The CERTS Microgrid and the Future of the Macrogrid
The blackouts of summer 2003 underscored the dependence of western economies on reliable supply of electricity with tight tolerances of quality. While demand for electricity continues to grow, expansion of the traditional electricity supply system is constrained and is unlikely to keep pace with the growing thirst western economies have for electricity. Furthermore, no compelling case has been made that perpetual improvement in the overall power quality and reliability (PQR) delivered is possible or desirable. An alternative path to providing for sensitive loads is to provide for generation close to them. This would alleviate the pressure for endless improvement in grid PQR and might allow the establishment of a sounder economically based level of universal grid service.
Providing for loads by means of local power generation is becoming increasingly competitive with central station generation for a number of reasons, four key ones being nontechnical constraints on expansion of the grid, improvements in small scale technologies, opportunities for CHP application, and the ubiquitous nature of sensitive loads in advanced economies. Along with these new technologies, concepts for operating them partially under local control in microgrids are emerging, the CERTS Microgrid being one example. It has been demonstrated in simulation, and a laboratory test of a three microturbine system is planned for early 2005, to be followed by a field demonstration. A systemic energy analysis of a southern California naval base building demonstrates a current economic on-site power opportunity.