Optimizal Design and Control Strategies for Novel Combined Heat and Power (CHP) Fuel Cell Systems: Part II of II—Case Study Results

Innovative energy system optimization models are deployed to evaluate novel fuel cell system (FCS) operating strategies, not typically pursued by commercial industry. Most FCS today are installed according to a “business-as-usual” approach: 1) stand-alone (unconnected to district heating networks and low-voltage electricity distribution lines), 2) not load following (not producing output equivalent to the instantaneous electrical or thermal demand of surrounding buildings), 3) employing a fairly fixed heat-to-power ratio (producing heat and electricity in a relatively constant ratio to each other), and 4) producing only electricity and no recoverable heat. By contrast, models discussed here consider novel approaches as well. Novel approaches include 1) networking (connecting FCSs to electrical and/or thermal networks), 2) load following (having FCSs produce only the instantaneous electricity or heat demanded by surrounding buildings), 3) employing a variable heat-to-power ratio (such that FCS can vary the ratio of heat and electricity they produce), 4) co-generation (combining the production of electricity and recoverable heat), 5) permutations of these together, and 6) permutations of these combined with more “business-as-usual” approaches. (The detailed assumptions and methods behind these models are described in Part I of this article pair. Reprinted from Part 1, TABLE 1 below summarizes twelve novel operating strategies investigated by the models.