AMR when it really counts
Utilities are adamant that the advantages of remote meter reading are more than simply welcome conveniences – they’re essential to their daily operations. Remotely reading meters can protect employees from hazardous situations, alleviate significant utility expenditures and help assure a consistent supply of electricity to customers.
Of these important benefits, employee safety is the most important. Southwest Louisiana Electric Membership Co-operative (SLEMCO) brings power into a coastal area where the meters are spread throughout a trackless bayou region. In a part known as Vermilion Bay, fishing, hunting and trapping are a way of life for many. No roads penetrate the marshy land along the northern coast of the bay. Families reach their weekend cabins and hunting camps by boat, which is not that simple. The wake from huge offshore crewboats continuously threatens to overturn the smaller boats – and there’s the real possibility of encountering hungry alligators that lurk in the swamps nearby!
Safety was a real issue for the SLEMCO meter readers. Employees had to travel in pairs by boat to read the 100 meters along Vermilion Bay. It took them nine hours or more, and it was very costly. On one trip, the meter reading crew was thrown into the water when their small boat capsized in the wake of a crewboat. No one was hurt in the incident, and there were no alligators nearby to threaten the crew, but it was a vivid reminder of the dangers they faced.
Since then, SLEMCO has equipped each of the customers on Vermilion Bay with a Turtle® system transmitter that sends daily meter information directly over the power lines to the utility office in Lafayette. Certainly the Turtle AMR system saves SLEMCO time and money – but those concerns are small compared to the utility’s concern for the crew’s safety.
AMR SAVES TIME AND MONEY
While AMR helps all utilities cut operating costs to a degree, some utilities save critical amounts of money through remote meter reading. David King of Northwest Territories Power Corporation in northern Canada said that until they installed Turtle AMR systems, meter readers had to make trips of up to 1½ hours each way just to read a single meter.
Frequently, when we didn’t have meter readers available, we had to have line crews make trips in to read these meters," he said. "That was very expensive. And in addition to the monthly reads, there were times when we had to re-read the meters, or get a final reading when a customer moved. Further complicate that by having the meters buried under several feet of snow in winter, and you can realise how important remote meter reading is to our utility."
Meter data from AMR systems can also be used to perform diagnostic checks on distribution grids. Mark Stubbs, general manager of Fort Belknap Rural Electric Co-operative in Texas, discovered data from their Turtle system helped maintain their distribution system and cut line loss significantly.
"We started installing Turtle transmitters in November 1997," he said. "At that time, our line loss was running 12.22%, but was reduced to 11.47%. That .75% reduction can almost entirely be attributed to Turtle AMR. It will result in an annual savings of about $30 660. On line loss alone, our payback on the first 1700 Turtles will be 3.27 years."
Perhaps AMR’s greatest impact is upon expanding electrical systems in developing countries. Myk Manon, regional manager in Central America for NRECA, deals with the challenges of the area’s evolving electrical distribution systems on a daily basis. He sees one of the greatest needs to be the importance of accurate metering.
"In many upper-level income neighbourhoods, the streets have limited access, controlled by guardposts and blockades," said Manon. "This not only delays meter reading, but many meter readers will avoid reading the meters in these areas altogether; they’ll just guesstimate the reading."
Meters are often placed high on a pole or building, and then meter readers try to read them with binoculars. "That’s hard to do," says Manon. "You have to find a pair of binoculars that have a close focal range, otherwise you have to move across the street to read the meter and you completely lose the advantage of the binoculars. Just try to read a cyclometer with digits four millimetres high and 20 metres away with a wind blowing!"
Many utilities are able to use meter data returned via AMR systems to perform diagnostic checks on their distribution grid. AMR systems with capabilities to record momentary outages continuously can identify problems on the lines that could become full-blown system outages. In 1997, Wood County Electric Co-operative in Texas discovered an abnormal amount of blinks showing up on their meter reads.
Customers became concerned and started calling the utility for answers – not easy to establish, as some meters were indicating only two blinks a day, while others were showing as many as 25. The utility suspected that the blinks were resulting from occasional surges of current on the line, followed by reclosures, but the technicians had no idea where it was happening. A crew drove through the substation area and could find nothing.
Utility personnel decided to post the blinks on a map, and discovered that one section of line was experiencing the greatest number of outages. A crew was dispatched to the area, where the line ran through a creek area off the road. They surveyed the line on foot, and discovered a dead buzzard hanging from a line, with one wing brushing the other phase of the line. In the breeze, the wing would touch the line and current would arc across the lines, causing the brief outages. The crew was able to knock the bird down with a hotstick – a small task compared to surveying miles of line to find the problem, or worse, experiencing a major outage.
Remotely reading meters will continue to be important to utilities that use AMR simply to streamline utility operations, relieve customers of reading their own meters, or make it easier for meter reading personnel. But then there are times when metering really counts – and that’s when AMR becomes more than convenient.