cell Electric Vehicle. Credit: Hyundai

What is a fuel cell?

Fuel cells are devices that produce electricity without combustion. Instead, an electrochemical reaction provides continuous energy as long as fuel is available. Those fuels include hydrogen, methanol, or BioGas. Fuel cells vary considerably in size, and are frequently combined to create larger fuel cell systems that produce more power.

A picture of a fuel cell system. Credit: accelera

How do fuel cells work?

Fuel cells work similarly to a battery, but will never run out of energy–so long as fuel is still available. To understand fuel cells in more detail, consider the most common type–a hydrogen fuel cell. In this case, hydrogen is combined with oxygen to generate heat, electricity, and water. 

Diagram of a hydrogen fuel cell in a car. Credit: Firehouse

Where can fuel cells be used?

Fuel cells are versatile. Fuel cells are already being used in cars and trucks, with gas stations also offering hydrogen fuel for these cells. Fuel cells may also be incorporated into energy systems as emergency backup power, or to further power other processes to create more green energy stores. For example, fuel cells may help in the creation of emission-free green hydrogen, which can then be used to power other hydrogen-utilizing fuel cells. 

How is this considered part of the green energy future?

For all its benefits, renewable energy is not reliable–a windless day, some clouds, or low tides can hinder energy availability. Thus, renewable energy is only one piece of the green energy puzzle. To complete the puzzle, we need systems that make renewable energy more stable. 

Enter the fuel cell. Fuel cells act as a key backup to securing reliable electricity on the grid on days where there are slumps in renewable energy, such as on cloudy or windless days. 

Unlike other energy storage systems, fuel cell production is capable of zero emissions. Hydrogen powered fuel cells produce no emissions, and hydrogen itself can be produced via the chemical separation of hydrogen from water. If that process is powered with renewable energy sources, there are no greenhouse gas emissions.

The closest comparable technology–batteries–require the mining of critical limited materials such as lithium, nickel, and cobalt, which fuel cells do not. Overall, fuel cells remain a much more sustainable alternative to current energy storage technologies.

What are the downsides?

Fuel cells come with their own challenges, mostly coming down to the use of hydrogen and the costs. Most fuel cells to date use hydrogen, which has a tendency to corrode systems over time, reducing the longevity of the fuel cells. It is also challenging to transport due to hydrogen explosivity. 

Additionally, current proponents of fuel cells must factor in the high costs of production–namely, an average of $200,000 for a 120kW system. A further challenge of hydrogen is that as a fuel source, it remains more expensive than more common-place alternatives like natural gas.

What makes fuel cells particularly important?

Acidifying oceans, climate change, acid rain and cancer-causing emissions. These are the consequences of burning coal, oil, and gas, and it is not on track to change soon. 80% of American energy needs are met by fossil fuels. Yet there are renewable energy sources which can help generate safer energy that directly powers the things we need–our vehicles, homes, businesses, industries. 

These renewable energy sources may have been lacking in the past due to concerns about reliability, but with fuel cells, energy consistency is achievable without emissions nor the mining of critical limited materials. Fuel cells are just the thing the green energy movement needs to secure an energized future without the environmental consequences.