Economic Analysis of Distributed Generation Options With Wide Turndown

Solid oxide fuel cell gas turbine (SOFCGT) hybrid systems have received much attention due to high predicted efficiencies, low emissions and low historical cost of natural gas. For market acceptance three criteria must be met: reliability, commercial availability and a positive net present value. This study deals primarily with the latter, comparing the net present value of the following four engines operating under a distributed or isolated loads: a simple cycle microturbine, a novel internally-cooled and recuperated (ICR) microturbine, a novel SOFCGT hybrid supported by the same ICR microturbine, and a standard diesel engine. Due to the higher value of peak power, a system able to meet fluctuating power demands while retaining high efficiencies is strongly preferable to base load operation. Sensitivity analysis is made for variable prices of natural gas, electric rates, carbon tax, and SOFC capital costs.