U.S.A (3): Borrego Springs Microgrid Demonstration

Project Background

Microgrids have been demonstrated successfully for single customers but have not been designed and demonstrated across multiple customers as a utility asset. For utilities to adopt microgrids as an operating option, a utility microgrid needs to be designed and demonstrated to establish utility operational practices and show the benefits for multiple utility customers. The Microgrid Demonstration focused on the design, installation, and operation of a community scale “proof-of-concept” Microgrid demonstration. The site of the Microgrid was an existing utility circuit that had a peak load of 4.6 MW serving 615 customers in a remote area of the service territory.

The key aspects of the Microgrid Demonstration were the integration and operation of the following types of equipment and systems:

• Distributed Generation
• Advanced Energy Storage
• Price-Driven Load Management
• Fault Location, Isolation, Switching and Restoration
• Integration with DMS/OMS and Microgrid Controls

The overall objectives for the Microgrid Demonstration were to:

1. Demonstrate the ability to achieve a 15% or greater reduction in feeder peak load
2. Develop a strategy and demonstrate the integration of the Automated Metering Infrastructure (Smart Meters) system into Microgrid operations
3. Develop a strategy and demonstrate ‘self-healing’ networks through the integration of Feeder Automation System Technologies (FAST) into Microgrid operations
4. Develop a strategy and demonstrate the integration of an Outage Management system/Distribution Management System (OMS/DMS) into Microgrid operations
5. Demonstrate the capability to use automated distribution control to intentionally island customers in response to system problems
6. Develop information/tools addressing the impact of multiple DER technologies

The scope of the project was conducted in two phases. The first phase established the design and demonstration plan for addressing four fundamental and interrelated goals:

• Integrating utility and customer based energy resources
• Enhance management of customer resources
• Identify and evaluate key technical and operational aspects of design, implementation and management of an integrated energy portfolio of utility and non-utility interconnected resources
• Improve power reliability and quality through utility asset management

The second phase applied the lessons learned in Phase 1 to implement the solution. The key elements of the Microgrid resources implemented for the project were:

• Two 1,800 kW Diesel Generators
• One 500 kW / 1,500 kWh lithium ion energy storage unit
• A Fault Location, Isolation and Service Restoration system
• A Microgrid Visualizer to support control and monitoring of the Microgrid resources
• An automated demand response system with pricing based event capabilities

Approximately 60 residential and small commercial customers were provided home-area-network energy management systems to display real-time energy use and pricing information and provided education and training to use the convenient options to manage energy use remotely. These customers were provided incentives for participating and actively managing their energy usage to moderate heavy electrical use during peak demand periods to prevent electrical supply emergencies during the operation of the Microgrid.

One of the highlights of the Microgrid Demonstration was the ability to effectively island the entire Microgrid supporting more than 600 customers. The islanding demonstration transition into and out of the island mode without affecting the quality of service to the customers (seamless transitions without an outage or flicker).The Microgrid on-site generation was able to deliver power to a large portion of the local grid during a planned outage, reducing the scale of the outage and the corresponding impact to customers. This demonstrates in a tangible way the great possibilities that exist when we use technology and customer engagement and participation to overcome operational challenges on the ground.

Case Description

Using Smart Grid and Smart Meters as the foundation, San Diego Gas and Electric (SDG&E) is developing innovative demonstrations that create an individualized, two-way relationship between the utility and the customer, engaging customers in active participation for improving grid operations and empowering them with information about energy usage and new opportunities to conserve electricity and receive value for it. This customer-centric approach is now a part of the utility’s ‘Connected’ brand, which emphasizes its connection to customers.

In cooperation with the US Department of Energy and the California Energy Commission, SDG&E along with multiple public and private sector partners developed the Borrego Springs Microgrid Demonstration Project. Microgrids have the potential to provide multiple benefits to customers including enhanced reliability, promoting renewable energy integration and encouraging customer involvement. This project studied how to best respond to a system disturbance and maintain power to a local area, allowing customers to potentially “ride through” the disturbance by having enough local generation and local energy storage and utilizing customer participation to meet the critical energy demands of the area. Microgrids have the potential to be an alternative service delivery model for some of those hard to reach customers or potentially those requiring higher degrees of reliability. They potentially have broad applicability and scale across utility service territories and terrains.

This demonstration project brings customer systems and utility circuit system realities together. While a few microgrid trials have taken place in the US, they have typically been of a smaller scale and not directly applicable to the real operating environment.

Figure 38. Borrego Springs Microgrid Demonstration Project

Project Outcomes

This project designed and demonstrated a utility operated microgrid that incorporates sophisticated sensors, communications, and controls to explore microgrid islanding (temporarily disconnecting from the grid) of multiple customers along an entire distribution feeder. The Borrego Springs Microgrid Demonstration successfully incorporated customer participation into the operations of the electrical delivery system by enabling coordinated demand response concurrent with Microgrid operations. In addition, the Microgrid integrated and controlled multiple distributed generation and electrical energy storage devices to operate the grid in the most cost-effective and reliable manner, benefiting customers by reducing overall outage time during very adverse conditions. Overall, the Borrego Springs microgrid achieved a greater than 15 percent reduction in feeder peak load and improved system reliability.

As one of the world’s largest and most complex microgrids, this installation experienced a real-life test demonstrating its reliability when thunderstorms and flash floods knocked down transmission and distribution power lines, creating an outage affecting 2,700 customers. The microgrid was able to island and provide power to more than 1,056 of the affected customers for over 20 hours.

In September 2013, the San Diego Union Tribune, a local newspaper in San Diego, California, highlighted the importance of the Microgrid Demonstration as “a first of its kind in the area…a more robust, resilient grid that can dynamically react to the changing environmental and system conditions… giving SDG&E and its customers a glimpse of a possible “utility of the future – one in which the grid itself can respond to outages by routing and restoring power where it is most needed, bringing vitally needed energy to residents and quite possibly saving lives in the process.” Such a grid protected those in need during outages by supplying energy where there would otherwise be blackouts. A coordinated automated switching plan for restoring power to critical public accessible areas like the Community Library (designated a ‘cool zone’), the local high school (a primary evacuation site), the fire station and sheriff’s station, and the Borrego Springs Airport, gave the community the flexibility to adapt to the 100 plus degree weather, and aid to those with critical life support systems. A copy of that report can be found on the following url:

http://www.utsandiego.com/sponsored/2013/nov/10/sgde-repair-crews-storm/

This effort allowed those customers directly benefiting from a Microgrid to be engaged and empowered through awareness and education on how their actions support a “self-healing” dynamic grid through community involvement.