DE technologies have a range of technical characteristics, making different technologies more suitable in specific applications, depending on whether the determining criterion is electrical output, provision of usable heat, fuel availability, reliability, or emission levels, to name just a few criteria. However, all DE technologies have the capacity to be remotely operated and controlled. This is achieved through monitoring a range of operating parameters via a
communication link and allows simplified maintenance, avoids unexpected shutdowns, and eases the grid control issues that arise from locating DE units within the electric distribution network. Another common characteristic of DE technologies is that following factory fabrication they are straightforward to install, thus minimizing implementation costs.
A useful parameter when comparing DE technologies is the heat to power ratio (HPR). This is the ratio between heat use and electricity generation in a CHP application. For example, if electric and total efficiencies are 30 and 80%, respectively, then HPR = (80—30)/30, or 1.67. Depending on the application, electrical or thermal output may be valued or required. Also, note that all electrical efficiencies in this article are quoted as higher heating value (HHV). This includes the heat of vaporization of water. For natural gas, HHV efficiency = Lower Heating Value efficiency/1.1.
This section provides a brief overview of the major DE technologies, discusses their principal strengths and weaknesses, and provides a quantitative comparison of their technical characteristics (see Tables I and II). This section is designed to be illustrative as site-specific variation, differing models, and continuing technical progress will alter these characteristics. Economic and environmental comparisons are detailed in Sections 6 and 7.