As the aging grid is increasingly strained by higher peak loads, it often fails to distribute power reliably from centralized generation. That’s one key reason microgrids are becoming mainstays for military installations, hospitals, and other facilities that can’t risk losing power. These facilities use microgrids to switch between grid-tied and “islanding” modes. Integrating more microgrids with the grid can help ease this pressing reliability problem. For instance, when used as dispatchable assets, distributed energy resources (DERs) supplied by microgrids greatly improve grid stability by islanding away significant portions of load during peak demand periods.
But to integrate microgrids on a broad scale, we must overcome multiple challenges, from the interoperability issues inherent to “brownfields” to the imperative for grid-wide interconnection standards and regulatory changes. Because these challenges impede microgrid integration, they inhibit the use of assets that could significantly increase grid reliability, stability, efficiency, and capacity.
Most microgrids today are retrofit projects on brownfield sites. These sites contain legacy assets which require an overlay of intelligent new control and communication technologies for integration with core microgrid components, such as renewable energy generation and energy storage systems. Achieving interoperability between the old and the new is no small feat. It requires phasing in smart grid solutions with the help of a microgrid provider and integration expert such as S&C Electric.
Problems of Interconnection
Due to their technically complex and resource-intensive retrofits, brownfields present one of the biggest obstacles to integrate microgrids in an expedient, cost-effective manner. Fortunately, in the near future, more microgrids will be developed on “greenfields” where the interoperability challenges posed by legacy systems are virtually absent as developers integrate microgrid planning and the U.S. Green Building Council’s Performance Excellence in Electricity Renewal (PEER) design concepts into new construction.
The lack of established grid interconnection standards will continue to make microgrid integration difficult too. Grid-wide protocols for simple, safe, beneficial interconnection are urgently needed. Not only are such standards key to the performance of the systems being coupled, they will help harness the economic potential of both the microgrid and the interconnected system. To date, IEEE has developed the most pertinent standards for microgrids and their interconnection to the grid, and they continue to work on advancing these standards.
Adopted in 2003, IEEE 1547, “Standard for Interconnected Distributed Resources with Electric Power Systems,” articulated requirements for interconnecting DERs with the grid—it focused on testing, operation, maintenance, and safety. In 2011, IEEE approved 1547.4, “Guide for Design, Operation, and Integration of Distributed Resource Island Systems with Electric Power Systems,” offering best practices for islanding and reconnecting DERs to the grid without disrupting service. Recently amended, IEEE 1547 is evolving to address microgrid interconnection and higher DER penetrations. But standards still need to catch up with rapidly advancing microgrid technology.
Results-based regulations, which reward utilities for performance and operational efficiencies that deliver long-term benefits to customers, must also be enacted to boost investments in microgrids. States should also ensure that regulations keep pace with interconnection standards so utilities have the support and incentives needed to integrate microgrids. More funding is critical to continued progress too. In February, the U.S. Department of Energy announced $7 million in funding to advance the design of community-scale microgrids with capacities up to 10 MW, an initiative that will fortify the grid.
As more microgrids are deployed, it becomes even more important to have grid-wide standards and regulations in place. Of North America’s 2.87 GW of microgrid capacity, 1.54 GW operates in “grid connected mode” the majority of the time according to Navigant Research. In addition, Navigant estimates that global annual microgrid capacity will exceed 4 GW by 2020, up from 685 MW in 2013, with North America as the largest market. More proactive steps must be taken now to address the challenges and ensure beneficial, broad-scale integration of microgrids in North America and beyond.
What are the biggest obstacles to integrate microgrids in North America? Worldwide? Share your thoughts in the comments area or join the debate on the Microgrid Knowledge LinkedIn Group.
This article was written by David Chiesa, the director of business development for S&C Electric Company’s Commercial, Industrial, Government and Microgrid market segment. An earlier version of this article appeared on GridTalk and was reprinted with permission from S&C Electric.