Dual purpose networks

Tantalus WANWith a desire to control their own destiny, a number of electric utilities have built out their own communications networks. While utilities deploying fiber and their own networks is not necessarily new, what is new is that some municipal electric utilities, often to the chagrin of the local incumbent service provider, are building networks that will serve both the utility themselves and other constituents including local government, schools and, in some cases, residential customers.

At the core of these networks is some kind of fiber implementation. The way these networks are used depends on the utility themselves and sometimes regulatory barriers they face. Fiber has been at the forefront of many smart energy deployments, as seen by municipalities such as Sun Prairie Water & Light (SPWL), Pulaski Electric System, and Washington's Mason County PUD. Looking at just these three municipalities alone, smart grid strategies are quite diverse.

Mason County PUD logoMason County Public Utility District No. 3

Washington state's Mason County PUD has built out a multi-purpose Fiber to the X (FTTX) network to sell wholesale capacity to other carriers, as the state prohibits any utility from offering retail telecom services.

Sun Prairie Water & LightSun Prairie Water & Light (Sun Prairie Utilities)

SPWL, located in Sun Prairie, Wisc., built a Fiber to the Business (FTTB) network for local schools, government, and public entities (emergency, police, etc). However, SPWL's motivation to build out its fiber network wasn't initially for its own needs. It was actually driven by a request from the local school that was trying to upgrade its communications infrastructure and had no luck in getting a fair price from the local ILEC it turned to SPWL. 

"The school district approached us around 1998 and asked us if we would provide telecommunications services for the school district," said Gary Sanders, general manager of SPWL Telecom. "They had gone out for quotes and the local ILEC quoted $1.2 million and the MSO decided not to quote it. The utility manager at the time saw it as an opportunity and drew out a loop using our existing electric infrastructure and found out we could do it for about $200,000."

Pulaski Electric line servicePulaski Electric System

Tennessee's Pulaski Electric System built a retail/wholesale FTTH network to deliver retail triple play services. Because Pulaski's electric utility reach extends outside its footprint, the utility decided to deploy a hybrid fiber/microwave network with Enablence (GPON) and Tantalus (RF) equipment. The utility has built out a FTTH network where it sells retail triple play (voice, video and data) to customers. Initially intended to enhance the local community's broadband access infrastructure, Pulaski later found that the fiber network could be also used for its own internal electric network monitoring needs.

"The FTTH project was part of a community initiative to improve the broadband opportunities and then we quickly understood it would have implications for the electric system," said Wes Kelly, CEO of Pulaski Electric System. "While that was not the initial impetus for it, we saw that things were changing and this very rapid two-way communications would provide us with an avenue to what is now called smart grid for the system."
With its Tantalus 900s MHz wireless system communicates to an IP collector (IPC) point and the IPC brings it back over Ethernet over the FTTH network. Currently, Pulaski has deployed new meters to two-thirds of its customer base.

Kelly says with this network configuration they can "just deploy the IPCs on the side of homes of customers that subscribe to our triple play service and if their neighbor next door doesn't subscribe to our broadband services it's meter communicates to the meter across the way and brings that data back."

Dual purpose networks
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