Payback and Process- Energy Monitoring Payback
- 1. What to Monitor Monitoring of total electrical consumption and sometimes key load centers provides important data that can be analyzed to give key cost reduction information. Guidelines from the DOE and similar sources recommend using “live” or “real-time” data for reporting and analysis. Automated alerting and real-time cost analysis are extended benefits that enable decisive, cost reduction actions. Monitoring Benefits Reduced energy costs and reduced energy demands on the power grid are the foundational benefits. Monitoring also provides the ability to verify efficiency improvements, effectively reduce loads, calculate the ideal tariff schedule and verify billing accuracy. Monitoring Payback Direct Payback Indirect Payback Operations Tariff & Usage Energy Profiling 1 to 3% 2.5 to 4.5% 15 to 40% Changes in operational behavior Business Process Changes Tariff schedule changes Billing Corrections *Peak demand corrective action Energy reduction projects Facility improvement measures There is direct and indirect payback from energy monitoring. Direct payback is received from changes in organizational behavior and business process and represents 1 to 3% of immediate payback. Indirect payback is comprised of two components; tariff & usage involving tariff schedule, billing and peak demand corrections, and load profiling to identify energy reduction measures. The payback amount is dependent on monitoring key variables e.g. type of load, load profile, tariff schedule, and peak usage; variables which cannot be identified without monitoring. Reductions of 2.5 to 4.5% come from tariff and billing corrections and are considerably higher when peak demand charges are levied; where 15 to 40% reduction gains can be accomplished through load profile identification and follow on facility improvements. Paybacks on single source monitoring generally range from 8 to 20 months. Payback is maximized when combined with energy analysis and when definitive reduction energy use habits and load shifting/sharing processes are employed. Below is the monitoring payback analysis for your review. Real Life Monitoring Cases Private School A private school experiences the high energy costs, particularly from demand charges. ACTION: Energy monitoring is installed and demand peaks are found to occur early morning. Real-time analysis determines that that electric classroom heaters are being turned on simultaneously and causing a 30-45 min spike in electric demand. Programmable thermostats are installed and set to provide a staggered heater operation during early morning hours. Monitoring confirms the expected drop in peak demand. RESULTS: Classrooms are pre-warmed, demand charges drop 50%, energy costs are reduced by >20%, System payback 12 mo. Food Manufacturing Plant A specialty food manufacturing facility seeks to improve the bottom line by cutting energy costs. ACTION: Energy monitoring with cost analysis is installed on the main meter and key load centers. Cost profiles identify two large refrigeration units with high energy consumption and high demand. Multiple energy efficiency technologies are employed to reduce consumption and demand. RESULTS: Energy consumption and demand decreases are verified and documented using energy monitoring data which isolates benefits derived from each of the different technologies. Utility company issues rebate based on monitoring system reports. Rebate amount covers 1/3 of project cost. Payback for customer is less than 24 months, including the cost of monitoring. Customer now monitors performance of units in real-time and is alerted when energy consumption exceeds preset limits. RULES OF THUMB FOR EFFECTIVE MONITORING Record historical data from the past 24 months at least. Ensure measurements are accurate enough to be useful, use revenue grade meters when possible Ensure recordings are regular and frequent enough to pick up any relevant highs and lows Plot the ratio of peak and off-peak electricity, and peak demand Plot actual versus charged demand (electricity). Record associated data simultaneously for comparison Consider monitoring large use items individually Install sub-meters to measure energy use by areas with separate accountability. Monitor in real time and use alarm set points to alert staff that presets have been exceeded BENEFITS OF MONITORING ENERGY Gives better information for analysis of energy consumption. Provides technical and financial information needed to make strategic decisions regarding operating activities. Identifies inconsistencies in operating and shutdown procedure. Utility billing accuracy, and levelizing of solar once/year billing offsets. Better information for analysis of energy consumption and performance improvement trends Information to justify and support a strategy for achieving improvements through target setting, and development of Energy Benchmarks Impartial and accurate reporting, which enables senior management to assess and control energy consumption and costs. Energy Monitoring Payback