Fully Charged: Examining the Pros and Cons of Using Fuel Cell Systems in Large-Scale Applications
02.9.2015
Bernie Woytek in Chicago, Mission Critical, data centers, mission critical

Image © Vincenzo Centinaro

The United States is one of the world’s largest and fastest growing markets for fuel cell technology. In 2012, nearly 80 percent of total investment in the global fuel cell industry was made in U.S. companies.

As with all other major components of the design and engineering process, the implications of a fuel cell system as a power supply must be evaluated closely to determine if a fuel cell system is a viable and beneficial power supply system for the project. The utilization of fuel cells as a power source, like all other power supplies, has many benefits as well as disadvantages.

Benefits of Fuel Cells on Critical Facilities

Reliability

One very important advantage of fuel cell technology is the very high reliability of the on-site power generation they provide. Fuel cells enable the buildings they use to go off grid. In the past 5 years, storms like Hurricane Irene in 2011 and Super Storm Sandy in 2013, as well as large scale rolling blackouts in Southern California, have caused extensive loss and damages. In all of these incidents, telecommunications facilities, grocery stores, data centers, healthcare facilities, and other businesses that had operating fuel cell systems in place were some or the only facilities up and operational--both during and directly following catastrophic events--for hours or days at a time.

Fuel cell systems basically have no moving parts that may break down over time. Even the ancillary systems of fans, pumps, and controls in a complete fuel cell system are simple, proven technologies that are shown to be extremely reliable. Studies and real life examples have shown that fuel cell systems operate at 99.9999% availability, which is up to 10 times more reliable than power from the grid and back-up generators with UPS systems. Even countries in the Middle East (where fossil fuels are in abundance) are investigating and implementing fuel cell systems to provide greater reliability for buildings and other facilities through the use of distributed generation. This increased system reliability enables the buildings and facilities to reduce or even eliminate other back-up power systems that can be detrimental or hazardous to the site. Back-up generators can be eliminated, reducing carbon emissions, noise levels, and fuel storage on site. Battery rooms and other costly UPS systems can be eliminated as well. In some applications, dangerous medium voltage transformers and switchgear can be removed from buildings with lower voltage, DC power provided by the fuel cell systems.

Efficiency

Another benefit that stands out from both a financial and environmental standpoint is the efficiency of fuel cell systems. Conventional coal, petroleum, and natural gas power plants produce electricity at efficiencies between 27 percent and 42 percent. Combine those with transmission losses that average 17% and distribution losses that average 50 percent, the real efficiency of the systems are closer to 10 to 15 percent. Current Solid Oxide Fuel Cell (SOFC) system technology produces electricity at up to 60 percent efficiency. If the fuel cells are utilized in a Combined Heat and Power (CHP) system, the efficiency increases to over 90 percent. Utilizing these numbers, a simple comparison would be that to get the same power out of 100 cubic feet of natural gas used at a conventional natural gas power generator, a SOFC system utilizing CHP could require as little as 27 cubic feet of fuel. This substantial reduction of fossil fuel reduces costs and greatly reduces carbon emissions. From an environmental standpoint, not only is the carbon dioxide emissions reduced, but because the fuel cell systems do not involve combustion of the fuel, other pollutants such as nitrogen oxide and sulfur oxide emissions are negligible and particulate emissions are completely eliminated. In addition, because of the elimination of particulate and other effluents produced during the combustion process, carbon sequestration is greatly simplified and made more cost-effective. Alternate fuels such as methane and biogas can actually eliminate even greater amount of CO2.

Water Conservation

While concern over the limited fossil fuel resources have been at the forefront of media and environmentalists since the 1970s and global warming and CO2 emissions have captivated our attention since the 1980s, concern over fresh water has just recently been elevated to a similar level of urgency. While much attention has been given to the use of fossil fuels and the production of CO2 in the generation of electricity, few realize the impact power generation has on the world’s fresh water supply. In 2010, 161 billion gallons of water per day, over 45% of all water used in the United States, was used in conjunction with power generation. An average coal power plant uses over 5,000,000 gallons of water annually to produce of a single megawatt of power. Even the most efficient natural gas turbine generator plants utilize over 2,000,000 gallons of water annually to produce the same megawatt of electricity. SOFCs eliminate this draw on our fresh water supply by requiring less than 250 gallons of water at system start-up to produce the same megawatt of power. Once a fuel cell system is up and running, it produces nearly all of the water it requires through its electrochemical process, becoming self-sustaining from a water supply standpoint.

Disadvantages of Fuel Cells on Critical Facilities

While the main benefits are forward thinking and focused on efficiency, reliability, and eco-friendly, the disadvantages currently revolve around initial investment costs and the actual development of the fuel cell systems themselves.

Initial Investment Cost

As mentioned earlier, fuel cell technology as applied at a large scale, such as a system to generate power for buildings or campuses, has only really been around and in practice since the 1990s. Like many new technologies that enter the market place, the prototypes and initial systems are very costly and pose many questions on how long the components and systems will actually last. Although fuel cell systems are much more efficient that conventional power generation and distribution systems, the cost of the actual systems in addition to the fuel to produce the power is cost prohibitive to most smaller applications. As recently as 2013, the cost for one particular fuel cell system that is commonly used in commercial applications was estimated to be about $8,000 per kilowatt which would have a payback in excess of 10 years. New technological developments are looking into using different metal catalysts in lieu of platinum and other costly metals that could also produce much more power per surface area of the catalyst. Some estimates have the cost going as low as $1,000 per kilowatt with a two-year payback.

Durability and Lifespan

The technological developments that are driving the costs of the units also have an impact on the durability and lifespan of the systems. When systems costs have a payback period in excess of 10 years and the life expectancies of those systems are basically the same 10-year period, there is not much benefit beyond the reliability and environmental benefits. When the cost comes down and the system lifespan increases, the cost benefits increase significantly. Until systems become available and begin to be mass produced on a large scale, SOFC systems will probably only make a minimal impact on the power supply needs of society.

People in positions of power, including companies and the government, are poised to make a sweeping change that will impact society and our environment on a large scale.

Going Forward

What is critical when it comes to what electricity supports? Is it the hospital that treats the sick and injured? Is it the communications systems that enable first responders to aide those in need or a mother to check in on when her son is expected home from the library? Is it the data center that processes the international banking transactions or stores the selfies from a fifteen-year-old’s trip to an amusement park with her friends? Is it the refrigeration system that maintains the food supply for an entire community or the medications of the local pharmacy? Or is it the school that educates our youth and supports the research that makes the world a better place?

All of these functions are being supported by power either from the grid or provided at the point of use by fuel cell or co-generation facilities. It is our job to make sure that that power systems in the buildings we design are as reliable as possible and that it has as minimal an impact on our environment as possible. Critical is the important word when weighing advantages and disadvantages.

Bernie Woytek is a firmwide leader of Gensler's Mission Critical Practice. He earned a Bachelor of Environmental Design from Miami University, a Master of Architecture from the University of Virginia and a Master of Pastoral Studies from Loyola University, Chicago, and serves on the Oak Park Community Design Commission. Contact him at bernie_woytek@gensler.com.
Article originally appeared on architecture and design (http://www.gensleron.com/).
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