Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Big box stores could ditch the grid, use natural gas fuel cells instead

05.03.2015

Study finds potential for reduced carbon emissions and lower power costs

Large facilities like big box stores or hospitals could keep the lights on by using a fuel cell that runs off the natural gas that already flows in pipelines below most city streets.


Natural gas powered solid oxide fuel cells, located at the point of use to produce electricity for facilities the size of big box stores, could provide economic and environmental benefits, with additional research, according to new study.

Credit: Pacific Northwest National Laboratory

Instead of drawing electricity from the power grid, facilities could use natural gas-powered solid oxide fuel cells to lower their electric costs, increase power reliability, reduce greenhouse gas emissions, and maybe even offset costs by selling excess fuel cell-generated power back to the power grid. Such an energy future could be possible -- assuming fuel cell lifespans are improved and enough systems are produced to reach economies of scale -- according to a cost-benefit analysis published in the journal Fuel Cells.

If such advances are made, researchers at the Department of Energy's Pacific Northwest National Laboratory conclude natural gas solid oxide fuel cells could play a significant role in meeting future energy demand. The technology could help meet the 10 percent increase in electricity the nation will need in the next decade. That estimate, by the U.S. Energy Information Administration, will require 68 gigawatts more generating capacity.

PNNL's study focused on distributed generation, where fuel cells are located right at the individual facilities they power. This is different than the traditional central generation approach to energy, where large power plants are often located far away from end users.

Instead of burning fuel like combustion engines, solid oxide fuel cells oxidize it electrochemically. Each cell is made of ceramic materials, which form three layers - an anode, a cathode and a solid electrolyte, much like a battery. Multiple cells must be assembled into a fuel cell stack to achieve the desired power output.

Solid oxide fuel cells are inherently highly efficient in converting fossil fuels to electrical energy and PNNL's unique system design, which includes anode recycling, steam reforming, and pressurization, advances the technology even further.

"On the anode side of the fuel cell, we recycle waste heat in a steam reformer to squeeze even more energy out of the fuel - about 25 percent more chemical energy compared to typical solid oxide fuel systems," said Larry Chick a materials engineer at PNNL. "The stack operates under high pressure - about the equivalent of being 230 feet under water. That increases the power density, which reduces the size of the stack by about 60 percent and lowers the fuel cell's overall cost significantly."

The researchers based their cost modeling study on a small-scale solid oxide fuel cell system designed, built, and tested at PNNL and a larger conceptual system of 270 kilowatts, which is enough to power a large retail facility or light industry. Cost estimates are expressed in 2012 dollars.

The study showed that for the same power output, a natural gas fuel cell would cost almost one-third less to build than a centralized natural gas combined cycle plant.

"We were intentionally conservative as we calculated the cost of both building and operating natural gas solid oxide fuel cells and other types of generation," said PNNL economist Mark Weimar. "For instance, in comparing the solid oxide fuel cell to a 400 megawatt natural gas combined cycle plant, we assumed that the larger, central generation plant would pay cheaper wholesale prices for natural gas compared to smaller, distributed generation fuel cells, which we estimated would pay retail or almost double the wholesale cost."

The authors report that if stack life improvements are made and mass manufacturing is achieved, natural gas solid oxide fuel cells can be cost-competitive with natural gas combined cycle plants, which are projected to generate electricity at a total cost of 6.5 cents per KWh. They calculated natural gas fuel cells would have a total electricity cost of 8.2 cents per kWh.

When researchers factored in the additional benefits of distributed generation, it brought the cost down to 5.3 cents per kWh. Those benefits stem from the fact that fuel cells don't have the extra costs and power losses associated with transmission and distribution power lines that central power plants experience.

Higher efficiency, lower emissions

The high efficiency of natural gas fuel cells means fewer greenhouse gas emissions as well. The PNNL prototype showed 56 percent electrical conversion efficiency compared to 32 percent from conventional coal plants and 53 percent from natural gas combined cycle plants. The study shows that the natural gas fuel cell system would produce 15 percent less carbon dioxide per kWh than a modern natural gas combined cycle power plant.

Additionally, since a distributed generation natural gas fuel cell system would be installed on site, some of the heat from the fuel cell could be used to heat water or interior spaces. If just 20 percent of the fuel cell heat replaced the use of grid electricity for heating, then the fuel cell system would produce 22 percent less carbon dioxide than large-scale natural gas combined cycle plants tied to the grid.

Currently, fuel cell stacks last only about two years. Over time, as the fuel and oxygen are constantly being pumped in and run over the catalyst in the cells, the chemicals start to degrade and the system starts to wear down. The study noted fuel cell stacks would need to last six to eight years to be competitive, and uses a15-year lifespan in the study's cost comparison table.

With additional research, the limited stack life can be overcome," Chick said. "It's a matter of conducting reliability testing on integrated systems and using advanced characterization techniques to figure out what is degrading the performance of the stacks over time. The Department of Energy's Solid Oxide Fuel Cell program has been achieving targeted improvements over the last decade, so things are moving in the right direction."

###

Reference: Chick, L., Weimar, M., Whyatt, G. and Powell, M. (2015), The Case for Natural Gas Fueled Solid Oxide Fuel Cell Power Systems for Distributed Generation. Fuel Cells, 15: 49-60. DOI: 10.1002/fuce.201400103

http://onlinelibrary.wiley.com/doi/10.1002/fuce.201400103/full

nterdisciplinary teams at Pacific Northwest National Laboratory address many of America's most pressing issues in energy, the environment and national security through advances in basic and applied science. Founded in 1965, PNNL employs 4,300 staff and has an annual budget of more than $1 billion. It is managed by Battelle for the U.S. Department of Energy's Office of Science. As the single largest supporter of basic research in the physical sciences in the United States, the Office of Science is working to address some of the most pressing challenges of our time. For more information on PNNL, visit the PNNL News Center, or follow PNNL on Facebook, Google+, LinkedIn and Twitter.

Media Contact

Susan Bauer
susan.bauer@mac.com
509-372-6083

 @PNNLNews

http://www.pnnl.gov/news 

Susan Bauer | EurekAlert!

More articles from Life Sciences:

nachricht Nanoparticle Exposure Can Awaken Dormant Viruses in the Lungs
16.01.2017 | Helmholtz Zentrum München - Deutsches Forschungszentrum für Gesundheit und Umwelt

nachricht Cholera bacteria infect more effectively with a simple twist of shape
13.01.2017 | Princeton University

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.

While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...

Im Focus: Studying fundamental particles in materials

Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales

Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...

Im Focus: Designing Architecture with Solar Building Envelopes

Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.

As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...

Im Focus: How to inflate a hardened concrete shell with a weight of 80 t

At TU Wien, an alternative for resource intensive formwork for the construction of concrete domes was developed. It is now used in a test dome for the Austrian Federal Railways Infrastructure (ÖBB Infrastruktur).

Concrete shells are efficient structures, but not very resource efficient. The formwork for the construction of concrete domes alone requires a high amount of...

Im Focus: Bacterial Pac Man molecule snaps at sugar

Many pathogens use certain sugar compounds from their host to help conceal themselves against the immune system. Scientists at the University of Bonn have now, in cooperation with researchers at the University of York in the United Kingdom, analyzed the dynamics of a bacterial molecule that is involved in this process. They demonstrate that the protein grabs onto the sugar molecule with a Pac Man-like chewing motion and holds it until it can be used. Their results could help design therapeutics that could make the protein poorer at grabbing and holding and hence compromise the pathogen in the host. The study has now been published in “Biophysical Journal”.

The cells of the mouth, nose and intestinal mucosa produce large quantities of a chemical called sialic acid. Many bacteria possess a special transport system...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

Nothing will happen without batteries making it happen!

05.01.2017 | Event News

 
Latest News

Water - as the underlying driver of the Earth’s carbon cycle

17.01.2017 | Earth Sciences

Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

17.01.2017 | Materials Sciences

Smart homes will “LISTEN” to your voice

17.01.2017 | Architecture and Construction

VideoLinks
B2B-VideoLinks
More VideoLinks >>>