In this first part of EEWorld’s “virtual roundtable” discussion on fuel cells, our panelists delve into the impact of fuel cells’ emergence compared with conventional rechargeable batteries: What performance advantage do fuel cells have? What is the barrier to large scale deployment? How can fuel cell performance be improved? And how do the environmental or safety hazards of fuel cells compare with conventional rechargeable batteries? Joining us for this virtual roundtable are Rami Reshef (RR), CEO and founder of GenCell Energy, and Andy Marsh (AM), CEO of Plug Power.
JS: What is the biggest performance advantage that fuel cells have versus conventional rechargeable batteries?
RR: From our perspective, we do not see fuel cells as substitutes for rechargeable batteries but as complementary. In terms of performance, rechargeable batteries have a defined and limited amount of power. With each charge cycle, they are weakened until finally they must be disposed of and replaced. Rechargeable batteries are sensitive to temperature and humidity. The charging time is long and increases over the battery’s lifetime. Moreover, the greater the power requirement, the larger and heavier the battery will be.
The biggest performance advantages of fuel cells are their reliability and long lifetime; with few moving parts and a closed-loop electrochemical reaction, the fuel cell is a durable workhorse that can withstand extreme weather conditions. For as long as fuel is available, the fuel cell will continue to produce energy through its proven electrochemical generation process.
By leveraging the complementary advantages of fuel cells and batteries together, you can achieve the best of both worlds. The key advantage of batteries is their immediate kick-in with full power to provide a rapid boost that can power acceleration and heavy power injection. But after these first few seconds of power output when there is momentum, the actual power requirement for most loads falls significantly. Here the performance advantage of fuel cells to provide a continuous, steady, smooth, and resilient long-duration power for extended duration – ostensibly for as long as fuel can be supplied – comes into play.
For most power applications, using a combination of batteries and fuel cells will give the best performance – use a small battery to supply the initial power boost and then use the fuel cell to provide long-term power to support the continuous load, including the routine recharging of the battery.
AM: Power Density and Range: fuel cell energy density is four times more than batteries, and a tank of hydrogen contains more than double the energy of a battery at the same weight. Fuel cells allow easy scalability for users to increase range without the elimination of cargo space. This is important in middle-mile and long-haul green mobility markets. In these applications, you must double the batteries on board to double the range of a battery-electric vehicle. With fuel cells, to double the range, you only have to add more hydrogen. That supports a 50-60% increase in payload versus battery electric vehicles.
Fast Fueling/Simple Infrastructure: Batteries can take hours, even an entire night, to recharge. In comparison, fuel cell-powered vehicles see ten times faster fueling, and you get extended range at maximum power. Additionally, once you exceed ten vehicles in your fleet, fueling infrastructure becomes more cost-competitive than putting in extensive battery charging stations to keep up with demand.
JS: What is the largest barrier to more broad-based use of fuel cells?
AM: In order for adoption to ramp up, we need more hydrogen stations, ideally providing green hydrogen to power the increased demand we’ve seen for HFCs. Plug Power has already taken steps in green hydrogen with the acquisitions of United Hydrogen and Giner ELX, which will allow the company to build out green hydrogen generation plants and provide customers and more with widespread access to this renewable fuel. These acquisitions further enhance Plug Power’s position in the hydrogen industry with capabilities in generation, liquefaction, and distribution of hydrogen fuel complementing its industry-leading position in the design, construction, and operation of customer-facing hydrogen fueling stations.
RR: For different types of fuel cells, there are different barriers; the most common fuel cells known as PEM – Proton Exchange Membrane fuel cells require noble metal components and run at extremely high temperatures, and their membranes are very sensitive, requiring specific conditions and servicing to keep them moist and requiring high purity fuels which require filtration. All of these factors add to the expense, which make the Capex investment a barrier of entry for these fuel cells.
Alkaline fuel cells run at lower temperatures and higher efficiencies than PEM fuel cells. Thanks to some patented technological innovations, GenCell has succeeded in developing fuel cells that are platinum-free and that can run on industrial-grade hydrogen; both of these innovations have significantly reduced the costs of these types of fuel cells.
Nevertheless, by far, the greatest barrier to wide adoption of fuel cells is the availability of fuel, which is, in most cases, hydrogen. Hydrogen is ubiquitous in our atmosphere, but the fact that at room temperature, it takes the form of a very low-density gas, it is extremely complicated and expensive to transport and store, whether through cryogenically liquifying the hydrogen or shipping and piping the gas – either way incurs significant expense to make the hydrogen available where the power is needed.
GenCell proposes another innovative approach to overcome this barrier – ammonia (NH3). Because ammonia has high hydrogen density and is far more easily and safely transported and stored as a liquid, GenCell has developed a solution that supplies the fuel cell together with a store of liquid ammonia from which we extract hydrogen on-demand in the location where the power is needed. We are confident that this solution bridges this key barrier and can enable broad and rapid uptake of alkaline fuel cells for many applications.
JS: What factors impact the ramp-up rate for fuel cells, and what can be done to enable faster ramp-ups?
RR: Fuel cells were initially invented in the 19th century and have been around for many years, but their ramp-up rate has been low because of the high costs and complex applications that were traditionally associated with fuel cells that prevented their more rapid uptake.
Another factor that negatively impacted the fuel cell ramp-up rate has been the negative view that the public generally has of hydrogen as being dangerous and having serious safety hazards, a view that was strongly determined by the use of hydrogen bombs in World War II and the Hindenburg hydrogen airship disaster. These highly publicized incidents have negatively colored the public’s view of hydrogen fuel cells. In reality, when handled properly, hydrogen does not have significant safety hazards and is not any more flammable or explosive than fossil fuels used for other power applications.
Education of the market regarding the safety of hydrogen and the availability of affordable, efficient alkaline fuel cells that can provide reliable and cost-effective substitutes for pollutant fossil fuel sources will enable faster ramp-up for fuel cells, especially today when the public is aware of the need to more rapidly accelerate the transition away from fossil fuel power sources to cleaner alternatives to prevent further global warming that exacerbates climate change.
JS: What environmental or safety hazards are associated with various fuel cell technologies, and how do they compare with rechargeable batteries?
AM: Fuel cells produce zero emissions, are quiet and efficient, and can work in environments as low as -20 degrees F. Much like many gases we use every day, hydrogen is flammable, but as long as it is handled properly, it poses no danger. Plug Power has spent decades developing its products and creating strict safety standards around the distribution of hydrogen. When installing hydrogen fueling systems for its clients, Plug Power provides instructions on how to safely refuel the fuel cells for all those who will be using the equipment.
Alternatively, batteries contain lead and highly corrosive sulfuric acid and require ventilation and personal protective equipment for employees’ safety. Contact with sulfuric acid can lead to permanent bodily damage and even death. As these types of power do degrade over time, the real hazard comes when discarding the batteries. If improperly discarded, the batteries can leak and contaminate soil and groundwater, causing devastating environmental trauma as well as potentially poisoning resources used by humans daily.
RR: As mentioned earlier, alkaline fuel cells offer benefits in terms of environmental impact and do not have significant safety hazards associated with their operation. Popular opinion questioning the safety of hydrogen as a fuel is a topic that the industry is seeking to impact through wide market education to make consumers familiar with the facts regarding hydrogen safety. Flammable like all fuels, hydrogen is safer than gasoline because having low density and being lighter than air, it dissipates and rises quickly when released into the atmosphere. Hydrogen has been produced, stored, and delivered safely in the United States for more than 50 years, so overcoming the stigma is not simple but should not be impossible. In comparison, the lead-acid and lithium-ion used in batteries are prone to catching fire or exploding if short-circuited or overcharged; recent accounts of aircraft, electric vehicles, and even mobile phone fires caused by overcharging or accidental damage to lithium-Ion batteries attest to their flammability.
Another key environmental hazard is the disposal of toxic materials such as Lithium-Ion, making the disposal of rechargeable batteries problematic and expensive. GenCell’s alkaline fuel cells use a liquid electrolyte, Potassium Hydroxide (KOH), the liquid solution in which the electrodes are suspended in the fuel cell. GenCell monitors the safe disposal of the Potassium Hydroxide (KOH) electrolyte. Throughout the production process, GenCell tests the electrolyte for reuse and consumption. After continuous reuse, when the solution cannot be further reused, it is safely disposed of in compliance with strict standards for disposal of Hazardous Materials.
Another key concern with the common rechargeable battery technologies is their limited recharging cycles and lifetime. Lead-acid batteries lose their effectivity when deeply discharged or left for long periods in a discharged state. Lithium-ion batteries require tightly-controlled charging and discharging and, with repeated deep-cycling or when stored in a fully charged state, will decompose and lose their power capacity. For this reason, the batteries need to be disposed of replaced more frequently, which creates a serious environmental concern. In comparison, GenCell’s fuel cells have lifetimes of 15 years or more, making them far more eco-friendly.