Green Energy: Fuel-Cell Technology

By Ronald R. Spadafora

Green energy includes the production of electricity with very little or no polluting by-products. Environmental impact and the dispersal of greenhouse (global warming) gases into the atmosphere are negligible. The country’s primary industrial source of air pollution is based on conventional electricity generation, whereby fossil fuels are burned. Green electrical power is generated from solar, wind, geothermal, and biogas. Unlike conventional technologies, fuel cells do not burn fossil fuels; rather, they are combined in a chemical process that converts hydrogen from fuel and oxygen in the air into direct current (DC) voltage. The fuel cell uses biogas as well as hydrogen and hydrocarbons to produce electricity and heat. In the past, fuel cells were large and extremely expensive to manufacture. With the support of federal government legislation as well as state initiatives, fuel-cell development is now moving to the forefront in clean energy technology. Some laws and initiatives introduced in the past 15 years are mentioned below.

  • The Emergency Economic Stabilization Act of 2008 included tax incentives to help minimize the cost of hydrogen and fuel-cell projects. It offered an investment tax credit of 30 percent for qualified fuel-cell property that was installed by the end of 2016. In addition, it features a credit of 10 percent for combined heat-and-power-systems. The American Recovery and Reinvestment Act of 2009 expanded fuel-cell installation incentives and the development of a hydrogen fueling infrastructure.
  • The United States Department of Energy supports the development of hydrogen and fuel-cell technologies through research to lower our country’s dependence on foreign oil and reduce the environmental impacts of fossil fuel combustion. The Hydrogen Fuel Initiative (HFI), a component of the Energy Policy Act of 2005, increased federal funding for hydrogen and fuel-cell research and development to $1.2 billion over five years. The goal was to enable hydrogen and fuel-cell technology to overcome obstacles facing the widespread use of hydrogen and fuel-cell technologies for transportation and stationary power generation.
  • In 2016, Governor Andrew M. Cuomo announced the New York State Public Service Commission’s approval of a 10-year, $5-billion Clean Energy Fund to accelerate the growth of New York’s clean energy economy. The Fund is administered by the New York State Energy Research and Development Authority (NYSERDA) and offers incentives for the purchase, installation, and operation of fuel-cell systems used for electricity production.

A fuel cell is an electrochemical device that is up to 50 percent efficient in converting fuel to electrical power, which is much more efficient than the combustion engine. Every fuel cell has two electrodes, one positive (anode) and one negative (cathode). The chemical reactions that produce electricity take place at the electrodes. Every fuel cell also has an electrolyte (acid, polymer, ceramic) that carries electrically charged particles from one electrode to the other and a catalyst (platinum) that speeds the chemical reactions at the electrodes.

(1) Dual 200-kilowatt fuel-cell units at the Red Hook water treatment plant. (Photos by author.)
(1) Dual 200-kilowatt fuel-cell units at the Red Hook water treatment plant. (Photos by author.)

A single fuel cell produces a small amount of voltage. Therefore, to increase power generation, many individual fuel cells are combined to create a fuel-cell stack. There are no moving parts in a fuel-cell stack, making it more reliable than a generator. This stack is integrated into a fuel-cell system with additional components, including a fuel reformer (separates hydrogen in alternate fuels), inverter [changes DC current to alternating current (AC)], power electronics, and controls.

Fuel cells, however, are different from batteries in that they require a continuous source of fuel and oxygen or air to sustain the chemical reaction. A battery stores electricity and needs regular recharging or replacement. Batteries are used to produce primary and backup electrical power as well as to heat cleanly and efficiently in commercial, industrial, and residential buildings. Fuel cells can be co-located with other energy resources (wind, solar, energy-storage batteries, and turbines) directly at a facility or as part of the grid system. They are also being installed as replacements for battery backup systems. The cells are installed close to the source that uses the power so that less energy is lost over transmission lines. They are also employed to power vehicles, machinery (forklifts), boats, and submarines.

Fuel and air (oxygen) flowing into a fuel cell, creating DC power. By-products of the reaction include water, heat, and carbon dioxide.
Fuel and air (oxygen) flowing into a fuel cell, creating DC power. By-products of the reaction include water, heat, and carbon dioxide.

Hydrogen Hazards

Hydrogen is an extremely flammable gas that is much lighter than air and has a wide explosive range. Explosive mixtures in air that can ignite spontaneously are created from as little as 4 percent hydrogen [lower explosive level (LEL)] to as much as 75 percent hydrogen (upper explosive limit). This characteristic is of utmost concern in an enclosed space. At the optimal range (29 percent hydrogen-to-air volume ratio), the energy required to initiate combustion is much lower than that required for other common fuels. Hydrogen vapors can be ignited by a pilot light, a cigarette, sparks, heaters, electrical equipment, and static discharge. Hydrogen produces a flame that is nearly invisible in the daylight. Additionally, heat from a hydrogen flame may be difficult to feel until firefighters get too close. It is colorless, odorless, tasteless, nontoxic, and noncorrosive.

(2) These sludge tanks are at a water treatment plant. Their contents are heated to approximately 100°F to produce biogas used in facility fuel cells.
(2) These sludge tanks are at a water treatment plant. Their contents are heated to approximately 100°F to produce biogas used in facility fuel cells.

The majority of hydrogen used to supply fuel-cell sites is stored in high-pressure cylinders. Very large systems may store hydrogen in liquid (cryogenic) form. The danger from the very low storage temperatures used for liquid hydrogen (approximately -418°F) include severe cold burns. Remove contaminated clothing immediately, and wash the underlying skin with soap and water.

Victims of hydrogen inhalation may experience symptoms that include headache, ringing in the ears, dizziness, drowsiness, unconsciousness, nausea, vomiting, and sensory depression. High concentrations can create an oxygen-deficient environment and pose the risk of death. Firefighters should check the oxygen content of the space before entering a hydrogen storage or fuel-cell area. First aid includes moving victims to fresh air and administering supplemental oxygen and artificial respiration, where required.

(3) Water treatment plant fuel-cell units commonly run on natural gas or biogas. Note the dual fuel lines leading into a reformer. The red piping is carrying biogas; the yellow pipe holds natural gas.
(3) Water treatment plant fuel-cell units commonly run on natural gas or biogas. Note the dual fuel lines leading into a reformer. The red piping is carrying biogas; the yellow pipe holds natural gas.

Alternate Fuels

Fuel cells operate most efficiently on pure hydrogen in pressurized gas or liquid form. Because of hydrogen’s potential risks, listed above, however, other fuels such as natural gas, liquefied petroleum gas, fuel oil, methanol, ethanol, biogas (digester gas), and gasoline can be reformed into a mixture containing hydrogen to serve as a reactant for the fuel cell. In addition, fuel cells have operated well on renewable biogas produced at wastewater treatment plants and landfill gas. Unfortunately, use of these fuels can lower the overall efficiency of the fuel cell by 25 percent and release small amounts of pollutants. Note: Biogas or digester gas has a composition of 70 percent methane and 30 percent carbon dioxide.

Biogas is being reformed to generate hydrogen for electrical power, heat, and vehicle fuel.
Biogas is being reformed to generate hydrogen for electrical power, heat, and vehicle fuel.

Firefighting Procedures at Fuel-Cell Installations (All Fuels)

Fixed gas and flame detectors are commonly installed in facilities that have fuel-cell installations. Listen and watch for audible/visual alarm signals. Escaping gas may ignite explosively. If leaking gas is not burning, eliminate the ignition sources, and monitor gas concentrations. Shut down power to the fuel-cell installation, and close the valves for the fuel supplying it. Ventilate the area, and use water spray to dissipate vapors. Except when human lives are in danger, let the fire burn until you can safely shut off the fuel supply. Use fog streams to cool adjacent areas and equipment. For cryogenic fuels, do not put water on pressure-relief valves because they will be inoperable if ice forms.

(4) This fixed-gas monitor with a red warning light is outside an enclosure harboring natural gas distribution piping for a fuel-cell installation.
(4) This fixed-gas monitor with a red warning light is outside an enclosure harboring natural gas distribution piping for a fuel-cell installation.

Self-contained breathing apparatus and personal protective clothing are essential. Additionally, firefighters should employ thermal imaging cameras and portable gas detectors to facilitate operations and enhance personal safety. Firefighters can carry multipurpose dry chemical, Class B, and Class C portable fire extinguishers.

Fire Protection Requirements for General Fuel-Cell Installations

Following are requirements from the fire protection perspective for fuel-cell installations in general:

  • The site must have an adequate fire hydrant water supply.
  • The site must have an automatic fire and combustible-gas alarm detection system.
  • An automatic fire suppression system must protect the indoor liquid-fuel pumps.
  • A combustible gas detector must be installed in the fuel-cell power system enclosure.
  • The combustible gas-detection system must be programmed to alarm at 25 percent of the LEL and interlocked to shut down the power system fuel supply at 60 percent of the LEL.
  • The automatic fire suppression system should be interconnected so it shuts off the fuel supply when activated.
  • A one-hour fire rated construction must separate the fuel-cell enclosure from the rest of the building.
  • All penetrations (electrical, plumbing) through the walls are to have a one-hour fire resistive rating.
  • The fire door rating must be equivalent to the rating of the barrier.
  • Piping, valves, and other fuel system components must be in an area not easily subject to physical damage from workers carrying tools and equipment, ceiling cranes, skates, and so on.
  • Fuel piping must be marked according to current labeling standards.
  • The Emergency Power Off (EPO) button that shuts off electrical power and the gas flow within the system must be nearby and accessible.
  • The electrical equipment associated with the fuel-cell installation should be designed according to the National Electrical Code [National Fire Protection Association (NFPA) 70].
  • Warning signs denoting the risk of electric shock should be posted.
  • The fuel-cell enclosure should have adequate high and low ventilation to alleviate the buildup of flammable gases.
  • The ventilation and exhaust system is to provide a negative or neutral pressure in the room containing the fuel-cell installation with respect to the building.
  • The fuel-cell room should not contain combustible materials, high-piled storage, or hazardous chemicals.
  • Access to the fuel-cell and fuel-storage area should be limited to competent personnel trained in this technology.
  • The fire department must approve the location that provides access to the area. Note: More specific requirements can be found in NFPA 853, Standard for the Installation of Stationary Fuel Cell Power Systems.

Emergency Planning Requirements/Recommendations

An emergency plan for a fuel-cell installation will address potential hazards, threats, and vulnerabilities that can harm building personnel and firefighters. It should be formulated with the assistance of local first responders, drawing on their experience in extinguishing/mitigating fires and emergencies.

(5) Correctly labeled natural gas piping for a fuel-cell installation.
(5) Correctly labeled natural gas piping for a fuel-cell installation.

Some examples of critical items that should be part of the plan include the following: a written fire/emergency plan that includes response to alarms and key personnel notifications and written information on fire prevention, fire extinguishment activities, and evacuation procedures; the posting of the fuel-cell equipment’s location, operating instructions, and emergency controls; the availability of portable flammable gas detectors at the service entrance to the fuel-cell installation; coordination with internal security personnel and incoming first responders; periodic drills on the fire/emergency plan; documented inspections; a written description of general housekeeping measures and of procedures that address impairments to fire protection systems; a list of the schedule for periodic inspection, testing, and maintenance of the fuel-cell system; standard markings on fuel piping and components; and first responder access through an approved location.

Fuel-Cell Installations in New York City (NYC)

In December 2016, a 750-kilowatt (kW) fuel-cell project using natural gas was completed at Morgan Stanley’s global headquarters in midtown Manhattan. It will provide approximately six million kW hours of clean electrical energy every year. Support for this project was provided by the NYSERDA through a long-term renewable energy credit contract. NYSERDA also funded the 400-kW fuel-cell project (natural gas) completed in 2011 at the 500-unit Octagon apartment complex on Roosevelt Island, the first residential building in New York State to be powered and heated by a fuel-cell system.

(6) The yellow Emergency Power Off button shuts off electrical power and gas flow within a fuel-cell system.
(6) The yellow Emergency Power Off button shuts off electrical power and gas flow within a fuel-cell system.

In 2001, the New York Power Authority (NYPA) installed a 200-kW fuel-cell system for the New York Aquarium in Coney Island, Brooklyn. Fueled by natural gas, the system was powered up during peak demand periods of the day to take some of the burden off the local utility company’s grid supply. Unfortunately, this system was damaged during Hurricane Sandy, in 2012, and has since been removed from the facility. The NYPA also installed a similar fuel-cell system at the Bronx Zoo in 2010. Notable fixed-cell sites in NYC fueled by biogas include the Hunt’s Point (Bronx), Red Hook (Brooklyn) (photo 1), and Oakwood Beach (Staten Island) water pollution/treatment plants.

Fuel cells are also used for first responder buildings. The Central Park, New York Police Department 22nd Precinct station house is completely off the grid. During 1999, a 200-kW fuel cell was installed. Power from its fuel cell allowed the facility to remain in operation during the August 2003 Northeast blackout while the rest of the city was in total darkness.

(7) A fuel-cell installation using natural gas on the setback roof of the Morgan Stanley building in midtown Manhattan.
(7) A fuel-cell installation using natural gas on the setback roof of the Morgan Stanley building in midtown Manhattan.

Stationary fuel-cell sites are being installed throughout the country. Fire companies should visit these locations to familiarize themselves with this growing technology.

Bibliography

Busby, Rebecca L. Hydrogen and Fuel Cells: A Comprehensive Guide. Tulsa: Okla.: PennWell Corporation, 2005.

National Fire Protection Association (NFPA), NFPA 2: Hydrogen Technologies Code, Quincy, Mass., 2016.

NFPA 853, Standard for the Installation of Stationary Fuel Cell Power Systems, 2015.

Shelley, Craig H., Anthony R. Cole, Timothy E. Markley. Industrial Firefighting for Municipal Firefighters. Tulsa, Okla.: PennWell Corporation, 2007.

Sorensen, Bent. Hydrogen and Fuel Cells-Emerging Technologies and Applications. Amsterdam, Netherlands: Elsevier (Academic Press), 2012.

United States Department of Energy (DOE). Hydrogen Fuel Initiative. https://www.hydrogen.energy.gov/h2_fuel_initiative.html.

RONALD R. SPADAFORA is an assistant chief and chief of fire prevention for the Fire Department of New York, where he has served since 1978.

(8) A fuel-cell system being installed into the basement of the Madagascar building at the Bronx Zoo.
(8) A fuel-cell system being installed into the basement of the Madagascar building at the Bronx Zoo.

Benefits of a Fixed Fuel-Cell Installation

Hydrogen Fire Operations Before Technology

In the days before modern technology, firefighters operating at hydrogen and alcohol-based fuel fires watched for thermal waves that can indicate the presence of heat and flame. They probed the suspected area slowly, advancing with corn-straw brooms. The broom was held forward at arm’s length and would ignite when it contacted the invisible flame. At the same time, firefighters would throw dirt ahead in anticipation of the combustible particles in the soil flaring up in the fire.

As a young firefighter, the first time I saw these techniques performed (by fellow firefighter Glenn Harris) was at an outdoor alcohol spill fire. I was dumbstruck. “What the heck is he doing?” I asked myself. Later, at the successful conclusion of the operation, he explained to me how he was using the broom and dirt the way miners use canaries. Both techniques have their drawbacks, however, since flame can change direction during windy weather conditions.

Green Building Challenges for the Fire Service
Sustainable Green Design and the Fire Service: The Saw-Tooth Roof
Green Building Construction and Daylighting: A Chief Officer’s Perspective

More Fire Engineering Issue Articles
Fire Engineering Archives

No posts to display