A Unique Solution to Low Cost SOFC Hybrid Power Plant

Abstract

The inherently clean and efficient nature of fuel cell systems makes them highly attractive for electrical power generation applications, subject to overcoming their disadvantage of high initial cost. Rolls Royce has been working for 10 years to create a fuel cell stack design of much lower cost, having a structure both tolerant to sharp changes in operating temperature and fully durable when used in load-following applications requiring moderate cycling of stack conditions. The effort was launched as a company supported research initiative but has also attracted substantial European Commission funding, with emphasis on developing low manufacture cost stack technologies. This paper describes how chemical and physical features of the stack, and the technologies selected for the integrated plant system, have achieved major strides in cost reduction. The design and development of the system using this technology has been transitioned to an European/USA industry development team whose goal is commercialization of the product within five years. Manufacture will use both European and USA facilities. Market opportunities for fuel cell hybrids are briefly discussed.

Modelling of Pressurised Hybrid Systems Based on Integrated Planar Solid Oxide Fuel Cell (IP‐SOFC) Technology

“…At the moment, all the models are used for the complete analysis (from the electrochemical cell analysis to the start-up system control) of the new RRFCS hybrid system, based on IP-SOFC technology and on the heat exchangerless design, as discussed by [25].…”

“…For the sub MW and 1±2 MW systems, it is possible to vary the rotational speed of the gas turbine [25], adapting the air mass flow rate to ambient conditions, in order to keep the stack temperature constant. The results are shown in Figure 16 and in Figure 17 for the first and second system, respectively.…”

Predicting the ultimate potential of natural gas SOFC power cycles with CO 2 capture – Part A: Methodology and reference cases

“…In order to avoid excessive thermal stresses through the fuel cell, gas temperature increase along the stack should be limited. To this end, heat can be recovered from the gases leaving the fuel cell (or the combustor if adopted) by means of high temperature heat exchangers (600e800 C) [26,30,51] or by recycling and mixing part of the cathode exhaust with fresh air [52,53]. While the first option implies the use of expensive material, the second requires the adoption of an ejector to sustain the recycle, thus increasing the auxiliary electric consumptions (fresh air needs to be pressurized to serve as primary driving gas in the ejector).…”