Building Management Group Finds Financial Benefit in ComEd's EnergyTracker Program

The days of unenlightened service from electric utilities are drawing to a close. The prospect of utilities and other electricity distributors actually competing for customer dollars has shocked an industry accustomed to being the only game in town. When they finally arrive on the scene, upstarts will no doubt try to compete on price, with the result that large energy consumers—once the ace in the hole for power companies—may start to view electricity as a commodity, switching from provider to provider as easily as some people switch phone companies.

Smart utilities have already begun the battle for customer loyalty, finding ways to pare the cost of electricity while adding the kind of value and service that customers don't walk away from: good news indeed for the consumer.

 The Cooperative Approach

In Chicago, we've seen Commonwealth Edison refine a program, initially focused on its own needs, into a mature, market-driven operation that provides consumer benefits beyond kilowatt-hour costs.

ComEd's operational strategy focused on curtailing power demand in order to avoid the expense of building new power plants One element entailed working with large commercial, institutional and industrial businesses on a voluntary basis. Local companies like Sears, Motorola, the Equitable, Montgomery Ward, and the Richard J. Daley Center joined ComEd's Energy Cooperative to manage power consumption during crucial summer periods of peak demand.

 In addition to the desirable "load management" capability, ComEd also wanted to be able to incorporate various power quality products and services as an extra capability they could provide to their customers.

 While other utilities have used similar "demand side management" programs, most have imposed their own load interruption demands. In Chicago the utility worked with each cooperative member to establish a customized load-reduction strategy and practical commitment level. For instance, one member might shut down perimeter lighting in work or common areas; another might idle an elevator bank or cycle air conditioning equipment. All members agreed to reduce demand within an hour of notification. In exchange, ComEd paid members a rebate according to average load reductions.

The Drive to Add Value

 In the beginning, each co-op member received a PC-based link to utility revenue meters. These PCs created a bar chart that showed power usage. Although users were able to monitor demand, functionality was limited. Building and plant engineers had little control over their power bill and no way of monitoring power reliability and quality. Members let the utility know that they wanted more out of the system.

Co-op members found a sympathetic ear, and last year ComEd's Stephen Szumski, who manages ComEd's Energy Cooperative, brought the Siemens' ACCESS Power Monitoring and Control System to all member facilities. Suddenly, co-op members were on a system that offered a great deal of end-user benefits. Siemens' software provides a graphical user interface for viewing and reporting, in real-time as well as historical perspective: minimums and maximums; power quality data; trending; and event logging. The ACCESS system can tie into a variety of remote field devices, including power meters, switchgear, trip units, and protective relays, for even more data.

In addition to early system problem identification, the new system gives cooperative members the greater functionality they wanted, potentially to allocate power usage cost, verify utility bills, and identify and control peak demand. To this basic system can be added the necessary components such that customers can monitor and analyze power quality data including harmonics and disturbances anywhere on their power systems. The ability of a multi-user facility such as an office building to allocate energy costs according to actual power usage rather than square footage or head count was highly appealing to some members.

The new 'EnergyTracker' system connects every ComEd revenue meter that measures a curtailable load with a pulse reading meter (PRM) — a self-contained micro PLC (programmable logic controller) with its own power supply, digital I/O and serial output. The PRM reads the pulse output of the revenue meter and calculates the demand and kW usage. It also keeps a historical log file of the kW demand and relays it to the on-site computer, which tracks an average of half a dozen meters per site in the co-op. To this basic system can be added meters and relays which have the capability to do "waveform capture", resulting in a harmonic analysis, and "waveform recording", giving the end users disturbance analysis information concerning voltage sags and sways and relay pickup and trip events.

For the purposes of the summertime curtailment program, an alarm box was supplied that sounds whenever a curtailment is announced (in addition to a pop-up on the screen). Switching off the alarm acknowledges that the call has been received.

Realizing the Full Potential

Co-op members realized the potential the new system held. They began using the energy monitoring system to isolate peaks, and then worked backwards to the meters and then to the equipment that caused those peaks. They were then able to review options that would lead to reducing peak loads.

One example of end-user benefits is found at 77 W. Wacker Drive, a 50-story, Class Triple-A office tower in downtown Chicago and the headquarters of RR Donnelley & Sons. Tenants here expect to maintain a certain comfort level, especially during the summer. It was a challenge for us to find ways of reducing load while not inconveniencing the tenants. Eventually, we turned off some lights in the main lobby and shut off or cycled other equipment. For instance, we idled one elevator in each of the three banks.

To bring the tenants on board, we have used our quarterly newsletter to quantify the savings to them in kWh, and tied that in to our ongoing waste recycling program: "It's good for Chicago, it's good for the environment, and it helps us all." This message was reinforced by the ComEd rebate payments, which tangibly reduced truant occupancy costs.

When ComEd notified us about a scheduled curtailment, which might range in duration from two to the full six hour commitment, we made sure that the tenants were not adversely affected. We soon discovered the best approach was simply to lower the standard pressure on the fans to use less power. We also let hot water temperatures drop from 105 degrees to 90. We have never received a tenant complaint. In fact, the only way tenants might know that a curtailment is in progress is that the main lobby is slightly darker than usual.

The incentives for building management to participate in the curtailment program were energy conservation, goodwill with the tenants, and of course, the ComEd payments. But the greatest savings came from managing energy consumption by using the ACCESS system analysis capabilities. Each meter can be displayed and broken down on a spreadsheet against 30-minute demand, thereby enabling us to stay within or even to reduce ComEd's time-of-day/demand billing guidelines that determine customer rates.

 As we became familiar with operating the system, we learned to connect it with the Building Automation System that controls the fans, chillers, the main power and mechanical equipment. The ACCESS system has the capability of compiling a memory of the building's operations, of knowing exactly when it can turn on a motor to meet set points while taking into account the demand factor.

  Our long-term objective is to run the building with the most efficient use of energy possible. The Chicago real estate environment is highly competitive, so watching costs is a crucial management function. With automation, we've taken preemptive action to shave off those all-important usage peaks that the utility company uses to determine our rate of billing. We estimate that already we have lowered our electricity bills by 15% annually, and we project this reduction to eventually reach 30%.

Saving $100,000

 Production facilities as well as office buildings have experienced appreciable benefits using the ComEd system. Just ask Dennis Cleary, Aseptic Supervisor at Chicago's McCain Citrus Inc., home of the BoKu brand of drinks. "Our main purpose in using this PC, over and above responding to ComEd's curtailments, is to manage our load and especially to control our demand," he says. "We have fluctuating demands from the four compressors we use to keep our 1 million cu. ft. freezer at 24 degrees below zero.

 "During the summer, when the loading bay doors are left open, all four compressors kick in, and that creates a heavy demand. Fortunately, the PRMs can figure out demand instantaneously, so we set alarms for an instantaneous kW level before the fourth compressor kicks in. When the pop-up window comes on, we close the doors before we set a new peak.

"When we curtail, we shut down our 800 kW transformer in the engine room, which supplies all the compressors for the freezer. After five-to-six hours, the freezer rises from minus 24 to minus 14 degrees, so we are still within safety parameters.

 "We also use the alarms on the system to monitor the unmanned engine room. If we have a failure, a pop up alarm appears on the screen. ComEd has certainly added value to the service they deliver with this system: I estimate we have saved $100,000 in electricity bills over the last three years, mainly as a result of utility payouts and reduced usage.

"The system has potential for further value. The long time pick-up data, for instance, will allow us to look into and fix overloads before they create outages and lost production."

Adding Still More Value

Some members still view the system as a glorified meter reader, not realizing the wide range of analysis tools available to them that can save them even more money.

 Both ComEd and Siemens are working to educate end users on the different metering and hardware products, field gear, motor protection devices and other components that the ACCESS system comprises. The more users know about the system, the more they can do for themselves. They can, for instance, analyze and take steps to control power quality to avoid undervoltage conditions in one area without creating problems in another.

Users are now able to have sophisticated meters and relays with built-in power quality capability supplied on new electrical distribution equipment. They can also easily retrofit existing distribution systems with these same components. The difference between these kinds of devices and traditional "disturbance analyzers" are both technical and financial. While the capability of meters and relays used extensively on a day-to-day basis is not as great as what some might consider available from a fault recording device, the meters and relays have to be used in the power system anyway, for reasons involving protection and system design. Since these devices have to be present anyway, their additional capability for power quality data is essentially free.

Traditional fault recorders have been expensive portable devices, and must be moved to where a problem is believed to be, in hopes that it will be repetitive. Using meters and relays that will be in place all the time, faults and other power quality phenomena can be determined as soon as they occur, not after the fact. The data that is available from these devices includes both harmonic and transient information, and can be used by power system engineers to make recommendations which would minimize possible thermal damage from harmonics, or pinpoint the location and cause of dangerous faults, eliminating them in the future. From this data, engineers can make recommendations regarding the application of harmonic filters, or modified protection schemes to more reliably protect plant and personnel. Both harmonic and disturbance information will be used in the future to objectively rate power delivery by electrical distribution companies competing for end user business.

Customers who have their own transformers will be able to assess the exact load on each and then know whether they have enough capacity for expansion. At the moment, plants only know the total load of all transformers and so they typically add another one at great expense because they can't risk creating overloads.

Timely maintenance of equipment is a real system bonus: The power monitoring and control system can help determine which loads warrant maintenance (through its monitoring and recording of equipment usage) and therefore reduce downtime and maintenance costs. It allows proactive maintenance as opposed to a shotgun, gut-feeling approach to maintenance.

The system is invaluable for crisis management. It can isolate the cause of an outage immediately and help the building or plant return rapidly to normal operation. The appreciable benefits of the current system may soon be augmented by future developments. ComEd is taking the "EnergyTracker" concept further by designing a product that links its rates structure with data from meters so that customers can estimate their bills on-the-fly.