By Nathaniel George and Felix Julien
Engineers at Dominica Electricity Services Limited (DOMLEC) are looking forward to the day when they can use data from advanced metering infrastructure (AMI) for better system modeling. Service personnel will use these data to map outages and verify restorations. Vegetation management staff will use AMI’s information to prioritise workload. In fact, like people at most utilities, all of DOMLEC’s employees expect AMI to improve operations for almost every department in the company.
There is a common theme behind the many benefits that are anticipated to come from AMI: Almost all of them translate into better service and higher value for the utility’s customers.
ROUGH WEATHER ON THE WAY
Take outage management, for instance. It is so very important to us here at DOMLEC because the Commonwealth of Dominica, our island nation, sits in the Atlantic Ocean’s “hurricane alley.” Here, fierce storms are a way of life.
Hurricane season officially runs from 1 June to 30 November. Unofficially, the Atlantic Oceanographic and Meteorological Laboratory has found that “peak” hurricane season runs from August to October. According to the lab, those three months bring 78 percent of tropical storm days, 87 percent of “minor” hurricane days and 96 percent of “major” hurricane days to DOMLEC’s service territory. With an average of 10 to 12 hurricanes or tropical storms per season, we could be hit several times in one year. Before we fully recover, we may be right back in the eye of another storm.
Fortunately, we anticipate that AMI will help us restore power for our customers more efficiently. That is one of the many customer-focused reasons our utility has purchased an Elster EnergyAxis® System and plans to install it on 27,000 meters during the next three years.
When people see hurricane coverage on TV, they see the wind and rain. What they do not see, but equally dangerous, are the terrible landslides that result from a hurricane’s downpour and flooding. In Dominica, damage from landslides adds another dimension to the wind and water destruction typically experienced during hurricanes.
Dominica, also called “The Nature Island” because of its unspoiled natural areas, is densely forested and very mountainous. Although the island, approximately 46 km long by 26 km wide, measures only 754 km2, there are 365 rivers, some of which have enough volume and pitch to support hydroelectric generation plants. There are three small hydroelectric plants on the island.
In 2004, 41 percent of the overall island energy was generated from hydro, while the rest was generated from fossil fuel. During the year 2007, Hurricane Dean badly damaged the Padu Hydro plant, which required us to pursue load shedding for a few months. As a result of damage sustained to the distribution system, and because we did not yet have AMI, it was difficult to ascertain which customers had come back on the system. In fact, a police station was overlooked during the restoration efforts. Power had been restored to the area, but unwittingly the station was left without power for more than a day longer than others in the neighbourhood.
That is the kind of mishap that the DOMLEC team hopes AMI will change. The AMI system will be used to target critical service connections, such as medical facilities, police stations and hurricane shelters, and ensure these customers get priority when linemen are sent out to repair storm damage. It is the expectation that AMI will provide the information that will eliminate problems such as a police station or other important community institutions being left without electricity after power has been restored to other customers nearby.
Along with outage management, our DOMLEC engineers will use AMI to help us with system optimization. For example, we hope to pinpoint our highest areas of losses by using AMI data to do energy balancing, which means we will compare energy going into a circuit with the consumption we record at customer premises when we read the meters. The difference between the two measurements may be technical or non-technical losses. Like most utilities, we have some of both, although we expect AMI to lessen them.
Here at DOMLEC, many of our technical losses are related to asset sizing. We may have transformers that are too large in some areas. And we know we have some lines that are too small, so we have a lot of loss due to heating.
However, AMI data will help with system modelling and asset placement. It will provide detailed information on circuit loading and help engineers spot anomalies before problems arise.
GAINING CUSTOMER INSIGHT
We also believe AMI will add value to DOMLEC’s most popular product offering, prepaid metering, or as we call it Pay-As-U-Go. Some 20 percent of our customers have prepaid metering, and the service represents about 10 percent of our revenue.
The prepaid metering programme was launched in Portsmouth, our second largest community, and the home to Ross University Medical School, a US-based college. Because of the school, there are many students in the area who rent dwellings. Landlords love the Pay-As-U-Go program because they previously had been left with unpaid electricity bills and they had to pick up the costs. As a result, we launched this program in 2003, and it has become very popular with both landlords and students. Most of the apartments in the Portsmouth area have prepaid meters.
Indeed, the Pay-As-U-Go program is so popular that students actually request it. Many of them will only rent an apartment that has prepaid service. One reason is because prepaid metering gives people control over their electricity consumption. The inhome display they use to enter token numbers also allows them to constantly monitor how much electricity they’re using. In fact, these customers generally use less electricity than customers in comparable households. Consumption reductions in the area of 15 percent are not uncommon.
Because we do not read prepaid meters, we gather no information from approximately 20 percent of our meters. What’s more, we don’t visit those customers except to perform routine consumption-exception checks. Therefore, we may not know if a meter is malfunctioning. These are drawbacks of prepaid metering, but we can mitigate them with AMI supporting our prepaid offering. Our EnergyAxis System will give us a two-way connection with our prepaid customers, and that’s something we do not currently have.
MORE ANSWERS FOR CUSTOMERS
In many ways, we expect AMI to help us serve customers more effectively. Our EnergyAxis System will give us remote connect and disconnect capabilities, so we can respond to customer requests quickly and save our rate payers the cost of a service call.
Plus, we will be able to answer high bill concerns, as the system will allow us to recheck a meter reading as soon as a customer calls with a question.
With AMI data, we will be able to look at loading on specific transformers and sections of line, as well, and we will be able to see that loading in near real time. That will let us know in advance where we need to make changes to avoid problems. It will help our engineering staff choose locations for things like capacitors, decide where to increase the capacity of feeders, change locations of transformers, and take other actions to improve the voltage profile of the entire system.
AMI data also will help us deal with damage claims. Right now, we estimate that we receive approximately 300 claims per year that require us to pay out a total of some US $60,000. Claims often are associated with power interruptions and voltage problems that customers say have occurred and damaged their equipment. Without AMI, it is very difficult, if not impossible, to verify that these service interruptions or voltage problems actually did occur.
Once we have the ability to detect what the voltage was or whether we had service problems at this meter on the date in question, it will help us manage claims more effectively. And, AMI data will help us detect system problems before they become quality problems for the customers we serve. The information gathered from AMI will be invaluable in fostering a more transparent relationship with customers and the regulators. We hope to save time and expense for everyone.
Vegetation management is another area where we have gone on a cost cutting mission. It is one of our utility’s top operating expenses, as we have to trim trees all year long and, often, we trim the same trees more than once annually.
In 2002, we redesigned our approach to vegetation management to lower our cost per mile on lines cleared and keep lines clearer longer with each trimming. The new approach not only saved money, it reduced our number of outages by as much as 62 percent in certain areas. But, with AMI, we can do even better.
We plan to integrate our EnergyAxis System with our Geographic Information System, which provides us with maps for all services and assets connected to our grid. To support more efficient vegetation management, we can use the statistical data showing how many momentary outages there are on a particular section of line or meter in order to know if there’s a problem we need to investigate. And, if we find data that indicates a tree limb may be hitting a wire, we will use that data to plan trimming in the area. AMI fits right in with our goals to deliver reliable service as cost-efficiently as possible.
While DOMLEC won’t implement smart grid automation in the near future, it is in our long range plan, and we will add automation to our grid as budgets allow.
For one thing, we want to add sensors and control devices to our system. Terrain makes it problematic to get to many places on the island, which means that if we can get the system to operate with as little human intervention as possible, it will dramatically cut costs.
We also anticipate an expansion of renewables, because ours is an ecologically minded population. We think consumers will want more renewable options, and we will be ready to link them to our system.
Such smart grid applications are part of the reason we chose EnergyAxis. We expect to leverage this two-way connection with customers when we are ready to add smart grid functionality.
The mesh network gives us a self-repairing communications network that will ultimately serve as our smart grid backbone. It already solves many problems and issues we face today. We believe it will meet challenges we will face in the future, as well.
Finally, we recognize that one can have the best technology available, but if one doesn’t have the right set of people with whom to conduct business, one’s project may not work out as planned. From the time we started exploring AMI, we found some very sincere and easy-to-work-with people at Elster.
Buying an AMI system isn’t just a purchase, it is the start of a new relationship. So, it is important to have a solutions provider who understands that the relationship doesn’t end when the AMI contract is signed. That is when it begins. We feel confident and comfortable moving forward with Elster.