Real-time energy monitoring systems-The missing piece in the energy efficiency puzzle

As the portfolio of smart, energy efficient buildings in the United States continues to grow in quantity and sophistication, the same inherent question remains: how are we doing? This simple question can be deceivingly difficult to answer. Picture a typical building in the northeast where multiple energy sources are being measured by multiple meters with potentially multiple utility and commodity providers. If the building staff is able to obtain pertinent information from all of these data sources, the result is twelve readings for a years' worth of energy consumption. Twelve data points is adequate when performing an annual benchmarking report, but that is far too little to infer any significant information about the building, let alone answer the simple question: how are we doing? Benefits Real-time energy monitoring systems serve to answer the question, "how are we doing?" It is often the missing piece in energy efficiency and renewable energy projects. Real-time monitoring also allows staff to identify and correct problems that lead to abnormally high consumption, reducing the risk of receiving "surprise" utility bills that are outrageously expensive. In addition, real-time monitoring portrays energy consumption in a way that occupants have never seen before, raising awareness throughout the building. Savings can be obtained simply from greater occupant awareness in the building. The system provides a level of energy savings insurance, which is highly beneficial for buildings participating in energy incentives programs that provide funding based on actual savings. Programs such as Pay for Performance in New Jersey or the NYSERDA Multifamily Performance Program allocate portions of their incentives on verified energy savings. Monitoring systems are also appealing to ESCOs and private financers who want guaranteed savings. An outside air sensor can be included to provide results that are normalized based on local weather. Variance in the local weather can have a significant impact on performance results and should be accounted for when measuring and calculating building performance. Weather-normalized results can provide the building staff with insight as to why your building may have used more energy than normal over a specific time period. System Components The components included in an energy monitoring system will depend on the building's metering configuration and electric distribution equipment. The graphic shown is an example of what a typical energy monitoring system entails. Direct tenant metered buildings will have a different configuration with a power meter connected directly to the main electric distribution equipment. All systems must have a way to measure incoming power and fuel at the utility meters. This is typically done with a pulse initiator, a simple device that provides a dry contact closure after a specified unit of energy has been measured by the meter. Pulses are read and stored by a pulse logger. Similar to a car odometer, the pulse logger serves as the principal device for tracking the building's total energy consumption. Information from the pulse logger can be sent to a computer to perform analytics on historical performance, future projections and answer the "how are we doing" question. If the computer is connected to the Internet, results can be displayed over a web page for remote monitoring. Case Study - The Falcon Group HQ, Bridgewater, N.J. The Falcon Group utilized the headquarters office in Bridgewater, NJ to develop low-cost energy monitoring system. The system provides minute by minute electric and natural gas data and projects hourly, daily, monthly and annual energy costs and consumption. The performance of the building is tracked in real-time using preprogrammed, static factors such as the building's baseline energy consumption and equipment. Dynamic factors such as weather are used to adjust the savings totals and performance figures. The system can be viewed on a web page with simple text descriptions of the past, present and projected performance of the building. The page also prioritizes the building based on energy consumption and annual trends. This allows for facilities staff to quickly prioritize their tasks. The Falcon energy monitoring system aided in optimizing the set points and equipment schedule for each thermostat in the building. This aided in improving the efficiency of the equipment while simultaneously improving occupant comfort. The building has maintained an Energy Star rating of 90 or above since its construction in 2006. Getting Started To get started, your association should have an engineer inspect the metering and power distribution equipment in the building. The engineer will determine the required system components based on their findings and layout the steps to move forward. Systems with pulse initiators will require involvement with your local utility provider. It is recommended that utility work orders are placed well in advance of the anticipated installation date. Should the association decide to get Internet connectivity to their system, it is recommended that any work required by your Internet service provider is also completed before installation begins. Putting it all Together Real-time energy monitoring serves as the missing piece in the energy efficiency puzzle, answering the question, "how are we doing?" Utility bills often give an incomplete or inaccurate picture of a building's performance, leaving the building staff to deal with estimated readings and missing data. Energy monitoring systems will become more of a necessity as more private financers move into the energy efficiency and renewable energy projects. These systems also provide assistance with measurement and verification of the energy savings, a key part of many state and local incentives programs. Casey Birmingham is a project manager/energy and MEP at The Falcon Group, Bridgewater, N.J.