Pipeline & Gas Journal
February issue 2000:

SCADA Proves Crucial

Communications Gives
Utility A Competitive Advantage

by Bill Chapman,
Communications Manager
Intermountain Gas, Boise, Idaho

Over the last 30 years, the utility industry has invested billions of dollars in control and communications systems technology, investments typically justified by achieving operational efficiencies and incremental cost savings. In the last three to five years, however, this has changed across all types of utilities (i.e., electric, water, or gas), where operational considerations are, at best, only a part of the decision to invest in these technologies. The operative question now is, “how will this technology/system/application help us compete and improve our bottom line?”
At Intermountain Gas, both operational and financial needs have driven the company’s investments in its supervisory control and data acquisition (SCADA) and communications systems. Over 100 major industrial customers are presently on service. Fifty-eight percent of the company’s gas sales are for industrial use with commercial and residential segments using about 16 percent and 25 percent, respectively.

Incorporated in 1950, Intermountain Gas Company is a privately owned natural gas utility, based in Boise, serving southern Idaho in an area that includes 74 cities and 23 counties with a population of over 800,000 spread over 50,000 square miles. As a result, unlike utilities that have more compact service territories, Intermountain’s is a major challenge for design of a SCADA system.
For the many safety and operational needs, SCADA is a necessity for a gas distribution company, but using this system and its communications infrastructure to better serve customers is where Intermountain Gas has realized a great deal of benefit at the bottom line. With the advent of open energy trading, companies that do not take care of their customers today will not be around tomorrow.

This competitive environment has brought significant change to business practices, and as a result is how SCADA and communications systems are managed. One change is that the company is very committed to outsourcing of tasks and operations that are determined not to be a part of the core business. This means that Intermountain’s management must have a high level of confidence in its supplier’s ability to deliver. A second change is an increasing commitment to providing customers with additional services beyond “traditional” utility service. In this environment, customers routinely demand much more information as a part of their service.

At the heart of Intermountain’s customer service and information efforts is its SCADA and communications system. The SCADA system, from Bristol Babcock (Watertown, CT), is used for managing the pipeline system’s performance and capacity, forecasting consumption, and — importantly - for metering gas usage at each of Intermountain’s 100+ large industrial customers. “This system gives Intermountain the ability to manage its large customers usage on a daily, or even hourly basis,” says Dan McAlister, industrial services manager. He and the gas control staff spend a large portion of each day working with Intermountain’s large industrial customers to ensure that they have the information they need to make their own operating decisions based on their energy needs.

McAlister adds that “we are also able to do a better job of managing our “firm” customers (who receive gas at all times) and our “interruptible” customers (those who buy gas at a lower, but interruptible rate). Having a reliable communications infrastructure in place makes these levels of customer information available.

The communications system has been a major facilitator in making SCADA both an operational and a competitive tool. Using Multiple-Address radio frequencies, the SCADA data travel by radio from each customer meter to one of six strategically located full-duplex redundant repeaters across Intermountain’s service territory. From the repeaters, the data is re-transmitted to five regional offices, and is then sent across a frame-relay network to the central gas management office. The system also has radios transmitting and receiving data from a dozen city gates where Intermountain receives product from its major gas transporter.

All of the radios used on this system including the fully redundant repeaters are from Alligator Communications (Santa Clara, CA). When the system was initially implemented, Intermountain used leased telephone lines from several local companies.

With the installation of the new radios, Intermountain has solved a number of technical and business problems. First is reliability. The radios are virtually maintenance-free, due in part to GatorTrac, Alligator’s patented frequency calibration solution by which each remote radio is constantly calibrated to the master radio’s internal frequency reference. Should the radios require maintenance, repairs or replacements are quick and relatively low cost. Using a system of “Warehouse Spares,” a simple radio change-out in place keeps the system running. Additionally, the freeze and thaw problems previously experienced are no longer an issue.

Costs associated with implementing and maintaining the system have also been reduced. The radios were less expensive than other alternatives and their reliability and low maintenance requirements have kept the costs of this system down even as it grows. Over the long term, substantial cost savings have been realized by not having to pay monthly lease fees to a leased line provider.

This system has its share of technical challenges, foremost being the relatively large geographical area that must be covered. The six full-duplex repeaters are located at elevated tower sites across the area, each programmed to know which field radios it must talk to. When a particular site fails to report, a message appears at the gas control center and appropriate actions are taken to restore communications. This intelligent communication system makes the necessary continuous flow of information between the large industrial customers and the central office possible.
The business and technical challenges may seem daunting at first glance, but implementation and operation of this system have proven to be easier and less expensive than originally thought, while providing improvements in reliability and customer service. Today’s increasingly competitive operating environment calls for nothing less. P&GJ