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The POWER of MONITORING

By Loren Snyder - October 2002 - Power & Communication


Energy deregulation efforts in dozens of states have slowed during the last several years, hampered by the debacle in California and the fall of energy giant Enron. So it seems reasonable to expect that subsequent efforts to contain and control energy costs in commercial and institutional facilities also might have slowed.

But while deregulation of electric markets created much of the initial impetus for maintenance and engineering managers to meter facility energy use, interest in metering and monitoring technology continues unabated in many institutions.

Put simply, the use of monitoring and metering equipment allows much more than demand reduction or cost containment; modern measurement devices help managers do more than simply meet their utilities’ curtailment requests.

Consequently, a growing number of managers are investigating – and reaping – the benefits gained from installing metering equipment.

Needs Assessment

The array of meters on the market can be dizzying. And an individual meter’s portfolio of capabilities can overwhelm managers not intimately familiar with electrical lexicon.

That is why managers need to first assess their facilities’ needs, says Lindsay Audin, once the energy manager for Columbia University and now the president of Energywiz, a energy consulting firm.

To narrow technology choices, managers first must determine an institution’s data needs. For instance, will the metering equipment measure power quality and prevent disruption, consolidate billing requirements, forecast energy use, contain costs, or meet utility curtailment requests?

Ultimately, large-scale energy buyers need to specify metering equipment that includes time-of-day and real-time pricing capabilities, Audin says.

“You need the best meters,” he says. “We’re talking industrial-grade meters with the necessary ports for software downloads and 15-minute measurement intervals at minimum. It’s better when managers buy top-of-the-line meters with real-time or 5-minute delays and expect them for last 20 years.”

Aurel Selezeanu, Duke University’s assistant director for electrical utilities, takes a slightly more conservative view of hardware longevity. He says he expects Duke’s recent meter purchases to last 10-15 years.

“The actual hardware will last longer than that, but in 15 years, technology will make them obsolete,” he says. “We’ll need to replace them by then.”

Networkable Solutions

The lines of distinction between energy management systems and other building technologies are blurring. Metering equipment can provide information to energy accounting software, or organizations can use it in conjunction with building automation systems.

“Managers should focus on any requirements for working with existing systems already in place, like Windows network compatibility,” Audin says. “You may not want to marry those systems now, but it's good to know you can do so later.”

Managers also need to identify any ‘extra’ metering capabilities their institutions could benefit from: Remote meter reading, automatic data entry, or pager alarms might be worthwhile investments for some institutions.

Selezeanu recently learned the importance of such capabilities. Duke University’s energy management software rang Selezeanu’s pager one night after it identified a tap-switching problem in a distribution transformer. Using his laptop at home, Selezeanu was able to download energy data and, with a call to Duke Power, clear the switch. These extra capabilities, including remote-communication abilities, can help managers avert potential power outages.

Performance Measurement

New York is one of the few states that has not pulled sharply away from deregulation. Operating in an environment that favors deregulating power utilities led Syracuse University to begin installing metering equipment in 1996, says Steve Lloyd. As Associate Energy Director at Syracuse University, Lloyd says the university used the meters to shed demand as required by the university’s utility.

“We also use the equipment to find setpoints in the system, for record-keeping, for data analysis and cost-savings,” he says. “But our ultimate goal is to forecast our daily energy usage and participate in day-ahead pricing. We want to be able to buy energy on the open market.”

Duke uses metering and energy management systems to control peak demand. Selezeanu says that the 75 meters located at substations and individual buildings on campus also monitor power quality.

“The ability to meter energy, and then run that data through the university’s energy management software, saves Duke about $1 million annually,” Selezeanu says. Data accrued from the system also gives him first-hand information about campus energy use. This kind of information frequently is valuable when he has to approach university management to seek additional equipment.

Submetering

Measuring energy use within separate institutional departments via submeters — which can be more expensive than main meters — can return significant cost benefits and govern energy management decisions. Submeters are usually located at individual buildings and give managers insight on how occupants use energy. In some cases, this knowledge helps facilities find chronic energy wasting technologies or habits and curtail unnecessary energy use. Submetering also allows managers to more fairly divide energy costs between individual departments.

“Many universities bill on a square-foot basis, which is silly,” says Audin. “A university laboratory is going to use far more power than a residence hall.”

Mohammad Qayoumi, author of a The Metering Guide for Managers and vice president for administration and finance at California State University, Northridge, agrees. In many campuses, he says, some tenants should be charged separately for their energy use.

And while submetering can be cost-intensive, Qayoumi says managers can use lower-cost meters that are non-revenue-grade and have fewer features than substation meters.

Power Quality Concerns

Both Selezeanu and Lloyd list power-quality measurement as another essential function they require in a metering system. Selezeanu says even large equipment, such as chillers, can be knocked off line by sags and swells.

More frequently, Qayoumi says, power quality issues affect sensitive equipment. The abundance of non-linear devices — including computers and certain kinds of lighting — litters distribution systems with harmonics, transients or electrical noise. Without taking adequate measures against power quality fluctuation, managers risk data corruption, computer crashes, and other potentially damaging disturbances.

Qayoumi also warns that quality concerns such as harmonics can lower power factor — a measure of energy efficiency — causing faulty meter operations or creating nuisance tripping of circuit breakers. Measuring power factor is critical when faced with utility providers who charge penalties for power factor dips, usually below 85 percent.

In short, monitoring power supplies and recording historical use puts power in managers’ hands. Not only does data on energy use empower managers with the ability to forecast future energy use when entering energy contracts, it also helps protect facilities against problem-causing power quality concerns. And in the case of Duke University, it allowed Selezeanu to take energy use data to his superiors, building a foundation and framework for future metering technology purchases.

Meters and Software:
Foundations for energy management

Meters and energy-management software form the foundation from which managers can control energy use, contain costs and monitor power quality. But meters also can measure a multitude of performance data, from high-speed waveforms to harmonic distortion levels.

Meters

Regardless of needs, main meters should be able to record:

  • current — average three-phase current or individual phases, neutral and ground current
  • voltage — individual phase-to-phase, phase-to-neutral and neutral-to-ground
  • power — real, reactive and apparent power for individual phases or the system
  • energy — real, reactive energy for net quantities. This feature is particularly helpful when in-house generation is connected to the system.
  • frequency — measured by time and date
  • demand — real power, reactive power and apparent power
  • power factor — apparent and displaced

Many mathematical and logic functions are possible with today’s metering equipment. Managers should look for those functions that best suit facility needs.

Software

Energy-management software – which is usually run on a PC – analyzes and interprets the vast quantities of data recorded by meters. Major benefits in software packages that managers should seek include:

  • Comparison of rate structures
  • Allocation of utility costs, including related charges such as taxes and power factor penalty charges. This capability also is important when facilities need to submeter separate tenants.
  • Historical data storage capabilities
  • Synchronization of all meters to utility pulse calculation of "coincidental" peak demand.
  • Processing of bill creation for internal customers, which helps alleviate the need for data entry and associated keystroke errors.
  • Utility bill verification capability.

— Adapted from Mohammad H. Qayoumi’s The Metering Guide for Managers,
published by the Association of Higher Education Facilities Officers.





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