Smart Grid Communications

The utility industry has reached a consensus: It is time to replace vintage grid infrastructure. What remains unclear is which communications platform or platforms will support the widespread upgrade.

The injection of large amounts of stimulus funding into the industry has created a gold-rush frenzy among suppliers entering the electric utility marketplace with communications products, some of which are not specifically designed for utility applications. The unique sensitivities of utility operations, the complex regulatory environment and the much slower pace of technology implementation create a complex formula by which utilities must choose the right smart grid communications platform.

“This basic foundation of communication provides the platform for innovation,” said Steve Hauser, vice president of grid integration at the National Renewable Energy Laboratory (NREL). NREL is building a US$175 million lab, slated to come on-line in 2012, that will do network simulations for distributed generation and other smart grid applications. NREL is also the data repository for all the Recovery Act smart grid projects.

“The big benefits of smart grid lie in the applications that change the way we deliver electricity,” continued Hauser. “We are talking about massive network storage, massive network distributed generation and massive network demand management.”

As utilities delve into the subject, trying to determine the best network for their specific smart grid needs, the search tends to raise more questions than revealing clear-cut answers.

Short Technology Cycles and System Obsolescence

The advent of the smart grid represents the merging of two industries — information technology (IT) and the power industry. The pace of each industry in terms of implementing innovation and change tends to be polar opposite. This represents a major issue surrounding what communications platforms a utility might choose in its plans.

“The problem is that utilities have operated in an environment where grid-related equipment such as remote terminal units (RTUs) and intelligent electronics devices (IEDs) are replaced every 15 to 30 years,” said Doug McGinnis, principal smart grid communications architect at Exelon Corp., parent company of PECO Energy and Commonwealth Edison. McGinnis is also past chairman of the UTC Smart Networks Council. “In IT, we look at technology refresh on a five-year time horizon. Getting the utility to think this way is a real culture shift.”

McGinnis also noted that much of the smart grid technology is in its infancy, so making decisions at this point is challenging, particularly in regard to the evolution of standards by the National Institute of Standards and Technology (NIST). NIST is currently developing interoperability standards for all smart grid-related equipment. The organization published an initial framework and roadmap for smart grid standards in January 2010, with an updated framework slated for presentation in early 2011.

“The effort to develop interoperability standards has forced a lot of thinking in the industry, because you can't definitively decide on standards until you've decided on architecture,” Hauser said.

“One area of debate is the Apple versus Microsoft platform,” Hauser said. “Both companies, plus Google and Cisco, are interested in the market, but Apple has very closed, proprietary systems. All of Apple's applications have to be specifically approved by their developers, but it hasn't constrained innovation in terms of the applications for the Apple platform. The Microsoft system is more open, but much more prone to problems. There is an on-going debate about how open is open: proprietary open or non-proprietary open. If you want to protect privacy and you want interoperability that works all the time, then what does that mean for the architecture you choose for your platform?

“NIST is evaluating all the interoperability standards options, such as federally mandated standards, voluntary standards and those developed by the Institute of Electronics and Electrical Engineers (IEEE),” Hauser said. “IEEE standards could take 10 years to develop and implement, but we can't wait that long. Utility decision-making cycles that take years are being mixed in with technology cycles that take months.”

Security is a key element of the smart grid framework, said McGinnis. “Security must be built into the architecture from the ground up. It's not something you overlay on top. NIST is developing suggestions for various controls that should be applied to smart grid, such as using FIPS 140-2 compliance cryptology modules. We want to keep our technologies aligned with evolving NIST interoperability guidelines.”

Bruce Hamer, smart grid program manager at Burbank Water and Power, said the changes in advanced metering show how quickly new technology becomes outdated. “Look at AMI (advanced metering infrastructure) versus AMR (automated meter reading). You have one-way communications to read meters, and before that took off, two-way communications caught on,” Hamer said.

Narasimha Chari, Tropos co-founder and chief technology officer, offered these insights in an August 2010 article published by GigaOM, a provider of online media and research for technology companies.

“Since communications technology evolves at a faster rate (two to four years) than utility capital investment cycles (15 to 20 years or more), equipment vendors and service providers must make long-term commitments to supporting deployed networks,” Chari wrote. “For many utilities, a commonly expressed concern is that they are ‘forced’ by the faster phone company technology upgrades into upgrading large numbers of deployed meters and field devices or deal with the consequences of technology that is no longer compatible.”

Mark Madden, Alcatel-Lucent's vice president of energy markets for the Americas, said utilities are fearful of investing in a network with a less than 10-year depreciation cycle.

“We are in the innovation stage of smart grid, and there are technologies going out now that may not be useful five years from now because of uncertainty concerning the regulatory hurdles,” Madden said. “While my company is technology agnostic, and I personally believe we are the largest integrator of utility WiMAX networks today, we believe that WiMAX has a limited lifetime and we are currently working to make LTE (the next-generation 3G and 4G technologies for both GSM and CDMA cellular carriers) available and relevant to the utility market.

“WiMAX was quicker to the market, and the second-to-the-market LTE is more robust, but the ecosystem is just not ready yet,” Madden said. “I was talking to an investor-owned utility executive who was bemoaning that he had lifespan concerns regarding deploying WiMAX and that LTE is so close, but that he had stimulus money that he must spend before the new technology is available to him. Nearly all of the carriers have said they are going to put out LTE. There are just not enough network operators putting out WiMAX on a global scale, which is why we believe that WiMAX will be around awhile longer but will eventually fade.”

The utilities that received stimulus money are in a difficult situation, Madden said, because they must act now to spend the funds, but technology continues to develop and change. He used Google's Power Meter technology and radio-frequency mesh networks as an example. Google is promoting real-time, on-demand access to a meter, but if information is being sent to and from a meter in near real time, there is not enough bandwidth on the current mesh networks to support this activity.

Mesh networks are, in large part, proprietary technologies being provided by new startup companies. There is concern these small providers will go out of business, leaving the assets stranded, Madden said.

The best approach is for the utility to plan for capacity and performance based on forecasted needs for the next 10 years, according to Charles Hill, Black & Veatch regional general manager. “At the same time, you need to build upon established technology standards and trends when possible, while also trying to leave the door open for emerging technologies,” said Hill.

Multiple Networks

Burns & McDonnell has advised numerous utility clients on potential communications platforms to support their smart grid projects. Their general advice is that the typical large utility may need three different platforms, according to Matt Olson, senior electrical engineer of telecommunications and network engineering at Burns & McDonnell.

“Most larger utilities have a mix of customers in rural, suburban and dense urban settings,” Olson said. “They are going to need multiple technologies to provide communication throughout their service territory. Many utilities use wideband or mesh wireless technology to augment their private fiber or microwave network in urban and suburban settings and narrowband, high-power, high-penetration technologies to reach out into rural or fringe suburban areas. The last coverage challenge is the underground networks in city centers. Broadcast wireless technologies don't propagate into manholes. In these areas, store and forward mesh wireless such as ZigBee or power line carrier are options.”

Burbank Water and Power's multitiered approach for its network may become the standard for many utilities. The foundation is the city's extensive fiber connecting its 20 electric substations. The city will connect that fiber to a second-tier Tropos wireless network.

“We chose the Wi-Fi technology because of its speed and the low latency, as well as the redundancy you get from a mesh network,” said Hamer. “That Tropos wireless network will give us connectivity to all of our field devices as well as interface with the AMI metering communications. The next tier is a Trilliant AMI system that creates a mesh network with radios in all the electric meters. That collects back to Trilliant collector radios that we backhaul through the Tropos Wi-Fi and back through the fiber. It is a system that is robust, secure and can easily be expanded to future applications.”

Hamer said that his utility determined cellular would be too costly because it is owned by a third party, and it would not have the low latency or throughput the utility needed.

“Some utilities are just looking for advanced metering infrastructure communication, but that won't give you the performance you need for distribution automation, and it is unclear what type of performance it would give for demand response,” Hamer said. “The big issue is distribution automation where you are automating your feeders and you want to be able to restore a trip within milliseconds. You aren't going to get that with an AMI system.

“With our multitier approach, we are able to leverage our earlier investment in fiber optics, but sometimes utilities don't have that so a cellular solution would be convenient,” Hamer said. “Cellular is not likely to give you the speed or the control required for grid operations because you would be working with a shared wireless network managed by AT&T, Verizon or another large carrier.”

The Private Versus Public Debate

Industry insiders have debated the merits of private versus public networks. SmartSynch's Chief Marketing Officer Campbell McCool's bold declaration that utilities have no business operating private communications networks represents one extreme, while most voices have gravitated toward more of a combination of public and private networks.

Texas-New Mexico Power (TNMP) has a pilot project underway with SmartSynch that is using 13,000 meters for AMI on a public network.

“We lean to public wireless because our utility is small and we don't want to invest in infrastructure that we can't support. We'd rather let the carriers do that,” said Gary Kessler, TNMP's enterprise architect for smart grid. “If we go with a public carrier, our operation and maintenance costs are going to be the same as if we hire meter readers. We could keep the capital and invest it in transmission projects in which we would get a better rate of return. Also, it can be difficult to get AMI projects approved by regulatory commissions.”

Kessler said that even though he is generally a proponent of public networks, his utility uses private networks for more critical functions.

“Both PECO Energy and Commonwealth Edison have significant smart grid plans underway,” said McGinnis. “Both utilities are centered on private networks, mainly because the public carriers' performance has been less than stellar on both the wired and wireless sides. Their legacy analog equipment is unreliable and is down for extended periods, and skill sets to maintain the technology are becoming limited. This is frustrating for a utility, particularly in the SCADA [supervisory control and data acquisition] environment.

“The newer communications are more reliable, but not reliable enough for some utility applications,” McGinnis said. “For instance, teleprotection, or relay protection — the communication between the relays and the transformer in the substation and the high-voltage lines — is critical and must be available. When these circuits go down, we have to take a transmission line out of service and that can have a substantial impact on the grid. Public telecoms just have not demonstrated their ability to provide the required level of reliability.”

Hill said that whether a utility chooses a private or public network depends on the specific requirements of the utility application.

“For mission-critical applications, most utilities continue to rely on their private networks because of their historic reliability under all conditions, including the Northeast blackout of 2003, Hurricane Katrina, and other long-term outage events when public networks proved unusable,” Hill said. “For other utility applications such as meter reading, utilities are willing to consider alternatives when they can provide significant cost or other value and benefits.”

While most utility network communication needs will be fulfilled by private networks, public cellular networks can still play an important role in augmenting private networks, according to Chari.

Focusing specifically on wireless, Chari examined the key issues of communications for utilities:

• Availability

  Public carriers can have high degrees of network availability, but the services they provide are shared with the consumer market so network performance can degrade dramatically in network congestion.

• Survivability

  Public carrier networks have a mixed record with survivability, the system's resilience in adverse conditions. For example, in its filing with the Federal Communications Commission (FCC), Southern Company noted that it had to rely on its private communications networks to aid in power restoration after an extended weather-related outage, as the public network was out of service during that time. A lack of adequate backup power on commercial networks results in the public network remaining unavailable until electric service has first been restored.

• Coverage

  Utility private networks often use a combination of wireless technologies to achieve their coverage goals. Commercial public carriers' business models and systems are optimized around providing coverage to the largest number of consumers possible, versus being designed to ubiquitously cover an entire utility service territory. Unserved or underserved areas are not economically feasible for a public carrier.

• Latency

  Some mission-critical applications, such as distribution automation and wide area monitoring, require very low latency (how long it takes the data to run over the network). Compared to private wireless technologies that reach latencies in the 10-msec to 100-msec range, public cellular technologies widely deployed today offer latencies in the 100-msec to 1,000-msec range.

• Security

  Information security capabilities and protections exist in both well-designed public and private wireless networks, but an additional aspect of security in the context of utility operations is the need to ensure system integrity and availability even under adverse conditions such as external attacks or disruptions and peak loads.

• Control

  One benefit of a privately owned network is the ability to design and implement a network that meets the reliability and security needs of mission-critical smart grid applications, while making any necessary cost or technology tradeoffs along the way. By contrast, public carrier networks are designed to the cellular operator's business objectives, which may not be aligned to those of the utility.

Bob Gustin, Sprint Nextel's industry solutions manager for the utility sector, said his company believes in a flexible architecture that is a hybrid of technologies to support a fully integrated smart grid.

Obtaining Spectrum for Private Networks

“Cellular networks, with their broad coverage and billions of dollars in investments, have resulted in a large-footprint broadband capability to support a lot of smart grid applications,” Gustin said. “However, we are also clear that mission-critical applications should primarily remain with a private utility network. There is certainly a strong place for cellular networks, not in generation or transmission, but in distribution applications such as nodal points, routers and endpoint devices. With cellular technology, the bandwidth requirements are there.”

Gustin noted that, in developing a partnership between telecom providers and utilities, coverage and network reliability are critical issues.

“The expectations of utilities have taken telecom providers to a much higher level in terms of service agreements,” said Gustin. “Another consideration is that a carrier can provide a very large footprint that can be used for both smart grid and enterprise mobility for the utility.”

Verizon's Rilck Noel, vice president and global managing director of energy and utilities practice, echoed the same sentiments expressed by Gustin.

“Verizon believes in a collaborative hybrid approach in which utilities and telcos work together,” Noel said. “Verizon can help design, build, enable end-to-end security and operate such hybrid networks. Both utilities and the telcos have great things to bring to the table, so it is a matter of working with each utility to find where we can combine our strengths. Moving to the smart grid can be made in simple steps, and our wireless and wired communications, IT and security solutions are perfect building blocks for the energy industry's transformation.”

Utilities that have determined a private network should have a place in their communications mix still face the hurdle of acquiring spectrum for the network. This is probably the most challenging issue in building PECO Energy's and Commonwealth Edison's communications platforms, according to McGinnis.

“There is no one best solution,” McGinnis said. “It is really the lesser of the evils — which solution will give you the fewest concerns. The concerns are not just the costs but also the requirements to provide certain levels of coverage across the territory. For unlicensed spectrum, there are the issues of noise and interference, and the fact that the equipment could be rendered useless at some point due to an increasing and uncontrolled noise floor.”

Municipalities and Coops Versus IOUs

Olson from Burns & McDonnell agreed. “There are no technologies or vendors that are universally being deployed. It all depends on the spectrum a utility is planning to use. ”

Olson outlined some of the other challenges of acquiring spectrum:

• The FCC has not allocated a band for smart grid communications, so unlicensed bands must be used or spectrum must be purchased during an FCC auction or from an auction winner. The auction process is not conducive for utilities because they occur infrequently, often requiring a large purchase sometimes years before the application or technology is proven. Lastly, the utility is competing against speculators or other companies who are trying to secure rights to a scarce resource.

• Licensing spectrum from a license holder is a good option, but it can be hard to find a band where the spectrum is available across the entire service territory and where the owners are willing to lease their spectrum, which can be for specific frequencies, areas and times. Just locating the owner or their agent can be a challenge because of the nature for license holders to be special-purpose entities whose controlling owner may have changed multiple times. This is exacerbated if a utility has a large service territory requiring them to work with multiple owners. Lastly, if the license is not desegregated, it can be difficult to make the utility the direct license holder in order to secure lease terms that protect the utility's interests if the license holders becoming insolvent.

In an August 2010 proposal filed with the U.S. Department of Energy, the Utilities Telecom Council (UTC) suggested that utilities could access spectrum on a shared basis with federal government users or public safety entities.

“They use communications in similar ways,” said William Moroney, UTC president. “They each need reliable networks especially after natural or manmade disasters to support the delivery of essential services to the public. In addition, they need interoperable communications to respond to emergencies effectively. Moreover, shared networks will make more efficient use of resources such as towers as well as spectrum.”

In choosing a communications platform for smart grid projects, the public power sector has more flexibility in trying new technology, according to Tom Pitstick, vice president of Cooper Power Systems' Energy Automation Solutions group.

“The decision-making process is more local,” Pitstick said. “They aren't worried about a rate case. They are just trying to find cost-effective solutions to improve electricity delivery for their customers. The economic decision-making processes are different for munis, coops and IOUs.”

Glendale Water & Power chose Wi-Fi primarily because the platform could easily serve both the public power utility and other city departments.

The Evolution of Smart Grid

“The Wi-Fi mesh network we chose is easily expandable,” said Craig Kuennen, business transformation and marketing administrator/smart grid project sponsor at Glendale Water & Power. “Initially, we installed it just for our AMI, but as we go forward with smart grid, we could add radios to the network to make it faster. You can easily add more bandwidth to meet your latency requirements.”

The Nebraska Public Power District (NPPD) is a wholesale provider of public power to numerous entities in the only state in the union that is 100% public power.

“Our larger challenge than the technology solution we choose is how we will deploy just one system for the state,” said Dave Webb, NPPD's information and telecommunications technology manger. “We need to find a way to share the communications platform with our wholesale customers and share the cost with them.”

Webb said the issue is complicated because NPPD serves more than 100 entities in the state. The wholesale provider will focus its efforts on finding a solution for its largest customers and all the municipalities. To complicate matters, some of the small towns have their own generation facilities. NPPD works with the regional power districts and, if they deploy smart grid communications networks, Webb said that NPPD may find a way to benefit from those networks.

NPPD has its own fiber and microwave facilities that will be part of its smart grid solution. The district is looking at WiMAX, most likely as a private network, but remains open to solutions such as Motorola for backhaul and mesh networking like that offered by Silver Springs.

NPPD's Land Mobile Radio system, constructed in partnership with the state of Nebraska, provided very little data capability. However, the partnership itself and the network connectivity associated with the system, lays the foundation for a broadband network partnership that could contribute to a cost-effective smart grid solution.

How will smart grid evolve over the next five years? Right now, many states are waiting to see the results of smart grid pilot projects before jumping into their own projects, according to Brett Kilbourne, UTC's director of regulatory services and associate counsel.

“There has been a lot of focus thus far on smart meters, but the real sweet spots for utilities in smart grid are the grid functions in terms of reliability and performance,” said Kilbourne. “That is where the most benefits of smart grid will be realized.”

Madden agreed. “The best return for distribution utilities on smart grid is in distribution automation and substation automation,” Madden said. “This allows utilities to defer investments in the grid while allowing them to optimize their assets and improve reliability. They can predict failures before they occur; they can shift electric delivery around so they are taking advantage of smaller margins on the lines, which allows them to avoid, or at least delay, putting in expensive new feeders and generation. Those are the areas where I think we will see more activity now that the stimulus funding is set and the hype is cooling down.”

Hamer predicts that five years from now, most utilities will have AMI systems and smart metering to enable time-of-use rates. Renewable energy use will also become widespread.

“We are embarking on a journey to help consumers use power wisely,” Hamer said. “For example, 10 years ago I had one trash can, and today I have three trash cans, but 80% of my waste is recycled. We changed the culture around managing waste. We need to apply that same dynamic to the way customers use energy.”

Cathy Swirbul is a freelance writer

Utility Communications Technologies, Tiers, Bandwidth and Latency Ranges

Communications technology	Utility communications tier Backbone (1) Backhaul (2) Field applications (3) Premises metering/ Load control (4)	Technology bandwidth ranges (per second basis)	Latency ranges (milliseconds)
Wireline technologies
Fiber	1,2	1 Gb to 100 Gb	<2 ms to 10 ms
DSL/ADSL	1,2	256 Kb to 24 Mb++	<20 ms to 50 ms
Dial-up	1,2,3,4	28.8 Kb to 56 Kb	>20 ms
BPL	2,3,4	256 Kb to 135 Mb	10 ms to 75 ms
Ripple/DLC	3,4	56 Kb to 1 Mb	>20 ms
Wireless-1 technologies	Urban 2,3,4 Rural 1,2,3,4
Satellite	2,3	1 Mb to 40 Mb (shared)	>250 ms
Microwave	1,2,3	10 Mb to 10 Gb	<5 ms
Licensed-spectrum radio	1,2,3,4	10 Mb to >1 Gb	<15 ms
Wireless-2 technologies	Urban 3,4 Rural 2,3,4
2G and 3G cellular	3,4	200 Kb to 1 Mb	>15 ms
4G cellular	3,4	100 Mb to 1 Gb+	5 ms to 15 ms
Mesh (Wi-Fi) (multiradio)	3,4	<5 Mb	>25 ms
Source: Newton-Evans Research Co.