THE PROSPECTIVE AND POSSIBLE POTENTIAL OF SOLID OXIDE FUEL CELLS TECHNOLOGY

Kaggwa Abdul

Dept. Mechanical Engineering

National Chiao Tung University

1. Abstract

Over the past two decades, there has been tremendous progress on numerical and computational tools for fuel cells and energy systems. The purpose of this work is to analyse the current status of solid oxide fuel cell (SOFC) by Bloom Energy. In this report, a comprehensive literature survey on the prospect, potential market, business situation, commercialization and the core technology of SOFC systems modelling is presented.

Keywords: Solid Oxide Fuel Cells, Bloom Energy, Business situation and future markets.

2. Introduction

A solid Oxide Fuel Cell (SOFC) is a device that generates electricity through an electrochemical process that involves oxidation of the electrolyte when placed between the two electrodes - anode and cathode. According to the London and Edinburgh philosophical magazine and journal of Science [1] the first fuel cells were invented in 1838 by a Welsh physicist and barristerSir William Grove. The first commercial use of fuel cells came more than a century later inNASA space programs to generate power for probes, satellites and space capsules [2]. Since then, fuel cells have been used in many other applications. Fuel cells are used for primary and backup power for commercial, industrial and residential buildings and in remote or inaccessible areas. They are also used to powerfuel-cell vehicles, including forklifts, automobiles, buses, boats, motorcycles and submarines.

Fuel cells are generally categorized based on the type of electrolyte material used in them. SOFC uses a solid oxide or ceramic electrolyte. Some of the advantages of an SOFC include its low emissions, long-term stability, high efficiency, and fuel flexibility. Its high fuel flexibility permits the use of cheap, safe, and readily available fuels such as hydrocarbons, natural gas, hydrogen, methanol, and syngas [3]. An SOFC, however, requires a high operating temperature, usually within the range of 932 degrees to 1,832 degrees Fahrenheit, for the activation of the ceramics [4]. This high operating temperature leads to mechanical and chemical compatibility issues and longer start-up times. However the SOFC technology is a promising clean energy for the future and this can be proved by the involvement of number of mega industries namely; Toyota, Mitsubishi heavy industries, Rolls Royce, Ceres Power, mention but a few that are conducting research and development at their respective facilities.

3. How a solid oxide fuel cell works

In a solid oxide fuel cell, fuel is fed continuously to the anode which is a negatively charged electrode and an oxidant usually oxygen from air is fed continuously to the positively charged electrode cathode. The electrochemical reactions take place at the electrodes to produce an electric current through the electrolyte while driving a complementary electric current that performs work on the load.

Fig (1): Courtesy of ceramics.org

It should be noted that fuel cells are not limited by thermodynamic limitations of heat engines such as the Carnot efficiency because combustion is avoided and fuel cells produce power with minimal pollutant. However, unlike batteries the reductant and oxidant in fuel cells must be continuously replenished to allow continuous operation.

4. Commercialization and future potential of SOFC

According to PRNewswire [5], TheGlobal SOFC Market 2015-2019research report that covers the Americas, and the Europe, Middle East and Africa (EMEA) and Asia-Pacific (APAC) regions has been prepared based on the market analysis with inputs from industry experts. This report demonstrates the Global SOFC market landscape and its growth prospects in the coming years with a wide range of mega companies gaining interest in the business of SOFC. These Companies include;Acumentrics, Bloom Energy, Fuel Cell Energy, Mitsubishi Heavy Industries, ADELAN U.K., Alstom, Ceramic Fuel Cells, Ceres Power, Delphi SOFC Technology, Elcogen, Hexis, Protonex, Rolls-Royce, SOFC power, Sunfire, Topsoe Fuel Cell, Ultra Electronics AMI, WATT Fuel Cell, and Toyota.

According to global market [6] Global fuel cell deliveries have grown annually close to 40% since 2006 and over 50% growth in 2012. SOFC seen as future winner due to better cost potential. Stationary SOFC started to replace PEMFC in residential applications and this demonstrates fuel cell market potential and expectations are high.

Fig (2)

4.1. Bloom Energy

4.1.1. Company History

Bloom Energy traces its roots to work performed by Dr. K.R. Sridhar, Bloom founder and Chief Executive Officer, in connection with creating a technology to convert Martian atmospheric gases to oxygen for propulsion and life support [7]. Dr. Sridhar and his team built a fuel cell capable of producing air and fuel from electricity generated by a solar panel. They soon realized that their technology could have an even greater impact here on Earth.

In 2001, the team decided to advance their research and start a company originally called Ion America and later Bloom Energy was founded with the mission to make clean, reliable energy affordable for everyone on earth.

In 2002, with financing in place from investors, the team packed three U-hauls and headed to NASA Ames Research Center in Silicon Valley to set up shop. Over the next few years, the technology quickly developed from concept, to prototype, to product, as the major technological challenges were solved and the systems became more powerful, more efficient, more reliable, and more economical [8].

In early 2006 Bloom shipped its first 5kW field trial unit to the University of Tennessee, Chattanooga. After two years of successful field trials in Tennessee, California, and Alaska, to validate the technology, the first commercial (100kW) products were shipped to Google in July 2008. Since that time Bloom's Energy Servers have helped some companies to generate millions of kilowatt-hours of electricity and eliminate millions of pounds of carbon dioxide emissions from the environment.

4.1.2. The Bloom Box / servers.

Bloom Energy has developed a revolutionary on-site primary power generation system. The Bloom Energy Server is based on a proprietary fuel cell technology that provides a more reliable, cleaner, and cost effective alternative to the traditional electric grid. Bloom provides a transformational new data centre topology that greatly simplifies the architecture and eliminates the need for many legacy components.

Fig (3)

The technology is based on a solid oxide fuel cell platform with roots in the NASA Mars Program [9]. The Bloom Energy Server converts fuel into electricity through a clean and efficient electro-chemical process that emits significantly less greenhouse gases, nitrogen oxide (NOx), sulfur oxide (SOx), and particulate matter than conventional combustion technologies. The system is fuel flexible and can run on natural gas for significant greenhouse gas reductions, or biogas for a carbon neutral solution

What’s in the Bloom Energy Server?

The bloom Energy servers comprise of many components such as stack, module and fuel cell as shown if Fig (4).

Fig (4)

How bloom energy servers create electricity

A single fuel cell consists of an anode, a cathode, and an electrolyte stuck between the two. As fuel flows in through the anode side and an oxidant comes in over the cathode, a reaction is triggered that causes electrons to move into the fuel cell's circuit, producing electricity. According to bloom report each server produces 100 kW of power, consists of thousands of fuel cells, costs between $700,000 and $800,000, and pays for itself in three to 5 years based on an energy cost of 8 to 9 cents per kW hour.

Fig (5)

The Bloom Energy Server architecture provides building blocks that enhance reliability, Extended outage protection Eliminates surges, sags or interference, Highly modular, scalable design, Predictable electricity costs, 24 x 7 Uninterruptible Power, availability of the BE solution = 99.998%, Concurrently maintainable, Highly redundant design, fault tolerant, Hot swappable field replacement units, Eliminates the risk of power over-provisioning

Fig (6)

4.1.3.

Potential clients and the market for Bloom as of early 2015.

In 2003-2007, the company’s research and development field trials were validated and huge success was achieved. Early 2008, Bloom made its very first shipment to Google as their first client. Since then very many companies have gained interest in the bloom box servers as a way of reducing emissions to the atmosphere. According to Bloom energy report [10] of 2014 Bloom extended their technology by installing bases that reach 140MW to multiple sites in Japan.


4.1.4. The Future of SOFC referring to Bloom energy’s plans and progress.

According to Spruce Investment [11] millions in private funding continues to roll in for Bloom Energy, the latest cash infusion is $130 million, raised from undisclosed investors. The company board members and executives are suggesting going for International public offering (IPO). This is going to enable the company sell shares internationally hence leading to more capital for investment and their estimation is approximately $1.2 billion.

Green tech media [12] Bloom is looking to raise $160 million in the form of convertible notes, of which about $130 million had been raised. The company has raised more than $1.2 billion, has a roster of premier paying customers, and a knack for absorbing state subsidies intended for clean, renewable power. The 11-year-old startup claims to have installed more than 130 megawatts of its Bloom boxes in the U.S. Venture wire [13] Bloom took $ 50 million from The New Zealand Superannuation Fund, whileExelon, the Chicago-based competitive energy provider, agreed to finance 21 megawatts of Bloom's fuel-cell deployments in any state with a favorable subsidy regime. Bloom has an electricity sales business, Bloom Electrons, which eliminates much of the risk for the customer, as well as a leasing and ownership structure. Figure (7) illustrates the aggregate funding of companies versus Bloom Energy funding.

Fig: (7)

According to advanced energy economy [14] this is the third annual report of market size, by revenue, of the advanced energy industry, worldwide and in the United States. Prepared for AEE by Navigant Research, Advanced Energy Now 2015 Market Report is the most comprehensive assessment of advanced energy markets ever compiled. With nearly $200 billion in 2014 revenue, the U.S. advanced energy market is bigger than the airline industry, equal to pharmaceuticals, and almost equal to consumer electronics.

Fig (8)

5. Challenges of SOFC

In the grand scheme of energy technologies, the key component that makes up a fuel cell that is like a chemical battery that produces electricity is relatively short-lived. This Achilles heel is one of the main reasons that building, installing and selling fuel cells can be so expensive and almost none of the fuel cell makers are profitable yet.

There are different types of fuel cells but in general the stacks that make up a fuel cell and create the reaction that produces electricity often last only about two to five years. This is common for different types of fuel cells like solid oxide fuel cells that Bloom Energy makes. A fuel cell’s stacks fill a chamber called the hot box, and it’s this chamber that gets swapped out of these fuel cells for a few years. The stack contains a catalyst often platinum which when combined with the fuel source (natural gas or hydrogen) and oxygen creates electricity.

Fig (9)

Break down

Gigaom independent analysts [15] over time, as the fuel and oxygen are constantly being pumped in and run over the catalyst in the stacks, the chemicals start to degrade and the system starts to wear down. Fuel cells also run at high temperatures, which is another reason these systems degrade quickly. The short life span of the hot box is a key problem for the capital costs of fuel cell makers. The hot box can make up a significant portion of the fuel cell, as high as 50 to 75 percent of the cost of the system.

Costs Climb

Fuel cell makers are spending a lot on R&D trying to find these stack lifetime breakthroughs, but are also looking to reduce costs via reaching economies of scale and manufacturing. The idea is even if the stacks don’t last longer in the future, they can ultimately be cheaper to produce. Bloom Energy has been scaling up manufacturing of its solid oxide fuel cells.

Fig (10)

6. Future Applications of Solid Oxide Fuel Cell

Like molten carbonate fuel cells, solid oxide cells require high operating temperatures, and their most common application is in large, stationary power plants. The high temperatures open the opportunity for cogeneration using waste heat to generate steam for space heating, industrial processing, or in a steam turbine to make more electricity. There is no doubt that the technology will be used in automotive Fig (11) where by hydrogen storage tank loaded to the automobile stores hydrogen gas compressed at extremely high pressure to increase driving range.

Fig: (11)

7. Conclusion

Fuel cell technology started long time ago over 100 years, but of recent, due to the major global need for clean energy has sparked very many institutions that include mega companies and research institutes. However, the technology is still young in terms of global market and commercialization due to its range of challenges for example high temperatures that lead to production or manufacturing costs are still high.
Bloom Energy through the works of Dr. K.R. Sridhar was created and it has been financed by both the federal government and some powerful financially stable investors and due to these funding sources, Bloom has been able to build the bloom Box/servers that produce up to 100KW. These servers have attracted very many potential clients and the recent is Japan where it installed the Bloom box of 140MW.