The deregulation of electricity has forced a change in the way that facilities look at energy management. Today, facility executives no longer can simply look at the energy impact of a project or energy use in a single building. The emphasis is on making the entire enterprise as energy cost effective as possible.
With the ability to purchase electricity from practically any supplier, facility executives can select the one that offers them the most beneficial purchase terms. Those terms depend to a great extent on how much electricity is being purchased, when it is being purchased and the shape of the facility’s load profile. In general, the larger the purchase and the flatter the load profile, the better the rates that can be negotiated.
This broader approach to energy management requires that facility executives have accurate information, concerning not only use, but also the time of day energy is used. They need load profiles for the facility. They need demand and power factor records. This information will help any facility seeking to manage electrical costs, regardless of how it purchases electricity.
The first step in managing electricity costs is understanding the how, when and where of electricity use. A facility’s electricity bill provides some of this information, but not enough. Equally important, most bills arrive 30 to 60 days after the use has taken place, far too late for facility executives to take steps to control energy use. To be most effective, facility executives need real-time energy-use information. With real-time information, they can plan actions to reduce energy use and costs, not simply react to bills when they come in.
To accomplish this, facility executives need meters at every electrical service entrance to their facilities. They will also need automatic meter reading equipment and a way to communicate the data back to a central point where it can be processed and read in real-time.
While some energy management systems in the past have included electric meters, few had all of the components necessary to read, process and compile energy-use data in a real-time format.
Today, new electric meter technology, the adoption of standards for the remote reading of meters and advances in the Internet and the telecommunications industry have come together to provide all of the energy-use information that facility executives need in one location.
The new technologies provide real-time system performance data. They allow enterprise-wide access to data for operators, engineers and billing departments. Advanced meters provide power quality analysis by identifying and tracking events that occur in the supply. Finally, meters serve as the data acquisition front end for enterprise energy management systems.
Facility executives have several options for data transmission in metering systems. Traditionally, meters have been read manually. If demand equipment was installed as part of the metering system, those demand meters also had to be reset manually. While manual systems were accurate and reliable, they did not provide real-time information. Even frequent meter readings provided information about energy use after the fact, not allowing actions to be taken to reduce energy use or energy demand. Other systems that can provide real-time meter data have all but replaced manual systems, relegating them primarily to a backup role.
Power line carrier systems for transmitting meter data have been in use in the power industry since the 1970s. Meter data was converted to a high frequency signal that was superimposed on the power line. While the systems were convenient for utility companies, particularly when there was no other transmission system available, they suffered significant problems with corrupted data as a result of noise on the power line. As a result, power line carrier systems have been widely replaced by newer and more flexible technologies.
An alternative to power line carrier systems in applications where there is no convenient way to send meter data back to a central collection station is the wireless radio frequency (RF) system. A small RF transmitter located at the remote meter location transmits the data to a receiver connected to the facility’s energy management system. Although RF systems are not as reliable as hard-wired systems, their reliability is improving. For applications where the meters are located well away from telephone lines or other communications media, RF systems offer a low-cost alternative to running dedicated cabling to the meter site. For two-way communications, the transmitter and receiver must be installed at each end of the communications link.
One of the most widely used communication links between meters and the energy management system are telephone lines. Telephone lines offer reliable, low-cost communications for metering systems. They are well suited for use with primary meters and submeters.
The widespread use of LANs in facilities has provided a low-cost and highly reliable communications system for meter data. In many instances, the LAN is already in place, requiring only a connection close to the location of the meters. Metering hardware is available for a wide range of different LAN configurations, including bus and star-topology Ethernet. LAN-based metering systems are ideal for use within single- and multiple-building facilities requiring extensive submetering.
The latest addition to meter communication systems is the Internet-based system, in which each individual meter becomes a node on the Internet with its own IP address. Data from the meter can then be accessed by any authorized remote system. One of the primary advantages of Internet-based metering systems is low cost. The systems require no dedicated communications infrastructure, and, in most cases, they simply use what is already in place. Internet-based systems also are scalable and flexible. What has led to their rapid growth is the adoption of protocol standards governing meter system operations.
One factor that limited use of meters in enterprise energy management systems has been the historical dominance of proprietary protocols to govern how the meter would communicate with outside devices and how values would be stored in the meter. When metering systems were simple, stand-alone operations, proprietary protocols were of little concern. But as the systems came to be interfaced with building automation systems, proprietary systems became an issue. If a metering system was expanded, or its capabilities were upgraded, system operators often had difficulty getting new meters to work well with existing meters. Even meters from the same manufacturer often had relatively minor changes in the ways in which they formatted and transmitted data, resulting in difficult and expensive software changes to the system. Prior to the adoption of standards, more than 150 different protocols were in use.
In systems where meter-generated data must be shared across multiple users, proprietary protocols pose significant problems. Each application that uses metered data must be modified to accept the data format provided by the meter. In multiple meter installations, each potentially having its own data format, it becomes practically impossible to gather and process the required data. Today’s enterprisewide systems need access to meter data that is provided in standard formats following industry-accepted protocols.
Several ANSI standard protocols adopted over the past few years are helping simplify and standardize metering operations. These standards are a set of fairly flexible protocols aimed at a wide range of metering equipment, including the utility meter, the recorder, a number of add-on modules and data communication systems. The closer a particular product follows the ANSI standard protocols, the easier it will be to use that product in a particular application.
The tables are used to store data collected by the meter, such as kilowatt-hours used over a set interval, while the procedures govern how and when the meter will implement certain actions, such as resetting the demand recorder.
Open protocols and metering standards promise to ease both installation and operation of enterprise energy management systems. It will be easier for users to select new and replacement meters. Competition between manufacturers will help to reduce prices. Multiple software packages, one for each type of meter installed, will be replaced with a single package that can retrieve and perform common programming on any compliant meter.
Even with the standards, users must move with caution. Inclusion of some protocol services and most data tables is optional. Meter manufacturers have the option of selecting which portions to include in their products. They also have the option of replacing portions of the standard with their own designs, or extending the standards to enhance the performance of their products. Facility executives must carefully review how each manufacturer applies the standard to its product and how compatible it is to the facility application.
Metering systems have advanced from early generation systems that simply recorded how much energy was used. Today’s systems allow facility executives to manage their energy use and costs in a real-time format. Several key elements should be included in the system design.
First, of course, the system must provide real-time access to energy-use data. The system must be able to gather data from all facilities, including buildings located at remote sites. The system must be able to integrate data from a variety of metering devices automatically. And the system must be able to present the data in a usable format.
Having practically unlimited metering capability will provide no benefit if it does not meet specific facility needs. Start by determining what information is needed and how the data will be used. For example, if one goal is to reduce demand charges, then submetering must be installed at as many controllable loads as possible. That submetering will then provide information about which loads can be reduced to help control demand.
Any system must be flexible. Adherence to the ANSI standards will allow facility executives to gather data from practically any device. Those standards will also allow users to expand and collapse meter data — critical for future changes that may affect many users. For example, the standard demand interval today is 15 or 30 minutes. Flexibility under the ANSI standards will allow users to adhere to any demand interval length from one minute to 45 days.
Automated meter reading is no longer just a time-saving device to collect data for billing purposes. When coupled with an enterprise energy management system, it becomes an important tool for managing energy use and costs.
Energy Information is Valuable, But Sometimes UndervaluedAs director of operations for Insignia/ESG, a property management firm, John Jacques follows facility expenditures closely. What he has noticed over the past few years is that energy has become an increasingly important component of the firm’s expenses. He estimates energy accounts for about 33 percent of the organization’s operating expenses, in the Philadelphia region in which he operates. Insignia/ESG is not unlike other facility organizations, and Jacques is not unlike other facility executives who are saying with increasing frequency that cutting and controlling energy expenses is rising to the top of their priority list. Understanding where facility energy costs can be cut, however, requires knowing where the energy is being used. Whether it’s a property management firm, a health care facility or industrial property — to name a few — all sorts of facilities are struggling to discover how they can best understand energy use. “It’s clear to me from a client standpoint that if you can’t measure it, you can’t manage it,” says Bob Dixon, general manager of Energy Services & Solutions for Siemens Building Technologies. Jorge Lopez, former director of sales, power quality and reliability for Chevron Energy Solutions, an energy service company (ESCO), says while many facility executives have been given the responsibility for energy, or even an energy manager’s title, they typically don’t have the background to understand the intricacies of monitoring and making sense of energy information. “They become the ones that have to gather the information and put together the reports,” he says. “Where they fail in their responsibility is in being able to take the data and actually make some strategic decisions from it.” One obstacle facility executives face is realizing that there’s more involved with energy information gathering than just knowing how many kilowatts are used at any given time of day, says Louis Buck, chief financial officer of ConEdison Solutions, an ESCO. “Most don’t connect smart metering equipment properly and don’t run the data through a data processing facility where energy is their core competency,” he says. “We have found that the typical installation can, without spending a single capital dollar, pay back the information costs — the cost of the analysis — in two, three or four months. That’s just from adjustments made from seeing how facilities are operating to how you think they’re operating.” Despite the cost benefits of energy information gathering and analysis, facility executives and ESCOs haven’t always viewed the value of such information from the same perspective. Mara LaVoice, marketing manager for Greentech Energy Services, an ESCO, says very few customers are interested in paying for information. Even though there is a cost to the ESCO for gathering the data, facility executives have traditionally been unwilling to pay for the information upfront. “Industrial customers won’t invest in a lot,” says Mike King of Black & Veatch’s Energy Service Division. “They’re pretty tough out there.” Given the cost-saving measures that facilities can employ once they understand how their facilities use energy, some facility executives are beginning to change their perspective on information costs. “I would personally view that information-gathering function the same as I do preconstruction planning,” says John Sattelmayer, vice president of facilities for Horizon Bay, which operates retirement living centers. “I know there’s going to be a cost to preconstruction. There’s a cost for me to do it. If I treat it that way, even if I don’t do the project, I’ve got the data.”
Mike Lobash |
Rrotocol Standards Put Meter Data on Internet, LANsANSI protocol standards cover a wide range of components and applications. The strength of the standard protocols is data handling. The protocols define a set of standard tables and procedures that controls practically everything concerning the operation of the metering system. The ANSI standards are continuing to evolve. New standards will be introduced and existing standards modified to support evolving technologies in both the IT and telecommunications fields. Similarly, new standards will address issues of data security by defining encryption techniques. |
James Piper, PE, PhD., is a consultant and writer with 25 years of experience in the facilities field.
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