Services & Maintenance: Energy Management 101
By Anthony Tisot
Published in the May 2004 issue of Today’s Facility Manager
It’s becoming more challenging for companies with multiple and expansive buildings to find the funds for facility upgrades and expansion, but in many cases, an untapped source of revenue exists in the way of improved energy management practices. Across North America, companies are deploying energy management technology to help reduce electricity bills and avoid costly power quality related interruptions.
By their very nature, large corporate campuses have much to gain from managing their energy wisely. Characterized by multiple buildings, thousands of employees, and a diverse range of power requirements, a typical campus is a large energy consumer that can benefit considerably by controlling the cost, quality, and reliability of its power.
Fortunately, technology offers many ways to do that. Instead of waiting for the monthly electricity bill to determine power usage, facility professionals can now use an enterprise energy management (EEM) system to manage campus wide energy use, improve problem response, and increase reliability.
An EEM system can help managers predict energy usage for the month, allocate costs by department, and identify waste or trouble spots. A detailed understanding of the facility’s energy requirements over time can also help simulate alternative rate structures, negotiate better power supply contracts, and evaluate future options, such as installing on-campus generation.
Components Of An EEM System
A typical system consists of a network of intelligent energy meters linked to a centrally located server running the EEM software. Each meter monitors a specific location or activity, while the head end software continuously retrieves, aggregates, and processes the information.
The system logs the information in a database, responds to any alarm conditions by relaying notifications to operations personnel, and displays the real time status of each monitored area on the screens of one or more networked work stations. In short, the software aggregates and analyzes data from multiple sources and acts as the central intelligence for the entire system.
The type and location of each meter is determined by the electrical system itself. For example, an advanced, utility grade meter can be installed at the main substation to verify the quantity and quality of power delivered to the campus. Simpler sub metering devices can then be installed at key points around the campus to monitor individual buildings or departments.
Typically, the distributed meters communicate with the head end software across the campus’ existing Ethernet-based local area network; however, if the campus is geographically dispersed over great distances, then telephone, wireless, and even the Internet can be used. In some cases, the meters can use e-mail to send system updates or alarm notifications directly to the facility executive or even host a built-in Web page accessible over any standard Web browser.
Controlling Energy Costs
Although the cost of electricity is a considerable line item on most income statements, it often goes unchallenged and unmanaged. Any large business needs to take active charge of its energy management and procurement; however, to do so requires a full understanding of ongoing energy needs and the ability to manage its use.
Relatively few institutions have the ability to verify the billing statements from their energy suppliers or to allocate the appropriate amounts to specific cost centers or activities within their operations. An EEM system delivers the information needed to represent the true cost of doing business and helps to identify procedures or departments that exhibit energy inefficiencies or waste.
With a high accuracy meter located at the utility service entrance, an EEM system can monitor facility energy consumption. Automated reports can then help to verify utility bills and identify any over billing errors.
By allocating energy costs by department and using automated reports and alarm options to keep staff aware, an EEM system can help everyone actively reduce energy consumption, increase efficiency, and minimize costs within their individual departments.
With a network of meters reporting to one or more energy management work stations, facility managers have the tools to identify and monitor energy requirements across the entire campus. This information can then be presented as a load profile—basically a snapshot of energy consumption at all monitored locations throughout a typical day, week, or month.
A load profile can help to illustrate how energy is used throughout the facility, providing a baseline that can help identify inefficiencies and evaluate improvement efforts. With an accurate understanding of energy consumption, facility professionals can normalize usage patterns in conjunction with variables such as occupancy, temperature, and weather to benchmark and project energy requirements accurately.
An EEM system also helps managers analyze historical energy trends to predict needs. With this information, “what if” scenarios can be developed to help facility managers optimize loads or processes and even negotiate better energy contracts. Accurate information on usage trends can also help discover unused capacity, which in turn can defer capital investment decisions such as building additional on-site generation.
Depending on the campus location, there may also be an opportunity to take advantage of demand response or load curtailment programs offered by energy suppliers. These programs offer price concessions to the consumer in return for a load reduction agreement from the customer. (The consumer will be expected to reduce its load any time energy consumption across the power grid is at a critical peak.) In this way, the consumer can also avoid incurring penalties from the utility for exceeding a maximum power demand level during peak times.
When energy prices are high or demand is rising too quickly, an EEM system can start a generator or dynamically shed non-essential loads (such as heating or air conditioning) to reduce the energy drawn from the utility. And because utilities may also bill an additional surcharge for consuming energy inefficiently, an EEM system can intelligently control capacitor banks to correct low power factors and again avoid penalties.
Maintaining Power Quality And Reliability
When it comes to power quality, the cost of harmonics, sags, transients, and outages can quickly become very expensive. Data may be lost, equipment damaged, and procedures interrupted.
Power quality is especially critical for the types of sensitive applications found in data centers, science labs, and medical facilities. With sensitive equipment requiring clean power, these operations require near 100% uptime.
The power grid was designed to deliver “three nines” of clean, reliable power; that is, it provides a constant flow of energy 99.9% of the time. Although this is sufficient for lighting and motor loads, new digital assets and processes may require power reliability as high as “six nines” (99.9999%) or higher.
To achieve this, a company may have one or more feeds from the utility or some form of stand by generation with a transfer switch that selects between the utility and the generator feed. However, because generators typically cannot start up instantly when needed, other forms of mitigation equipment, such as UPS/battery systems and flywheels are used to fill in during the interim. These are connected by electrical distribution equipment such as transformers and circuit breakers.
In facilities where research is being conducted, a single interruption can easily result in the loss of months of costly work. To help offset this risk, on-site generators are becoming a popular addition, but the opportunities they provide can also raise many questions. As a source of stand by power, generators can not only support improved reliability, but can cut costs by “peak shaving” during busy demand times, and can convert waste heat to electricity through cogeneration.
A clear understanding of generator processes is crucial to the efficient and economical operation of the facility. For this reason, an EEM system can provide a simple and efficient way to manage on-site generation assets by profiling energy requirements and managing generators or loads based on power reliability or economic conditions.
When power quality fluctuations are suspected, portable power monitoring equipment can sometimes help to pinpoint problem areas. However, when looking at a large facility setting, an EEM system with its network of permanent mount meters installed at key locations can verify power quality around the clock. This solution combines fast desktop access to status information for the entire electrical system with the ability to receive early warning alarms anywhere.
And like the flight recorders used by the airline industry in planes, the EEM system provides valuable forensic data after an event. This may help personnel identify the source of a disturbance and take corrective action to help prevent a reoccurrence. Detailed power quality reports can also help personnel correlate poor power quality with negative impacts on operations and processes.
When considering the pros and cons of an EEM system, facility professionals should start with a clear understanding of energy usage across their corporate campuses over a given period of time. From there, assessments can be made based on fact, corrective measures can be identified, and the relative success of improvements can be verified. By supporting a continuous cycle of research, optimization, and verification, an investment in energy management strategies can open the door to a more efficient and cost-effective future.
Tisot is a professional writer with Power Measurement, a Saanichton, BC-based company that specializes in energy management strategies and communications technology.
Topic Tags: Power Measurement