In addition to reducing carbon footprint, empowering customers to more cost-efficiently manage their energy usage and fueling new business opportunities, the Smart Grid offers tremendous promise in terms of improving the reliability and availability of electricity service. Increased reliance on “microgrids” is one way how.
In a microgrid, a utility concentrates perhaps a wide array of distributed-generation technologies—diesel, fuel cells, natural-gas-fired turbines and microturbines, photovoltaic fields, solar-thermal stations, wind farms and other resources—in a cluster that could be used in different valuable ways. The utility might typically keep the microgrid connected to the centralized grid for helping fulfill normal demand but disconnect it to operate on its own and maintain service to key application sectors (such as hospitals and emergency services) during a reliability issue. Or, the microgrid might normally be “islanded” from the centralized grid and kept available for as-needed utilization during an event such as a grid shutdown, breach, period of unreliability or another abnormal condition.
Two-way communications and control across the electricity-delivery facility is necessary to synchronize between the microgrid and traditional grid, in order to ensure a successful switch of the microgrid’s mode of operation between connected and disconnected. End to end—from a utility’s operation center to all of its remote substations—there must exist sophisticated capabilities for management and protection in order to ensure that the transition takes place automatically, efficiently, non-disruptively and safely. The microgrid system, for example, might be configured to respond to a signal of a droop in voltage. In the event of such a fault, the centralized grid might close itself to an impacted sector, with the microgrid being activated (within microseconds) to keep power flowing to the users in that islanded sector.
Microgrid pilots are already underway in some areas of the world, and the data that these experiments yield will go a long way in determining the eagerness of private investors to fund larger-scale deployments. Utilities in California, for example, are assessing microgrids’ potential for avoiding blackouts, better managing peak-demand periods and supporting a more resilient, self-healing infrastructure.
Technology and standards development in the coming years will enhance microgrids’ usefulness to utilities.
Energy storage, for example, is a great frontier of innovation, and more robust technologies in this area would allow microgrids to make greater use of inherently intermittent, renewable sources of energy. The interconnection environment is maturing, too, with the rollout of globally relevant standards that will help utilities efficiently overcome traditional barriers such as geographic borders and vendor interoperability.
Important business and regulatory questions—particularly around the cost of interconnection—must be addressed, too. How will that cost be split among providers of distributed-generation energy sources and clusters and the utilities who employ those resources through microgrids? Greater clarity in these high-stakes business/regulatory areas would stand to accelerate development of microgrids specifically, as well as other elements of the greater Smart Grid.
Photo by Microgrids EU.