Implementing Smart Grid Solutions

In 2006, after a thorough audit of its existing communication capabilities, Great River Energy (GRE) sought to implement an efficient, modern, smart wireless communication infrastructure across its distribution grid. This initiative was aimed at better serving the growing demands on its generating resources, increasing operational efficiencies, and applying a communications infrastructure that would meet the long-term energy needs of both the energy user as well as the generation and transmission (G&T) members.

The communication infrastructure upgrade was a large and sensitive undertaking. As the nation’s fourth largest G&T cooperative with $1.7 billion in assets, GRE identified a great need to ensure a flexible, efficient and secure communication network. GRE has 28 member cooperatives in Minnesota and Wisconsin, distributing electricity to approximately 600,000 homes, businesses, and farms. Not only does GRE serve an extensive customer base, its network covers a vast geographical territory, fraught with significant environmental challenges.

Lots of real estate

The collective participants in the GRE family cover a total of 55,000 square mile, which contains 4,500 miles of transmission lines, 100 transmission substations and 475 distribution substations across rural areas in both states. This large territory frequently faces extreme weather conditions and is covered by rugged terrain. To service customers effectively while continuing to build a user base, the new communication network needed to be secure, efficient and real-time. GRE’s existing communication infrastructure was built several decades ago and relied on aging systems and proprietary networks that were difficult and costly to maintain.

In order to improve the resiliency and security of its dispersed field assets and respond more proactively to customer needs, GRE decided to implement a broadband wireless solution and modernize its infrastructure with smart grid capabilities. This meant that it would no longer have to deploy a new telecom network for each application. Instead, the company could migrate to a converged IP communication network, allowing for a gradual transfer.

Buy or build?

Traditionally, co-ops have had only two choices when automating their field operations and “virtualizing” field assets: either build their own custom private network or buy network services from a consumer-orientated carrier.

The pros of building your own include the ability to own and control the network, but this approach carries heavy technical and financial risk, including problems of using unlicensed spectrum or obtaining very expensive and limited licensed spectrum. The other option is to buy a service, with its own set of risks and rewards. The benefit is that a co-op can get up and running with a small monthly incremental fee per unit deployed; however they have to surrender control completely to the consumer-oriented carrier. Often this approach has many of the same problems: carriers simply do not provide services in remote and rural areas, nor can they eliminate the hodge-podge of networks required to span multiple carriers through home built systems.

Because the core of all smart grid solutions is a high-performance, secure, private, bi-directional communication system, GRE turned to Arcadian Networks (AN) to provide equipment and services for the project. AN set out to provide the best of both the build and buy scenarios.

AN provides custom, private, wireless broadband service for voice and data. It includes fixed and mobile communications designed to support energy companies, such as oil an gas companies and electric, gas, and water utilities. The company specializes in connecting rural areas that have mission-critical assets beyond the reach of other carriers, solving the last mile challenge.

700 MHz reliability

As a major holder of 700 MHz spectrum, covering over three-quarters of the continental U.S. and the Gulf of Mexico (and 220 MHz elsewhere), AN’s systems offer economies of scale which flow directly to its customers. Through its licensed spectrum, AN was able to provide GRE with a completely integrated wireless broadband network to accomplish SCADA (supervisory control and data acquisition) applications. In effect, GRE would be able to monitor and manage its dispersed generation and transmission assets over AN’s secure, private broadband network in real-time, ensuring reliable energy service throughout its customer network. Not only could this solution help prevent blackouts, it can serve to protect the long-term sustainability of the electric grid.

Other mission-critical applications facilitated by the wireless broadband network include:

Automated meter reading at point-of-delivery substations;

Voice over Internet protocol (VoIP);

Substation security surveillance;

Control area operations; and

Field workforce management.

AN’s 700 MHz broadband wireless system provides secure IP connectivity to any point on the system that GRE chooses to monitor and manage. Data transmission speeds of 1.2 Mbps upstream and 0.8 Mbps downstream ensure real-time availability of critical information. AN maintains a mission-critical network operations center with 24/7 staffing, to ensure constant supervision and strict adherence to North American Electric Reliability Corporation (NERC) and Federal Energy Regulatory Commission (FERC) guidelines.

Work nearly completed

When the project is fully implemented later this year, GRE will be able to monitor system performance instantly, gathering customer use and billing data at some 620 points on the system. Substations are equipped with WiFi hot spots so field crews can communicate wirelessly with operations when needed.

GRE and AN are working jointly to construct base stations and have been installing customer-premise equipment (CPE) manufactured by Vyyo. Base stations are broadband hubs that support IP data to and from the CPE. Each substation is outfitted with a 700-MHz wireless modem, router, firewall, and antenna. The system’s point-to-multipoint network design allows for communication up to 20 miles from a single base station—effectively giving multiple modems scattered over 1,250 square miles access to a single hub. Backhaul from tower sites to the GRE operations center is by fiber and digital microwave.

AN will own the base station equipment and spectrum, while GRE will monitor, manage and maintain the CPE and base station facilities under a separate contract. Fifty-two base stations have been installed, and installation work is underway on 15 more. By year-end, more than 95% of the base stations will be installed, covering the majority of the state of Minnesota.

Positive effects

GRE’s next-generation, mission-critical, last-mile substation automation project is transforming the cooperative into a more responsive, resilient, and real-time enterprise. Key to this transformation was augmenting internal skills with best-in-class carrier services to implement a secure, wireless communication platform that would deliver the highest option-value for the company.

Ultimately, GRE is better able to focus on its core competencies of delivering clean, reliable energy while leveraging AN’s competencies of delivering reliable and high-performance communication. With Arcadian’s network, electric utilities such as GRE, can shave their peak load or better manage the demand for electricity during peak periods. This has the power potentially to save millions of dollars and help to protect the future of the electric grid.

Author Information

Jake Rasweiler is vice president of engineering and network operations for Arcadian Networks. Reach him at jake.rasweiler@arcadiannetworks.com .

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