Putting Together a High-Efficiency, Reliable and Bankable Biogas-to-Power Plant 

Michael A. Devine
Gas Product/Marketing Manager with the Electric Power Gas Group of Caterpillar Inc.

May 2015
 
Introduction

Distributed generation is valuable in helping electric utilities deal with challenges of supply/demand balance, power quality, and infrastructure cost. A mong many benefits, small generating sources located near points of end use help forestall investments in central power plants, transmission lines and distribution systems. 

In recent years, natural-gas-fueled reciprocating engine-generators have proven highly suitable for distributed generation. They are economical to install and operate, extremely reliable, and relatively easy to site and permit. Increasingly, they offer a bonus benefit: In the right settings, the capture of heat from engine exhaust and fluids – combined heat and power (CHP) – makes the financial picture of distributed generation more appealing. 

When sited at or near a host facility with a significant heat demand, a generating system with heat recovery can supplement existing boilers or other heat sources. In these situations, it is not necessary to invest in sophisticated systems that wring the maximum available heat from the engines. The only requirement is that the value of the heat captured significantly exceeds the cost to install and maintain the heat recovery equipment.

As technology steadily improves engine efficiency and reduces emissions, it is increasingly worthwhile to weigh the advantages of CHP when considering distributed power installations.