Building A Future Friendly Network

It wasn’t long ago that smart metering technology was defined by the type of communications network it employed – RF, PLC, BPL, POTS, and Paging Network to name a few.

“TUNet network clears the path for adopting a full range of Smart Grid services and creating a distribution system in which consumers and utilities play an active role in reducing both consumption and costs”
-Wes Kelley, EVP and Chief Marketing Officer, Pulaski Electric System

The lines between technologies were as clear as those separating chocolate, vanilla and strawberry in a tub of Neapolitan ice cream. The problem was that vendors would give you a scoop of a single flavor, but couldn't offer a taste of everything. It was a classic "either/or" dilemma.

Utilities today must focus on a much broader range of strategic needs. Nothing less than a two-way, near real-time, multi-commodity network that supports Advanced Metering, Demand Response (load control & smart thermostats) and Distribution Automation is realistic for the long term - regardless of whether a utility's automation plans are basic or extend deep into Smart Grid territory.

Current popular communications choices include radio frequency (RF), broadband over powerlines (BPL), cellular (GPRS, GSM), fiber (FTTH, FTTP) and WiFi. On the horizon are WiMAX and other standards that have yet to be finalized or become prevalent.

In other words, a utility may want chocolate for now, but expects to enjoy vanilla and strawberry upgrades as its needs expand. (To say nothing of sprinkles, whipped cream and a cherry on top.) And these advanced capabilities must be ready to be switched on when the time is right, without creating insurmountable technical barriers, associated costs or end-user inconvenience.

All-or-Nothing Approach Too Risky
While there are increased business drivers and incentives - both economic and environmental - to deploy Smart Grid communications now, utilities are challenged to select the configuration that will provide an optimal technical solution over the long term. Making a significant capital investment without clarity on uptake, cost recovery, or regulatory framework makes an all-or-nothing approach too risky - especially in an industry where infrastructure investments are expected to last multiple decades.

It's no wonder that many utilities are edgy about making a commitment when only a few of today's popular communications options existed in a recognizable form a decade ago.

As the case studies below illustrate, it's now possible to mix-and-match options and implement a hybrid or overlay solution that is flexible, scalable and adaptable to next generation technologies and standards.

Those responsible for Smart Grid procurement decisions should start by asking five basic questions:

1. What does the system need to do now?
2. How can this best be achieved?
3. Is there sufficient capacity for data intensive applications and increased network traffic?
4. How easily can the system adapt to new and additional needs in the future?
5. How cost effective is its adaptability?

Utilities that address this challenge successfully start with a network that can readily embrace future functionality by deploying a system that allows multiple WAN alternatives to co-exist.

The strategies outlined in the following case studies show that significant operational, business and customer service benefits are within reach. The most important thing is to arrive at a meaningful vision, a flexible implementation model and the right technology platform to build on. 

Pulaski – Uniting Wired & Wireless Worlds
Pulaski Electric System (PES) is a Tennessee-based electric utility that leveraged its existing infrastructure by combining the reach of RF and the speed of Fiber to the Home (FTTH) to provide total territory coverage and operational efficiency.

PES is a municipal utility that delivers power to 15,000 homes and businesses in town, as well as several outlying communities and farms spread around the county.

In 2007, Pulaski implemented a FTTH network to provide residents and businesses with high-speed internet access as well as high-definition video entertainment and high-quality digital phone service. However, extending FTTH to remote communities and isolated farms was not practical given the low density of potential subscribers.

For this reason Pulaski selected an AMI system that could operate in both wired and wireless worlds.

TUNet® - the Tantalus Utility Network - enables Pulaski to use both its existing FTTH network and 220 MHz RF for rapid and reliable two-way data transport. PES gets more value from FTTH by using it for triple-play media and as its AMI backbone. Furthermore, it can quickly and easily bring Smart Grid functionality to customers on the edges of its service territory via the wireless network, where customer service costs are highest. This minimizes truck rolls, removes high-cost reads and ensures that all customers receive the same high level of service, regardless of location.

Although the TUNet AMI system operates in both IP and RF environments, at its core it is a single network. This simplifies integration to other critical systems, provides a comprehensive coverage solution, and facilitates migration from RF to FTTH as the fiber network is expanded.

By choosing TUNet, PES avoids the costs and complexities that would have resulted from maintaining two separate AMI networks, including  the computer systems,  as well as the applications and skilled people that make them work.

A hybrid Wide Area Network (WAN) offers the scalability and capacity that will enable PES to implement demand response, energy-efficiency programs and in-home displays to whatever degree is desired without retooling the entire network - or worse still, starting over.

AMR as the On-Ramp to the Smart Grid
Early adopters of AMR are on the other side of the fence. Their challenge is how to continue to get value from an existing system in a rapidly changing world.  

How can a utility adapt to additional needs like DR & DA while positioning itself for longer term needs such as Distributed Generation? Deploying parallel communications isn't an acceptable approach from cost, integration or operational perspectives. On the other hand, writing off recent investments doesn't make much sense either.

It puts many early adopters in a quandary:

1. Continue to use outmoded technology and fall behind in functional capabilities
2. Deploy a new AMI network but write-off assets, often years before ROI is realized

Neither of the above is acceptable - or necessary!

Most vendors offer upgrades from a legacy AMR system to a two-way network. But is it really an upgrade or a wholesale changeout involving new technology at substations, injection sites and all? Most utilities can neither afford, nor get political support, for such an expensive proposition.

Even if these upgrades are cost effective, do they just delay the inevitable? Is the pipeline too narrow for TOU & CPP pricing Demand Response or other applications? Will a utility have to pick which features to implement and which to ignore because there isn't sufficient bandwidth or bit rate to support everything desired?

One alternative is to gradually replace AMR with AMI. An "overlay" strategy allows a utility to continue to get value from its original AMR system while methodically deploying two-way communication to those locations that justify additional functionality.  

This approach takes advantage of TUNet's surgical deployment capability. Furthermore, it is not tied to a particular backhaul method. A utility can choose whichever WAN option it desires - RF, WiFi, FTTH, GPRS - and expand as needed.

For example, it could target high-need, high-return C&I accounts which are currently under-served by the existing technology. It could begin TOU pricing and/or load control programs at volunteer homes in order to engage customers in conservation. Or it could cost effectively validate market approach before full deployment or customer promotion is initiated. There are multiple departure points. Just go where the business case is most compelling; pick the low hanging fruit.

Yes, an overlay approach requires an investment in new technology, but typically not nearly to the degree of a complete system refurbishment, and with much more effective risk management and targeting.

The advantage it brings is a simple, cost-effective migration to a communications method that has the speed, capacity and scalability to support the data-intensive applications that will likely be mandated in the near future. What's more, concurrent use of TUNet with an existing AMR system prevents a premature write-down of the existing one-way system. The transition is step-by-step and proceeds at the utility's own pace.

Crystal Ball Considerations
The evolution from AMR to AMI to Smart Grid teaches that it's wise to over-build your communications network. Increasingly, the WAN backbone will be required to work harder, faster and carry a bigger data payload as advanced functionality makes its way onto the grid.

The same network that delivers kWh usage, outage notifications, sag & swell alerts and power quality measurements today will be used tomorrow to transmit demand response and load management messages, TOU price alerts, event opt-in or opt-out confirmations, green energy availability notifications, as well as query and control Distribution Automation equipment. In the near future, it may also be called upon to execute Distributed Generation actions and coordinate cold load pickup schemes.

The list gets longer as the potential of the Smart Grid comes into clearer view. Expectations keep pace with innovation stride for stride.

The only sure thing is that an inflexible infrastructure will limit a utility's ability to evolve. What seems to be a good fit today may hamstring future functionality. Nobody wants to get caught in a situation where the life of the asset falls short of the projected payback period. You want to keep your options open.

We all know what happens when cities fail to anticipate growth and construct the requisite infrastructure - grid lock.

A hybrid network allows a utility to hedge its bet and move in the direction that is most likely to succeed. This way, a it can mix and match current systems with those adopted down the road, as the communications network grows from a footpath to a super highway.

Tantalus Lab