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2019 Strategic Directions:Smart Utilities Report

Private Wireless Networks: Catalysts for Grid Modernization

The electric grid is undergoing the most significant transformation in its history, with digital technologies and devices being pushed to the edge to support dynamic, two-way power requirements in real-time while also ensuring reliability, efficiency and security.

As these digital devices approach the edge and are densified across the grid by more than 1,500 percent, utilities need an advanced wireless network that goes beyond supporting AMI and supervisory control and data acquisition (SCADA) devices that traditional Field Area Networks (FANs) support today.

A majority of respondents to this survey say the existing field are networks they're using for AMI and SCADA will need significant enhancements to support the digital utility of tomorrow.

Now the question is: What's the right technology solution?

That's the key reason nearly 63 percent of industry respondents to the survey for Black & Veatch's 2019 Strategic Directions: Smart Utilities Report say the existing wireless networks they're using for AMI will need upgrades in the foreseeable future.

Specifically, roughly 37 percent of respondents say the networks they have in place support current needs, and nearly one in four respondents say their networks somewhat support current needs. Only 2 percent said their existing networks do not support current or future needs, and all of these respondents see the need for changes ahead.

What are they looking for? Most are seeking a private wireless solution for their FAN. In fact, some 43 percent of respondents strongly prefer the private option, and 50 percent considered public versus private to be the most important criteria for evaluating a FAN.

 

Bring Your Own Band

Utility systems rank at mission critical, and maintaining reliability and security of these critical assets is vital. This explains why the Utilities Technology Council (UTC) asked the Federal Energy Regulatory Commission to go beyond its own jurisdiction and work with the Federal Communications Commission on securing spectrum for utilities to use. 

"For the most part, utilities have built out and maintained their own ICT networks, rather than outsourcing service from commercial telecommunications carries." Joy Ditto, UTC's president and CEO, wrote in a May 2018 filing."Utilities require high levels of reliability that traditional telecommunications carriers are unable or unwilling to provide."

Along with private networks, survey respondents showed interest in LTW — long-term evolution — networks. This is the current model for wireless cellular service and the foundation for next-generation 5G.

Among LTE's core specifications, you'll find downstream transmission rates up to 100 megabits per second (Mbps), upstream rates of 50 Mbps and radio access network round-trip times in the range of 10 milliseconds — speeds required for real-time data access that utilities will require to actively and autonomously manage two-way power delivery. 

LTE also uses an IP-based architecture and supports a protocol that prioritizes traffic, allowing utilities to share a pipe among various devices and enable dynamic traffic engineering on the basis of latency requirements. In other words, one network supports many applications. Pushing LTE and IP to the edge will be necessary for utilities' 4G and 5G modernization. Laying the foundation for 5G now better prepares utilities for distribution modernization over the long term. With promises of hyperspeed, low-latency and edge computing capability, utilities' vision of efficient, autonomous and customer-centric systems is closer to reality. 

The Need for Speed

Nearly 84 percent of survey respondents said they were modernizing to "increase monitoring, control and automation capabilities," while 82 percent wanted to "improve the reliability of the grid." Two-thirds of respondents targeted improvements in "operational efficiency and volt/VAR management."

One way utilities are increasing monitoring is to deploy sensors throughout the distribution grid, including distribution-level phasor measurement units (PMUs), which have been used in transmission systems for several years. 

Some distribution system PMUs take readings as often as every one to two cycles, which equals 30 to 60 readings per second in a 60-hertz system such as the North American grid. The units can measure voltage, current, phase characteristics, frequency and its rate of change, switch status and more. They also have a Global Positioning System (GPS) signal embedded in them, which means that the readings can be synchronized with other readings throughout the distribution system to give grid operators a comprehensive view of grid conditions. 

PMUs and all other sensors that utilities are adding to their grids collect huge amounts of data. To this data, add in the automation signals that utilities will be sending through things such as advanced distribution management systems, fault location isolation and service restoration and voltage management technology, Then add the data received from drones, the signals going to and from smart street lighting systems, as well as the control signals that will likely be connected to electric vehicle charging infrastructure. It's easy to see why 85 percent of survey respondents are getting by on 10 gigabits per second (Gbps) of bandwidth now, but 45 percent anticipate needing 30 Gbps in the future. 

Why Private Networks?

Let's go back and re-examine preferences for network characteristics. It appears that survey responses reflect utility professionals' reality more than their wishes. 

Even though half of respondents prefer a private network to support their private electric operations, roughly 8 percent names "licensed versus unlicensed" as their most important network selection criterion. This isn't because they don't really care if a network is licensed exclusively to them; it's because the lack of private spectrum available today makes most utilities shrug off that preference and assume they'll need to settle for an unlicensed option, not understanding the risks associated with the high costs to resolve the potential interference issues over the life of the unlicensed network. 

Maybe they won't.

More than half (52 percent) of respondents said they would consider leasing spectrum for 10 to 20 years at market rates that could be capitalized for their private wireless network. Although 52 percent say they don't know how much spectrum they'd need, a majority will need more than 5 MHz (MegaHertZ) or greater to support their grid modernization initiatives. This might be achieved through leasing spectrum long term from spectrum owners that can be capitalized if structured correctly with the network implementation. 

Ultimately, new spectrum solutions will be needed because utilities must modernize their grids to accommodate new distributed generation and other technologies. To do that, to add automation and sensing digital technology throughout the distribution system, you need a sustainable communications network that is not prone to interference and that has increased bandwidth and reliability.

Communications are the one common thread tying all grid modernization efforts together. After all, two things make grids smart: computing power and communications. Computing power won't get you anything without communications network in place to make data control signals go where they need to go.