BY Kevin Meagher & Ken Wood, EDSA
Since the term smart grid first appeared in 2005, it has become almost synonymous with another term used to describe something priceless and eternally evasive—Holy Grail. Although engineers, venture capitalists and politicians have evangelized the vision of an intelligent, dynamic and self-healing power grid, building even a single working prototype has been slow. The reason? The software technology that would allow thousands of local and grid-level power system data points to be monitored in real-time, diagnosed for accuracy and stability, and acted upon in an intelligent manner did not exist. Until this year, even the most optimistic experts believed that, even with a well-planned, well-funded and well-staffed software development effort, the software missing link, called a master controller, was at least three to five years away.
The future appears to have arrived earlier than planned, however, after the California Department of Energy issued its 2009 Renewable Energy Secure Communities (RESCO) solicitation: Among more than 50 proposals was an innovative public/private approach submitted by University of California San Diego (UCSD) that leveraged its on-campus alternative power infrastructure with existing off-the-shelf commercial software technologies from two established software developers: San Diego’s EDSA and Philadelphia’s Viridity Energy.
Prodding the Vision of Perfect Power
The original goal of the RESCO solicitation was to identify emerging technologies that could improve the California power grid’s reliability statewide, while promoting energy efficiency. One technology that was of particular interest was distributed energy resources (DERs) in the form of microgrids. A microgrid is a self-sustaining power grid serving a single campus, like the physical grounds of a private corporation, a government facility or a university campus that uses some combination of co-generation, solar, wind, battery or other form of energy to meet most of its power needs. A microgrid can connect and disconnect from the grid, enabling it to operate in both grid-connected or island-mode. Some of its many benefits include:
- Enabling grid modernization by integrating multiple smart grid technologies.
- Enhancing DER integration.
- Meeting end-user needs like power quality and energy independence.
- Supporting the larger grid by enabling flexible handling.
Microgrids are connected to a larger public grid forming a network of private and public power generation facilities that—if a software “master controller” were in place to manage the interoperability between them—would result in a seamless public-private power cooperative.
Depending on real-time operating conditions, the amount of power that can be generated on-site, demand, utility availability, and the power’s cost, microgrid owners could opt in (purchase utility power, or sell excess power back to the public utility) or opt out (operate in self-sustaining mode) of their local utility grid as their local power situation changes.
Stage No. 1: Perfect Power Defined
Perfect power’s core value proposition is to enable consumers to manage their electricity use so they can optimize the convenience, cost and service reliability at all times. Bob Galvin and Kurt Yeager of the Galvin Electricity Initiative (GEI) describe perfect power as:
- A power delivery system that achieves nine-sigma reliability through smart grid digital control and automation that anticipates and corrects disturbances before they occur.
- Smart infrastructure creation that automates the power distribution system and allows for instantaneous information and electricity exchanges between the smart grid and the supply market
- Smart user portal creation that allows price signals, decisions, communications and network intelligence to flow back and forth through the two-way energy-information portal.
- A seamless array of locally distributed power sources (including solar, wind, fuel cells, UPS and generators) that allows users to supply as well as purchase power. This capability also facilitates a smaller user’s carbon footprint.
Stage No. 2: Microgrid Implement
Galvin and Yeager believe the distinguishing characteristics of a microgrid include (see Figure 1):
- A community-scale power network consisting of interconnected loads and distributed energy resources that act as an integrated system, operating in parallel with the public utility grid or as an island;
- Integrated distributed energy resources that can provide sufficient and continuous energy to a significant portion of the internal load demand.
- Independent controls that can island with minimal or no service disruption.
Stage No. 3: Microgrid Master Controller Implementation
Aggregating and diagnosing every data point—let alone controling all of the devices generating the data within the microgrid—in such a vast system is a daunting software task. A software system called a master controller is at the heart of a market-aware microgrid enterprise that enables customer preferences for electricity use to be expressed and automatically implemented in a no-fail power system. A master controller:
- Provides the interface between the system controller and the individual loads, generators, energy storage and power conditioning equipment within the microgrid.
- Provides the local optimization function for the loads, generation, storage and power conditioners within the micro grid based on the economics of local vs. system conditions.
- Provides monitoring and control functions for real-time conditions (including risk assessment).
- Acts as the primary communication conduit between the microgrid components and the system controller to coordinate the microgrid resources with the power grid to improve system reliability.
- Provides an interface for microgrid users to review conditions within the microgrid
The microgrid and smart grid solution deployed at UCSD (see Figure 2) is extraordinary on several levels. It enables smart grid construction today—years ahead of when the experts predicted—and it employs technology already in use in related applications. (UCSD said it owns and operates a 45 MW peak load microgrid with multiple renewable and traditional energy generation resources, significant energy storage and a sophisticated monitoring for controlling flexible demand loads.)
While the terms power analytics and microgrids are relatively new, their concepts are extensions of proven, tried-and-true power methodologies that have existed for some time and have been proven in self-sustaining, microgrid-like environments such as enterprise data centers, where the most demanding power requirements imaginable are in play. The payback can vary from fast to immediate as one moves into more demanding applications. Capabilities such as reduced cost energy management, implementation time, downtime, alarm management and advanced monitoring lead to reduced power infrastructure management direct and indirect costs through unsurpassed power availability and reliability.
Kevin Meagher is chief technology officer responsible for product direction, business development and strategic planning for EDSA Micro.
Ken Wood is the business executive overseeing EDSA’s Paladin SmartGrid operations.
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