This four-year-old entity buys and sells a broad range of services for its municipal and public power utilities. Utilities Plus and its 14 area members needed to capture real-time meter and system status information so that operating decisions could be made quickly and cost-effectively. They decided that it was time for a load aggregation system. The vendors vying for this new system were quoting in the $250,000 to $300,000 price range, a cost that was considered expensive.
"That's when we decided that our new, existing SCADA system could be used to aggregate the load," says Paul Leland, Manager, Blue Earth Light and Water, Blue Earth, Minnesota. One of the Utilities Plus members, Blue Earth Light and Water recently replaced its original Landis & Gyr network with a QEI 2000 Frame Relay SCADA (Supervisory Control and Data Acquisition) system. The new QEI system uses a distributed 64-bit RISC workstation architecture to provide the maximum performance, flexibility, and scalability to meet Blue Earth Light and Water's needs. The system was supplemented with a Data Comm for Business (DCB) Broadcast Polling FRAD (Frame Relay Access Device.)
"We decided to throw our hat into the ring and demonstrate to the other members of Utilities Plus that we could effectively use our new SCADA system to create a network cloud and aggregate the load," Leland explains.
"Over the past 6 months we had been working on pieces of the system, including the communications side. We needed to develop some kind of wide-area communications scheme to meet our load aggregation requirements. We needed a low cost, easily maintainable, highly reliable communications product, and that's where the DCB Broadcast Polling FRAD devices came in."
QEI recommended the use of DCB Broadcast Polling FRADS, which work well with any SCADA system. Essentially, the DCB product is an async FRAD that allows multi-point polling over Frame Relay networks via RS-232 interface. Each master FRAD supports up to 160 remote terminal units (RTUs), and is more cost effective than multi-point polling modem networks.
At a cost of just hundreds of dollars for each master polling FRAD, the DCB units helped to ensure that the communications cloud could be completed at a cost well below what vendors had been proposing earlier.
Cost-effectiveness was very attractive to Blue Earth Light and Water as well as the Utilities Plus organization. They had considered an Internet-based communications alternative because it would have been practically cost-free.
"We talked with several vendors who said they were already working on Internet-ready RTUs and Internet-ready meters, and so forth," Leland explains. "But I don't think we could rely confidently on an Internet-based system yet." Leland says he was especially concerned with technological trade-offs involved in integrating Internet-based communications with SCADA systems that are continuously polling and relatively time-sensitive.
"If we move to the point where we're monitoring load and coordinating the control of our generation assets as one logical entity, I just don't think we can use the Internet at that point. There are big issues with reliability and other timing issues with existing SCADA systems. Are we going to rely on the Internet for that kind of control? What if an Internet communications delay or failure jeopardized a power generation system at a critical point in time? The cost could be enormous in today's energy market. I'm sure there will be a place for the Internet communications for this type of application at some time in the future, but it's probably going to be a few years from now."
Another factor influencing the situation: a large investor owned utility, which sets the engineering benchmarks for power companies in the local region, provides standards on new generation equipment.
"They have all sorts of engineering specs," Leland says. "And one of the current components is a communications tie between the new generation equipment and the IOU's control center. We have four or five cities that have fallen under these new engineering standards, and they are meeting the communications requirement via costly leased lines. Our new system will be able to eliminate those costs. Plus, once we aggregate all this data over our Frame Relay network back in Blue Earth, we will probably include the IOU in our frame cloud and just pass on all of the aggregated data to them from here in Blue Earth."
Interestingly, while the Internet did not offer a viable solution to Blue Earth Light and Water's network communications requirements at this time, it aroused some other interest. Because some member cities in the Utilities Plus group have no access to DSL or ISDN Internet connections at this time, it may be feasible to offer a substitute high-speed/high-bandwidth service to these cities via the SCADA communications cloud.
So far Blue Earth has installed 6 Broadcast Polling FRADS and will be ordering another 6 to 8 units as the other cities in the Utilities Plus organization get connected. Leland says the goal is to have that done by May 1, 2001.
The DCB product was recommended by QEI, who told Leland that even though they have their own hardware, DCB seems to be genuinely technically qualified.
"They're not just there to sell hardware," Leland explains. "I got a good feeling from DCB. Now I would tend to use their service for any type of communication question in general. They seem to be quite innovative and yet personalized." ET