The Smart Grid Primer: Building the Smart Grid Broadband Network

To operate a smart grid, rural utility providers will need last-mile broadband infrastructure connecting smart meters with remote locations and central offices. As utilities evolve and interconnect their networks, they will also need large-scale connectivity between their aggregation points.

Utilities looking to develop a smart grid have several options. They can build their own last-mile and core broadband network, partner with an existing network operator to provide the infrastructure or meet somewhere in the middle, deploying last-mile connectivity while working with a backhaul aggregator. The decision is based upon a variety of factors including the utility’s unique needs and the local regulatory environment as defined by each state public utility commission.

Private versus Public Networks

Traditionally, electric providers have built private networks designed for crew communications and to control substations. Utility providers have justified this expenditure with the need to ensure service continuity at all times, especially during emergency scenarios.

Utilities are not only accustomed to operating private networks, they also have economic disincentives to use commercial networks. The utility industry is regulated at the state level. As rate-of-return regulated utilities, they typically earn guaranteed profits on the assets they deploy—such as private communications networks—but only receive cost recovery if they use commercial networks. In an attempt to eliminate barriers, The National Broadband Plan (NBP) released in March 2010 requested that state regulators carefully evaluate the current regulatory structure to reduce impediments and financial disincentives to using commercial networks for smart grid communications.

Electric providers maintain that private networks offer them control and simplicity of operations. “Utility providers want to utilize one ubiquitous broadband network for all of their customers, but in rural areas, not all of the customers are serviced via one [broadband] network,” said Vern Dosch, CEO of the National Information Solutions Cooperative (NISC). “This creates complications for utilities.”

Electric providers service much larger geographic areas when compared with rural telcos, and their territories are often served by Bell companies. In order to partner with local broadband providers, rural electrics will need to negotiate with various local telcos and Bell companies, as well as middle-mile providers for transport.

Despite utilities’ historical preference to operate private networks, Dosch noted that the complexity and expense of managing and operating a private broadband network should not be underestimated.

Commercial networks are often suitable for many smart grid applications including metering and routine sensing applications. They also may provide a resilient and reliable network at an equal or lower total cost of ownership. The cost to build and maintain the network is an important attribute to the utility provider and its state regulatory authority.

Network Topology

The underlying smart grid broadband infrastructure, both within the home and within the larger grid, may utilize wired, wireless, cellular or mesh topology. “There is no one-size-fits-all solution,” said Ed Drew, National Rural Telecommunications Cooperative (NRTC) vice president of utility solutions. “Every utility is different, and you really need to consider the geography of a utility’s territory in order to make that decision.”

Drew also reminds us that rural areas have unique electric—and smart grid—needs. “When selecting a telecommunications solution, a utility also needs to consider connectivity to areas where there are no people at all. For example, many rural areas will require connectivity at applications like irrigation pumps so the utility can remotely turn them on and off to reduce energy demand.”

Utility providers often are turning to wireless technology for collecting smart meter data from homes and businesses. “Rural electrics are switching to a wireless broadband because of the relative cost, bandwidth and reliability,” said Bob Saint, principal engineer at the National Rural Electric Cooperative Association (NRECA).

The electric industry has requested licensed spectrum from the FCC in order to operate a private IP network to exchange smart meter data and emergency voice communications for utility employees. The NBP proposed that utilities share or lease space on the public safety 700 MHz wireless broadband network, an idea which the Utilities Telecom Council (UTC) supports. The UTC also has asked the FCC for an additional 30 MHz of spectrum in the 1800-1830 MHz spectrum band to be set aside for smart grid applications, auction-free or without cost. The utility providers suggest that this set-aside will match with Canada’s bandwidth allocation, creating a larger, attractive market which might invite more equipment manufacturers.

Bandwidth Needs

The million dollar question: How much bandwidth is necessary for smart grid operations? Experts at NISC, NRECA and NRTC characterize a smart grid broadband network as carrying bursts of data at even intervals. “Most smart meters in use today are capable of sending data at 15-minute increments, which is in excess of 2,900 meter readings per month,” Dosh said. “The telco’s wired broadband network—DSL or FTTH—will not notice this dribble of bits and bytes compared to other bandwidth-intensive Internet and video needs.”

Drew added that historically, bandwidth needs have been modest. “Smart meters collect and transmit relatively small amounts of data, about 300 kilobits with every reading; however, the frequency of reading is increasing, and that data is being brought back to substations, aggregated and sent on to the utilities’ operation centers.”

Last-mile connectivity is just part of the picture. Drew notes that utilities will need high-speed connectivity, often microwave or fiber links, between their substations. In addition, utilities may require mobile voice, data and video surveillance in the field, and high-speed data and voice access in their operations centers. “Bandwidth demands will grow but, bandwidth may not be as challenging as the need to reach 100% of the service area, ensure low latency and provide four- or five-nines network reliability,” Drew said.

Utilities Partner with Telcos

In the quest to build a smart grid broadband network, rural electric and rural broadband providers can partner together to leverage each other’s strengths and share resources. “Redundant systems are expensive,” Saint said. “It’s imperative that rural electric and rural telco providers work together for the good of our members and our customers.”

Rural telcos are equipped with the network capacity and technical expertise needed to build out the network. Dosch advises telcos to be progressive and assertive. “Don’t sit and wait,” he said. “Knock on your local electric provider’s door and ask if there is any way your telco can help—if you can collaborate to leverage the existing infrastructure the telco has in place and its technical expertise. You will provide a valuable service to the local utility provider and perhaps create a new revenue stream in the process.”

Telcos will need to understand utility providers’ unique needs before engaging in partnerships. Reliability, resiliency, low latency and security are fundamental to their operations.

Drew also advises telcos to talk with management at local electric utilities: “What are their communications needs? Are they installing smart meters, upgrading substations, adding mobile data to their work fleet or more? What communications technologies do they use today? Are they looking at building out communications systems? Can you provide what they need, or work together on shared resources or joint build-outs? Can the local electric co-op be an anchor tenant for your network?”

The collaboration between broadband service providers and utility operators is an evolving process that will take different forms in various communities nationwide.

Stay tuned for part four in our series which will explore smart grid standards, the foundation of an intelligent network.

Related posts:

1. The Smart Grid Primer: The Evolving Architecture of a Rural Electric Provider
2. The Smart Grid Primer: Standards Development
3. The Smart Grid Primer: Resources
4. The Smart Grid Primer: What is the Smart Grid
5. Telco/Utility Partner for Rural Indiana Smart Grid Network