THE DISCUSSION HAS LONG BEEN BREWING: SHOULD OUR smart grid networks be public, private or a combination of both? Within utility projects and deployments, we've seen very clearly that one size doesn't fit all, no matter what the technology, software or system being implemented. Just as the smart grid is a network of networks, so, too, are the network needs within it.
But as the debate continues, the Utilities Telecom Council (UTC) opted to discuss the issues and dispel some myths in a February 2011 document titled "The Truth About Utility and Other Critical Infrastructure Industry Telecom Capabilities and Needs." "CIIs (critical infrastructure industries) will ultimately choose to build their own networks or buy telecom services based upon technical requirements, costs and levels of service required. CIIs have and will continue to utilize others to provide telecom services for certain aspects of their operations and smart grid deployments based upon these criteria," the UTC paper noted.
Subtle issues at play
Historically, the issues that have come up in the public/private network debate have centered around cyber security and standards issues. Public carriers point to the fact that they have already solved the very same issues utilities are now facing in both areas, and can offer both best practices and state-of-the-art technology.
But while utilities may be exploring public networks in certain areas, such as distribution, the areas of transmission and generation still tend toward private networks, for a number of reasons.
Regulatory structure also plays a part in utility network decisions. While in the United Kingdom, the regulatory structure really favors the public market, there is still a real incentive for utilities in the United States to own their own networks, taking the private approach.
Hydro One chooses mesh solution
As but one example, Hydro One Networks Inc. opted for the mesh network route for its communications. Owned by the province of Ontario and the province's largest electricity distributor with a service territory land mass twice the size of the state of Texas (123,000 kilometers of distribution lines and a 640,000 square kilometer service territory), Hydro One's customer base of 1.3 million is a mix of urban, rural and remote customers, some accessible only by air, rail, boat or snowmobile.
Based upon its unique needs, the distribution utility chose a two-way mesh radio network that would allow it the flexibility to accommodate cellular, broadband or fibre WAN back-haul capability.
More specifically, Hydro One's AMI solution architecture is comprised of a two-way self-healing mesh radio network based on the global 2.4 Ghz IEEE 802.15.4 standard. The solution provides the utility with the future-looking flexibility to accommodate cellular, broadband, or fibre WAN backhaul capability.
By integrating standards-based mesh radio and WiMAX wireless technology, the utility will be able to implement a broad spectrum of initiatives, including distribution automation, outage management, theft detection, remote disconnect, mobile work dispatch, two-way communication home thermostats and real-time energy monitors, and more.
Avista chooses broadband route
Others have gone the private route, as well. In Pullman, Wash., Avista Corp.'s smart grid demonstration project will incorporate an advanced metering infrastructure (AMI), smart grid communications and distribution automation devices using a private wireless broadband communication network. According to Jim Corder, Avista's director of IT infrastructure, the choice will allow the utility to bridge
the two network technologies while reducing the number of devices the utility has to manage and support. "We're expecting the network will meet or exceed all of our performance requirements for the initial smart grid applications," Corder said.
Texas co-ops opt for public communication with homes
On the other side of the coin, public networks are also being used by utilities to manage certain two-way communication aspects of the evolving grid.
According to a recent EPRI white paper, "Communication Modularity: A Practical Approach to Enabling Demand Response," an important part of the smart grid vision is "enabling communication-connectedness with residential devices so that they can be informed of grid conditions, including energy price, critical peaks and other curtailment events." Communication tointelligentdevices,thepaper'sauthors go on to say, rather than cutting power off with a remotely managed switch, "provides more flexibility for consumers and allows manufacturers to innovate, discovering creative ways to maximize energy savings while minimizing user inconvenience."
Texas-based Bluebonnet Electric Cooperative and Pedernales Electric Cooperative, in partnership with the Lower Colorado River Authority, piloted a public carrier solution using 3G and 4G LTE networks to provide real-time communication from their consumers' electric meters to a central data center, empowering Central Texas residential and small commercial members to actively monitor and control their energy usage through a smart home area network (HAN) installed within their homes or businesses.
Two-way communication is critical to enabling viable load management while still enabling consumers to maintain control of their energy use. Both co-ops were able to combine third-party demand response technology with a public carrier solution, leading to the potential for a broader-scale use. "Our tests on the technology during the winter load events showed the enormous potential of a load management program that benefits both consumers and utilities," Bluebonnet CEO Mark Rose said upon completion of the pilot project.
No either/or necessary?
Riding the wave of diverse needs, some vendors have opted for both public and private solutions for utility clients, depending upon specific yet diverse needs. With approximately 3,200 utilities across the country comes the potential of 3,200 individual needs. As standards continue to be set, these standards will allow utilities to make their own decisions based on their business cases and their individual needs.
In fact, many vendors and utilities alike are no longer seeing communications networks as an either/or solution. One major player explained it this way: "I believe it's a blended solution between private and public networks. Communications consists of a network of networks stretching across all seven domains. The bottom line? I believe there's a place for both technologies."
Utilities, he said, need to look at a variety of factors when deciding what solution is best, and for what uses. First, it's important to look at the actual use case. Add into the decision the cost of the particular application, the regulatory environment, latency and through-put, availability and reliability of the solution and cost and longevity, and the answer is complicated and utility-unique.
Some utilities have opted to use both public and wireless, with collection points served by both, using the private network as the primary network (especially with regard to the "last mile" to the meter), and the public network as the failsafe, or the backhaul network.
Capx issues play a role
Investor-owned utilities (IOUs) looking for rates of return might not opt for public network solutions in which the recurring expense of the public network passes through to the consumer. Large IOUs, in the current regulatory atmosphere, are motivated to be very conservative, based on their regulatory structure. As well, the historical culture of the electric utility industry has been one of "build it, own it, manage it."
Alternately, small utilities might find the public network solution to be the one that best fits their business cases. Running a network is complicated, especially with a minimal number of employees already stretched in other responsibilities.