Solid Oxide Fuel Cell Technology Stationary Power Application Project
The objectives of this program were to: (1) Develop a reliable, cost-effective, and production-friendly technique to apply the power-enhancing layer at the interface of the air electrode and electrolyte of the Siemens SOFC; (2) Design, build, install, and operate in the field two 5 kWe SOFC systems fabricated with the state-of-the-art cylindrical, tubular cell and bundle technology and incorporating advanced module design features. Siemens successfully demonstrated, first in a number of single cell tests and subsequently in a 48-cell bundle test, a significant power enhancement by employing a power-enhancing composite interlayer at the interface between the air electrode and electrolyte. While successful from a cell power enhancement perspective, the interlayer application process was not suitable for mass manufacturing. The application process was of inconsistent quality, labor intensive, and did not have an acceptable yield. This program evaluated the technical feasibility of four interlayer application techniques. The candidate techniques were selected based on their potential to achieve the technical requirements of the interlayer, to minimize costs (both labor and material), and suitably for large-scale manufacturing. Preliminary screening, utilizing lessons learned in manufacturing tubular cells, narrowed the candidate processes to two, ink-roller coating (IRC) and dip coating (DC). Prototype fixtures were successfully built and utilized to further evaluate the two candidate processes for applying the interlayer to the high power density Delta8 cell geometry. The electrical performance of interlayer cells manufactured via the candidate processes was validated. Dip coating was eventually selected as the application technique of choice for applying the interlayer to the high power Delta8 cell. The technical readiness of the DC process and product quality was successfully and repeatedly demonstrated, and its throughput and cost are amenable to large scale manufacturing. Two 5 kWe-class SOFC power systems were built and installed for the purpose of testing and evaluating state-of-the-art tubular cell and bundle technologies, advanced generator and module design features, balance-of-plant components, and cost reduction measures. Installed at the Phipps Conservatory and Botanical Gardens, a system operated for more than 17,500 hrs, delivering electrical power to the on-site grid and thermal energy in form of hot water for onsite utilization. Operation was typically autonomous, requiring minimal operator intervention, and achieved an overall availability of greater than 85%. Outages were primarily due to an unstable local grid, two weather related outages were experienced, and very few reliability issues were encountered despite harsh operating conditions. No repairs to the stack, module, or balance-of-plant were required. A second system was designed, built, delivered, and installed at a Siemens facility in Charlotte, North Carolina. Operational issues associated with the balance-of-plant were encountered during startup and prevented the system from operating.
- Research Organization:
- Siemens Energy, Incorporated
- Sponsoring Organization:
- USDOE
- DOE Contract Number:
- FC26-06NT42810
- OSTI ID:
- 970599
- Country of Publication:
- United States
- Language:
- English
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