An Exergy and Homeostatic Control Approach to Sustainable Grid-Connected Microgrids Without Energy Storage

This paper approaches the microgrid concept from a systemic and cybernetics viewpoint, as a viable sustainable energy system (SES) for supplying electricity and heat to small, rural communities in Chile. As such the microgrid may be viewed as a complex adaptive system (CAS) when connected to the grid and operating without energy storage, only with the grid as back-up power source. From an exergy and homeostatic control (HC) standpoint, one may analyze the microgrid as a socio-technical CAS when it is coupled with a set of homes and also connected to the grid; capable of supplying close to 80% of the daily residential consumer needs on average. Thus, under these conditions homes may draw inexpensive renewable electricity and heat from the microgrid if they are thrifty and efficient in their energy consumption; and they may also consume from the utility grid, yet at an expensive price. Based on this, an exergy and HC approach is proposed to develop such SES for rural and remote communities in Chile and South America, aiming to enhance energy efficiency (EE) and energy sustainability (ES). Under this scheme, renewable power (RP)-being a scarce, limited resource that must be managed efficiently-is supplied only to homes which comply with a specific criterion in an effort to curtail demand to ensure ES overtime. Simulation shows as expected that indeed certain criteria produce much better results than others in incentivizing thrifty, efficient energy consumption for small-size communities, without the need for expensive and sometimes polluting and forbidden energy storage systems. © (2014) Trans Tech Publications, Switzerland.