March 29, 2024

New Adventures in Submetering
Going beyond the billing meter to increase visibility into energy usage data and create greater efficiencies

by Vance Hall, Vice President, MeterSmart, L.P.
For years in the utility industry, submeters were viewed as a collection of rather simple measurement devices used for one main purpose – utility bill allocation. Later, the manufacturing world discovered that submeters could be valuable tools not only in allocating, but also in analyzing, managing, forecasting and controlling energy usage. In this role, submeters act as a helpful window into the energy consumer’s business processes.

Load Research Project Checklist

  • Sample Design and Selection

  • Customer Recruitment

  • Customer Site Survey

  • Equipment Procurement

  • Equipment Installation

  • Commissioning

  • Data Collection with VEE

  • Reporting

In the electric utility world, the story is different. Here the submeter has not played a significant role until very recently. Today, new uses for submetering technology are being realized by utilities to enhance load research programs, measure energy demand and provide important data for marketing programs that offer customers a chance to track their own energy usage on the Web in the middle of a billing cycle. All of these new uses are finding a place as valuable customer retention tools for leading utility companies.

In a world of costly blackouts, high energy demand and high energy prices driven mostly by high natural gas prices and low generation and transmission capacities, utilities are beginning to use submeters as tools to help their customers reduce operating costs and drive loyalty, especially among commercial and industrial business customers.

Effective Load Research
With numerous technological advancements and rising costs facing the electric utility industry, utilities are doing more homework. Case in point, load research programs and individual customer research efforts are gaining popularity because of their ability to show utility customers when and how they can save money on the monthly energy bill. Capabilities made possible by today’s more advanced submeter are playing a critical role.

Electric load research provides end-user data with a wide range of uses. It is the basis for costof- service studies used in the ratemaking process; the driver for load profiling for billing and settlements; and the enabler of demand and energy requirement forecasting. It also proves value in the creation or revamping of utility marketing programs.

Load research involves the process of defining the population or target customer segment to be analyzed, creating a sample design that accurately represents the target, selecting the sample set of customers, recruiting the sample of customers, installing interval data recorders, collecting and analyzing the sample data and finally reporting the results. The objective in recruiting the sample set of customers is to obtain as many of the primary sample customers as possible or a certain amount of bias may enter into the sample. To minimize the amount of rejections of the primary sample set, care must be taken in the recruiting phase of the project.

In past years, metering with interval data storage capability was large and bulky, therefore customers often rejected them because they did not want a large, unsightly piece of equipment installed within or attached to their premises. With the advent of electronic metering came smaller recorders under glass, which are less intrusive. One issue remained, however, which was that installation of the recording equipment required a service interruption in order to install the research meter. This presented a problem for the end user.

For most residential customers this was not a major issue, but for most commercial and industrial customers turning off the power isn’t even an option. A service interruption at a large industrial facility means idle workers, wasted wages and compressed deadlines for products and services – all very costly predicaments. Therefore, installation was most likely deferred until a time that would cause the least impact to the industrial customer. In turn, this meant overtime expenses for the utility to have workers install meters on the weekend or on a holiday. For smaller commercial customers, like a dentist office or a small grocery, a service interruption means the business cannot service its clients during the outage, which affects their ability to earn an income.

So what is the impact of customer rejection? In the context of load research, it leads to inaccurate data. For example, if all customers that refuse to let a research meter be installed because of the service interruption are rejected, the sample becomes one of only customers that will allow a service interruption and not a representative sample of the target population. These customers could easily have a different set of energy usage patterns than the population-at-large.

The latest submeters solve this predicament as they can be installed without a service interruption to the customer. Split-core current sensors are installed around the conductor or wire, thereby maintaining continuity of service to the facility. This also allows the submeter to be installed behind the billing meter, yet on the same supply circuit; therefore, accurate load profile information is obtained as it comes from the same power supply line as the billing meter. Removing the service interruption requirement virtually eliminates customer rejection once the utility customer is educated on the benefits and added control they’re given over their own energy use.

The next hurdles are hardware and software compatibility, ease-of-use and cost of communications. Most utilities use a standard interval data-collection software platform that reads and stores interval data in 15-minute increments from their billing and research meters. But most submeters are not directly compatible with this software and data must be gathered by one software platform, translated to the utility software, then handed off to a display medium or Web presentation tool. This is obviously very cumbersome, prone to error and expensive to say the least. Therefore, meter and software compatibility as well as a simple display medium (i.e. Web presentation) are essential elements to any effective program. A seamless approach is desirable for both utility research and "end customer" usability. Energy information stored on a secure Web site allows both the utility and the customers to access the data from any Web enabled location to assess energy usage data in near real-time. This allows proactive decision-making and rejuvenates demand-side management (DSM) projects. Program costs are also driven by the cost of communication, if a dedicated phone line is required, installation may take several months and be priced at $30 to $50 per month, plus the cost of installation at $250 to $500. On the other hand, if a shared phone line can be used, the meter dials a 1-800 number in the middle of the night, enabling considerable savings.

Validating Demand-Side Management
One recent project in California is using the benefits of load research to validate an existing demand-side management project. The large investorowned utility is in the midst of conducting a load research study to validate the accuracy of a remotely driven thermostat-control initiative.

The purpose of the program is to measure usage data and confirm the magnitude and timing of reductions in consumption during control periods. In this case, thermostats at a sample group of approximately 150 small businesses can be remotely controlled by the utility to be increased or decreased by between 2 and 4 degrees Fahrenheit.

The desired result, obviously, is to reduce electricity demand during the control period (critical peak demand periods), while providing minimum (often unnoticed) environmental changes at the customers facility. In full turnkey fashion, the California utility had its submetering solution vendor install submeters behind the billing meter to eliminate the need for a service interruption, and conduct interval data collection, processing, analysis and reporting services as well as Web presentation. Again, multiple meters were used as well as runtime sensors on the HVAC units. In each case, the customer’s phone line is shared, which reduces communication costs to the utility for retrieving timely submeter data. Information from the submeter is transmitted in off hours, usually from midnight to 6 a.m., to eliminate interference with business operations. In addition, each submeter is equipped with “off hook detection” that enables the meter to disconnect from the phone line and give control back to the customer if the customer picks up the phone to dial out. The submeter is designed to retry the communication at a later time in the event that “off hook detection” is encountered.

Currently at its midway point, the project has already achieved some intriguing results showing a 10Mw reduction of demand for a one hour period based on 5,000 participants.

Again, the use of industry-standard equipment is key. Compatibility between metering and software means utilities no longer face the burden of trying to maintain multiple platforms for reading interval data; it can all be done on a single platform. This, coupled with the fact that a vendor’s submetering falls within the requirements of meeting billing accuracy standards, makes the submeter a very useful tool in the electric utility industry for load research.

Providing Critical Data for Troubleshooting
Metering used for load research or customer profile information often provides valuable information on individual customer usage characteristics. This information can lead to true and immediate savings for the customer. This is especially true when a utility customer incurs high demand charges for electricity caused by inefficient operation of that facility.

In a real-world example from a Texas-based cooperative, one of the utility’s customers, an Episcopal Diocese retreat facility, experienced an alarming $8,000 increase in its electricity bill. The camp welcomes more than 40,000 visitors annually and likely had a number of places where energy usage could be better controlled. However, the facility lacked proper metering.

To gain visibility into the problem, the utility first installed an interval meter with an associated secure Internet account that allows camp officials to view their own energy usage via the Web. The Coop offers this program to its commercial and industrial customers via the utility’s generation and transmission partner and a third-party submeter and energy information service provider. Camp officials could now view when their energy usage was peaking, but they could not yet see where and, most importantly, why it was going up. This was a perfect job for a bit of customer research.

As the project manager, the Coop determined that submeters should be installed at the camp’s conference center, the chapel and within the facility’s two hotels. The project manager, along with its partners, identified metering equipment that allowed the use of industry-standard interval data retrieval software to retrieve usage data every 15 minutes. And, because the facility has guests year-round, turning off the power for any period of time was not an option. So, the Coop installed submeters with split-core current sensors around the conductor, thereby maintaining continuity of service to all buildings involved in the program.

Soon facility managers were able to see when and where energy was being used, plus the Webbased energy management program from the generation and transmission partner, and automated meter reading and data analysis became a regular part of operations at the camp. With meter installation completed by March 2003, payback for the project was achieved about three months later in June. Equipment costs were covered by the utility, which now had a happier long-term business partner in the Episcopal Diocese facility.

In both of these cases — the validation of the California utility’s demand-side program and troubleshooting at the Episcopal campsite æ the common threads were maintaining service to the facility during installation, and submeter compatibility with industry-standard interval data software. The common lesson? Load research and demand-side management prove that it pays to do your homework.

Vance Hall is Vice President for MeterSmart, L.P. He can be reached at vhall@metersmart.com.