Presentation on theme: "ENPM808W Energy Efficiency/Energy Audit and Conservation Week III, Lecture 1: Energy Audit Procedures and Energy Benchmarking Dr. Michael Ohadi Spring."— Presentation transcript:
ENPM808W Energy Efficiency/Energy Audit and Conservation Week III, Lecture 1: Energy Audit Procedures and Energy Benchmarking Dr. Michael Ohadi Spring 2015
2ENPM 808W: Advanced Energy Audit Energy Auditing Energy audit is part of the overall energy program Audit: official examination and verification of accounts and records Energy audit tasks per ASHRAE: Collect and analyze historical energy use Study the building and its operational characteristics Identify potential modifications that will reduce the energy use and cost Perform an engineering analysis of the modifications Prepare a rank-ordered list of modifications Prepare a report to document the analysis process and the results
3ENPM 808W: Advanced Energy Audit ASHRAE Commercial Building Energy Audit Levels Three Levels ASHRAE Level 1: Walk-Through Analysis ASHRAE Level 2: Energy Survey and Analysis ASHRAE Level 3: Detailed Analysis of Capital Intensive Modifications
4ENPM 808W: Advanced Energy Audit ASHRAE Level 1 Analysis Walk-through analysis Analyze energy bills Conduct a brief on-site visit Brief survey of the building characteristics and occupants Recommendations on low-cost/no-cost improvements Preliminary Identification of Capital Improvements
5ENPM 808W: Advanced Energy Audit ASHRAE Level 2 Analysis Energy survey and engineering analysis Analyze energy bills in more detail More detailed building survey Breakdown of energy use within the building Review operational and maintenance procedures Provide savings and cost analysis of all practical improvements Provide a list of potential capital-intensive improvements
6ENPM 808W: Advanced Energy Audit ASHRAE Level 3 Analysis Detailed analysis of capital-intensive modifications Very detailed building survey Detailed review of operational and maintenance procedures Detailed building modeling/simulation (Transys, EnergyPlus) with validation from data gathering Focus on analyzing potential capital-intensive modifications Provide detailed project cost and savings calculations with a high level of confidence Obtain actual contractor pricing if possible
7ENPM 808W: Advanced Energy Audit Energy Audit Procedures Pre site visit Information gathering Site visit Building Survey Post site visit Calculate energy savings and generate report
8ENPM 808W: Advanced Energy Audit Pre Site Visit Obtain review Mechanical, Electrical, Lighting and Plumbing Drawings Obtain Floor plans Obtain basic facility physical information Building area (SQFT), year built, types of utilities Weather information Perform a Utility Analysis Calculate EUI (Energy Utility Index) for Benchmarking
9ENPM 808W: Advanced Energy Audit Site Visit Survey mechanical, electrical and lighting systems Envelope Lighting HVAC Domestic Hot Water Laundry Food Preparation Conveying Systems and Other Identify Energy Conservation Measures Gather related information such as equipment name plate information, motor efficiencies, lighting measurements etc.
10ENPM 808W: Advanced Energy Audit Post Site Visit Energy Savings and Payback Calculations Energy Conservation Measures List assumptions Provide basic methodology of the calculations – May be asked to provide more details Results Report findings including cost and payback Provide reasonable cost estimates Typically expected to be within ±20% for ASHRAE Level 2 Payback calculations Simple payback = Cost / Savings Complex (based on time value of money, inflation, depreciation, before and after tax considerations) Recommendations
11ENPM 808W: Advanced Energy Audit Energy Benchmarking Utility Analysis Collect and review minimum 1 year of utility data Electric, gas, steam, propane, oil, chilled water, etc. Graph consumption and cost data – Energy load profile, Demand, Load Factor Look for seasonal patterns and anomalies Energy Benchmarking: Important part of ASHRAE Audit Procedure Calculate Energy Utilization Index (EUI): kBtu/ft² Cost Index: $/ft²
12ENPM 808W: Advanced Energy Audit Energy Utilization Index (EUI): kBtu/ft² EUI = Total Energy Consumption of the building divided by the total building area Site EUI The Btu value of energy is measured at the point it enters the building Source EUI (Primary Energy Consumption Index) The Btu value is equal to site energy plus losses that occur in the generation, transmission, and distribution of energy Incorporates inefficiencies at the power plants, transmission and distribution lines etc. Source EUI Varies regionally due to the diversity of fuel sources utilized in the power plants. Average values used under consensus.
13ENPM 808W: Advanced Energy Audit Site Energy Utilization Index (EUI): kBtu/ft² Total Energy Consumption of the building divided by the total building area Example: An Office Complex in Landover, MD 345,065 ft² Annual Electricity Consumption: 5,145,874 kWh – x3.413 kBtu/kWh = 17,562,868 kBtu Annual Natural Gas Consumption:158,100 Therms – x100 kBtu/ Therm = 15,810,000 kBtu EUI = 96.7 kBtu / ft²
14ENPM 808W: Advanced Energy Audit Forms of Energy Utilization Index (EUI) Energy/Productivity Indicator AdvantagesDisadvantages Btu/ft 2 -Concise. Most commonly used. -Accurate when process energy is low or constant and weather is consistent. -Very consistent (easy to measure sq feet). -No measure of production. -Doesn’t account for weather -Assumes energy is linear with floor space. Btu/unit of production-Concise. -Accurate when process energy dominates. -Appropriate for comparing plants with similar production profiles. -Difficult to measure “units of production”. -Doesn’t capture high HVAC and/or lighting contributions. Btu/degree day-Concise. -Accurate when HVAC system energy dominates. -Consistent between similar structures/plants (easy to measure or obtain degree day data). -Disregards production energy and process needs. -Buildings with large thermal mass don’t respond as quickly to degree days. Btu/unit-degree day-ft 2 or Btu/unit-degree day -Captures several variables. -Somewhat consistent and more accurate than the above measures. -Can capture a very specific need. -More complicated. -More difficult to comprehend. Btu/sales dollar or Cost of energy/$ sales or $ profit -Easy to compute. -Relates energy consumption to profitability. -Demonstrates $ results, not just conservation. -Does not account for inflation. -Difficult to account for all variables that influence profitability. Btu/direct labor-Similar to a measure of production. -Easy to get accurate data. -Good when process energy is the dominant energy. -Consistent across plants and possibly industries. -Energy is often not linearly proportional to labor costs. -Does not account for high HVAC/lighting demands.
15ENPM 808W: Advanced Energy Audit How to compare EUI between different buildings? U.S. D.O.E. Energy Information Administration provides statistical data http://www.eia.doe.gov Databases for Energy Intensity Residential Commercial Buildings Manufacturing Industries Experience!
16ENPM 808W: Advanced Energy Audit U.S. Commercial Buildings Energy Intensity
17ENPM 808W: Advanced Energy Audit Energy Star Portfolio Manager for energy benchmarking Free benchmarking tool by EPA and DOE Interactive energy management tool that allows tracking and assessing energy and water consumption Manage Energy and Water Consumption for all Buildings Rate Building Energy Performance Estimate Carbon Footprint Set Investment Priorities Verify and Track Progress of Improvement Projects Gain EPA Recognition Improve property value => High profile tenants
18ENPM 808W: Advanced Energy Audit https://www.energystar.gov/istar/pmpam/index.cfm https://www.energystar.gov/istar/pmpam/index.cfm Create online account Add new facility Define space use types Add energy consumption data Enter energy bills directly Obtain energy star score and interpret results Energy Star 50 = Average Building Energy Star 75 = Energy Star Certified Building Requires to be a Licensed Professional Engineer (PE) to certify Track monthly changes with the score Energy Star Portfolio Manager How does it work?