China Energy Group Affiliate and retired Berkeley Lab Staff Scientist Chris Marnay organized and led the Tianjin 2014 Symposium on Microgrids in Tianjin, China on November 13-14. This was Dr. Marny's tenth Microgrid Symposium as chairman. This symposium is a series that dates back to the first on the U.C. Berkeley Campus in 2005, with others in Montreal, Nagoya, Kythnos Is., Greece, San Diego, Jeji Is., South Korea, Évora, Portugal, and Santiago, Chile. About 110 of the world's leading experts on microgrids from 20 countries attended the 2-day symposium this year, hosted by Tianjin University and sponsored by the U.S. Department of Energy, the Energy Foundation, and several other organizations.
Microgrids are small power systems, from a single house to a college campus in size, that can function connected to our familiar power grid, or as an electrical island depending on its own local sources of energy while controlling its own devices and storage. Attendees shared experiences from microgrid demonstration projects from Europe, the Americas, and Asia.
Microgrids under discussion at this symposium partially decouple loads and dispersed resources from the highly centralized megagrid (the tightly controlled power grid upstream of substations) and manage all energy sources (electrical, thermal, etc.) and delivery of energy services (heat, light, cooling, etc.) locally. Marnay said they can potentially apply all available assets using all capabilities from both local and central sources, and choose technologies that best meet their objectives (be they cost, efficiency, environmental stewardship, or most likely, a combination), while tailoring the quality of energy delivered to devices to match their highly heterogeneous delivered energy service requirements.
Dr. Marnay pointed out that such systems offer many advantages over our current long-distance energy delivery infrastructure operating under a highly centralized control scheme. Local systems can be tailored to best meet local needs, particularly ensuring that vital services are powered under all circumstances. Available environmentally benign resources not available at a scale of interest to the megagrid can be beneficially used, cleaning the air and water. According to Marnay, by tailoring the quality of energy delivered, wasteful use of costly high quality resources is avoided, saving money. Even thermal power generation is often best done on a relatively small scale in combined heating a cooling plants that use the waste heat lost at large power stations effectively, e.g. to heat and cool buildings.
Marnay added that since we now appreciate the added resiliency of decentralized systems, such as the internet, in many countries, especially the U.S. and Japan, a major microgrid motivator is more dependable energy supply during and after natural disasters. He said demonstration projects such as the one in Sendai Japan and the one at Princeton University performed admirably after the 2011 earthquake and tsunami and 2012's Superstorm Sandy. By protecting important loads locally, expansion of the traditional megagrid can be avoided, and it can be reoriented towards our vital need to accommodate more clean power generation into the grid, and to open it to competitive electricity supply. Marnay suggested that for China particularly, with its rapidly expanding energy needs and severe environmental problems, microgrids provide one of the promising new opportunities for it to meet its recently announced carbon reduction goals, improve the quality of the environment, and materially improve citizens' lives.