Energy Audits in Kuwait (case study of The Public Authority Applied for Education and Training (PAAET))

Transcription

1 International Journal of Latest Technology in Engineering & Management (IJLTEM) ISSN: Energy Audits in Kuwait (case study of The Public Authority Applied for Education and Training (PAAET)) ABSTRACT In the ex-socialist countries governments plan to promote energy audits. The ways and the forms of the promotion are not yet clear. However, there is an urgent need for energy audit practices and procedures. How is this energy audit guide targeted? Because the financial opportunities of the governments differ and the governments have different plans to develop their energy audit schemes, the objective of this energy audit guide should be on the method side. The guide will show the main principles and the main approaches of energy auditing and how the thoroughness of an energy audit affects the procedures and methods of the energy audit. These ge neral outlines on energy audits can be applied when energy audits are promoted. By reading this guide no one will become a qualified energy auditor. Hopefully, this guide will show what one must do to become one. In the ex-socialist countries, the main energy saving potential exists in the buildings built according to the ways and procedures of the socialist period. Key Words: Energy Audit, Preliminary Energy-use Analysis, Energy Cost Index. INTRODUCTION Energy audit is a term used worldwide. As with all terms, the definition and the content of an energy audit differs from person to person and from society to society. In many countries like in Finland, governments subsidies energy audits. In some countries, the law may require that energy audits are carried out at regular intervals. In both cases, governments may require that energy audits are carried out in accordance with some form or regulation for obvious reasons. These regulations tend to differ from country to country. For example, in Finland there are some six different kinds of energy audit models. This diversity of models is mostly to rationalize the decisions concerning the subsidies for energy audits and to develop and control the work of auditors. Energy audits for buildings and industry should have a different emphasis. If the same subsidy scheme is applied for a school and for a paper mill, it is difficult to have a fare subsidy policy. However, the main principles of energy audits are applicable to both types of targets. In the building sector, domestic water use and its saving opportunities are normally seen as a part of energy audits. When the phrase energy audit or energy in a general sense is used in this guide it includes both energy - fuels, heat and electricity - and water. 1.1 Definition of energy audit Although there are many models for energy audits, we can give some common definitions for an energy audit. We can define the main idea of an energy audit very simply: It is a procedure to show how energy is used in an audited target, and what are the measures to save energy or to improve energy efficiency in the target. The scope and thoroughness of an energy audit depends on the audit model applied and on the available human and financial resources. METHODOLOGY The energy auditing (EA) procedure consists of three main phases that could be done all together as one program or as single separated phases depending on the budget and the team size.in addition to the three main phases to the EA, a preliminary Energy-Use Analysis (PEA) is done, which is a perquisite for any audit, which do not, and there are targeted audits, which do not have strictly defined level of effort but may be useful or necessary for some situations. 2.1 Preliminary Energy-Use Analysis (PEA) The PEA proceeds an audit of the building. During PEA analyst analyze the historic utility use, peak demand, and cost; develops the Energy Cost Index (ECI) of the building (expressed Dinar per floor area per year); and develops Volume 2 Issue 2 page 14

2 the Energy Utilization Index (EUI) of the building, (expressed in kbtu/ft 2 [MJ/ ] per year). The analyst then compares the building EUI to similar building EUI s to assess the potential for improved energy performance and determine whether further engineering study and analysis are likely produce s ignificant energy savings. Monthly energy use and peak demands or, if available, interval billing data (such as 15-minute data), are reviewed to identify efficiency or behavior modification opportunities. As mentioned above, the PEA represents a valuable platform for the analyst that helps him to determine the building current energy consumption and the cost of this consumption and then comparing the consumption efficiencies with regard to similar buildings. This is normally done by calculating the energy use and cost per unit area per year, which can indicate the potential value of farther levels analysis. This preliminary analysis includes the following steps: 1. Determine the building s gross conditioned floor and record this on the basic building characteristic form. Classify the primary use of the building. Ensure that the standard definition of gross floor area is used, which is: The sum of the floor areas of all the spaces within the building with no deduction for the floor penetration other than atria. It is measured from the exterior faces of the exterior walls or from the centerline of the walls separating buildings, but it excludes covered walkways, open roofed-over areas, porches and similar spaces, pipe trenches, exterior terraces or steps, roof overhangs, all types of parking s, and similar features. 2. Assemble copies of utility bills and summarize them for at least one year period, and it is preferred for two or three years period. 3. Complete the energy performance summary to develop the EUI and the ECI for the building. 4. Compare the EUI and ECI with those of buildings having similar characteristics. Comparison should also be made with publicly available energy indices of similar buildings. In all cases, care should be taken to ensure that the comparison is made with current data, using consistent definitions of building usage and floor area. 5. Derive target energy, demand, and cost indices for a building with the same characteristics with the building being analyzed. A range of methods are available for this work, including: a. Choosing from any database of similar buildings those buildings with the lowest energy index. b. Choosing an index based on the knowledge of an energy analyst experienced with this type of buildings. 6. Compare the energy and cost of the savings to reach the targeted EUI. Using these values, determine whether further engineering analysis is recommended. 2.2 Walk-through analysis (Phase 1) First, the building s energy cost and efficiency are assessed by analyzing energy bills, complied in the PEA, and conducting a brief on site survey of the building. Phase 1 will consist of a survey identifying low-cost/no-cost measures improving energy efficiency and providing a listing of potential capital improvements that merit further considerations. Because calculations at this level are minimal, savings and costs are approximate. In addition to the information s collected in the PEA, the Walk-through phase will consist of the following: 1. Preform a brief walk-through survey of the facility to become fa miliar with its construction, equipment, operation, and maintenance. 2. Meet with owners/operator and occupants to learn of special problems or plane improvements of the facility and operation or maintenance issues. Determine whether any maintenance problems and/or practices affect efficiency. 3. Preform a space function analysis, that determine whether efficiency may be affected by function that differ from the original intent of the building. 4. Identify low-cost / no-cost changes to the facility or O&M procedures and estimate the approximate savings that will be results from these changes. 5. Identify the potential capital improvements for further study and provide an initial rough estimate of potential cost and savings. 2.3 Energy survey and analysis (Phase 2) In this phase an analytical procedure is guided by phase 1 analysis and includes the following additional steps: Volume 2 Issue 2 page 15

3 1. Review the mechanical and electrical design, installed condition, maintenance practices, and operating methods. 2. Describe and analyze the energy-using systems of the buildings, resulting from on-site observation, measurements, and engineering calculations. Phase 2 will consist of the following: Envelope Lighting: a) Lighting power density (w/m2) b) Lamp luminous efficacy (lm/w) c) Lamp control gear loss (w) Plug loads HVAC Laundry Water heaters Food preparation Refrigeration Conveying Pool/saunas/spas Process loads Others 3. Review existing O&M problems and logs. Review planned building changes or improvements and estimate their costs. 4. Measure key operation parameters and compare them to design levels, like operating schedules, heating/cooling water temperatures, the supply air temperature, the space temperature and humidity, ventilation quantities, and task lighting levels. Such measurements may be taken on sp ot basis or logged manually or electronically. 5. List all possible modifications to equipment and operations that will save energy. Select those that might be considered practical by the owner/operator and select those that will be analyzed further. Priorit ize the modifications in the anticipated ordered of implementation. 6. Estimate the implementation cost for each practical measure. 7. Estimate the impact of each practical measure on the building operation, maintenance cost, and nonenergy operation cost. 8. Prepare a financial evaluation to estimate the total potential investment using the owners/operators chosen technique and criteria. 2.4 detailed analysis (capital -intensive modifications) (Phase 3) Phase 3 analytical procedure is guided by phase 1 and phase 2 analysis and owners/operator s selection of measures of greater definition. It follows phase 1 and phase 2 work and includes the following additional steps: 1. Expand the definitions of all modifications requiring further analysis. Consider system interaction s to create integrated packages of recommendations. 2. Review measurement methods and preform additional testing and monitoring as required to allow determination of feasibility. 3. Preform accurate modeling of proposed modifications. Ensure that modeling includ es system interactions. 4. Prepare a schematic layout of each of the modifications. 5. Estimate the cost and savings of each modifications and each integrated bundle of modifications. Preform a LCCA to inform decision making. 6. Meet with the owner/operator to discuss/develop recommendations. Volume 2 Issue 2 page 16

4 Figure 1 will show the all phases of the EA: Preliminary Energy-Use Analysis (PEA) -Calculate Parameters -Compare to similar Phase 1: Walk-through -Rough cost and savings for EEMs -Identify capital projects Phase 2: Energy Survey & Analysis -End-use breakdown -Detailed Analysis -Cost & Saving for EEMs -O&M changes Phase 3: Detailed Analysis -Refined Analysis -Hourly Simulation -Additional Analysis Figure 1. EA Phases ENERGY AUDIT PROCESS In this part of the report the actual EA process will be applied by conducting the practices that should be done to the Preliminary Energy-Use Analysis (PEA) and the Walk-through (phase 1) only. 3.1 Preliminary Energy-Use Analysis (PEA) As mentioned above for the PEA stage, all affordable data with regard the building studied will be collected as in the following: Building General Information: The following are some general information s of the building: Project Name Industrial Training Institute-Shwiak (ITI) administration building Client Name The Public Authority of Applied Education and Training (PAAET) Volume 2 Issue 2 page 17

5 Site Address Shwiak technical compass Shwaik area Building Type and/or Functions Offices Lease Type Owned by PAAET The primary year of commissioning & Operation 2006 Floor # Space Function Type Gross Floor Weekly Operating Hours Weeks/ Year # Occupants # PCs Principal Lighting Type Principal HVAC Type G Office Down-light D. C %95 1 Office Down-light D. C %95 Total Peak Occupancy: % of Spaces Cooled Peak number of Full-time occupants 28 employees Description of activity level Light Disruption of clothing level Light - heavy Peak number of Temporary occupants Walk-through analysis (Phase 1) First, the building s energy cost and efficiency are assessed by analyzing energy bills, complied in the PEA, and conducting a brief on site survey of the building. Phase 1 will consist of a survey identifying low -cost/no-cost measures improving energy efficiency and providing a listing of potential capital improvements that merit further considerations. Because calculations at this level are minimal, savings and costs are approximate. In addition to the information s collected in the PEA, the Walk-through phase will consist of basic detailed information s about the building as in the following: brief walk-through survey Volume 2 Issue 2 page 18

6 Floor Energy Audits in Kuwait (case study of The Public Authority Applied for Education and Training... Total area Offices Hall Corridor Bathroom Kitchen stairs Others G st The targeted building visited many times to get familiar with its construction, equipment, operation, and maintenance. And many meetings were done with the building permanent/temp orary occupants (employees and visitors) and the following note was recorded: The building is cold (uncomfortable ambient indoor temperature) during the period between the end of summer and until the shut-off of the AC system at the beginning of winter that led them to open the windows and doors. The visitors Peak period stands for one month at the beginning of each semester (twice a year). Some fittings (down lights) have different color (color temperature) which led to uncomfortable light lighting Space Function Analysis In this section a preliminary area analysis is done for all floors of the building in a way to categorize each area and its use Building Lighting Analysis Several measurements were taken to the indoor lighting of the building using Lux meter and Thermal imager, and the results are as the following: Rooms illuminance The illuminance of some was measured using lux Figure 2: rooms (offices) of the building meter and the average was as in m Volume 2 Issue 2 page 19

7 Figure 2. Rooms actual illuminance Figure 3 shows the average illuminance for one room (office) of the building, and it is found that the room is over lightened knowing that the standards of electrical installation (British Standards BS R2) of Ministry of Electricity and Water (MEW) stands that the illuminance of the office should by 300 lx, which led that the office is over lightened with % Figure 3. Rooms average illuminance Rooms Light Fittings All the rooms equipped with 6 fluorescent 60x60 fittings Figure 4, each fitting include 4 lamps with 18w power each. The fittings also include choke coil with low power factor (PF=0.45 or %45) which leads that the fittings will consume more current to maintain the rated power, so a capacitor must be included to the fittings to correct the power factor (PF). Figure 4. Rooms 60x60 light fittings Room Light Power Density The room light power density (RLPD) is calculated by dividing the light fittings total power (in watt) of the room by its area (in ) as the following: Room Power (w) Room ( ) RLPD = = = 25 w/ Volume 2 Issue 2 page 20

8 Room Luminous Efficacy The room luminous efficacy (RLE) is calculated by dividing the total illuminance (in lumen (lm)) of the room by the light fittings total power (in watt) as the following: RLE = Room Power (w) Room illuminance (lm) = Fitting control gear losses = 21.6 lm/w The fitting control gear loses(fcgl) is the difference between the rated power of the fitting and the actual power measured for the fittings, and it found to be as follows: FCGL = Actual Power Rated Power = = 22 w Fittings Radiated heat The radiated heat from the fitting (for rooms and corridors) was measured using FLUKE thermal imager. Figure 5 shows thermal analysis for the Fluorescent 60x60 and compact fluorescent down light fittings: Figure 5. Fitting radiated heat From Figure 5 shows that the 60x60 fitting radiated heat is from 35 to 44 C, and the maximum heat (44 C) radiated from the lamps metal holders. Knowing that the AC temperature of rooms is C which lead that the fittings acts as air heaters that needs more power for the AC systems to compensate the radiated heat and this additional power is waste power that can be eliminated or reduced by applying some modifications Fittings Total Power The total power consumed by light fitting (P t ) equals the total rated power of the lamps (P r ) plus the power consumed by the control gear for the fitting (P c ), i.e. the power consumed by choke coil, starter The fitting total power is calculated as in the following: P t = P r + P c = (lamp rated power x 4) + P c = (18x4) + 22 = 94 w Lighting Power of the Building Knowing that the building is air-conditioned from discrete cooling substation, then the main load of the building is for lighting. The power consumed by the light fittings of the building is shown in the following tables: Ground Floor Lighting Power Volume 2 Issue 2 page 21

9 60 x 60 Down Light CFL (2x23w) Office Corridors & Entrance Bathroom & Kitchen Stair Hall Number of Fittings Rated Load (k w) Actual Load (k w) % From Total Actual Load Total Rated (k w) Actual (k w) Halogen (1x50w) 69.4% 20.9% 4.2% 1.6% 3.9% First Floor Lighting Power 60 x 60 Down Light CFL (2x23w) Office Corridors & Entrance Bathroom & Kitchen Stair Hall Number of Fittings Rated Load (k w) Actual Load (k w) % From Total Actual Load Total Rated (k w) Actual (k w) Halogen (1x50w) 80.2% 9.7% 4.5% 1.4% 4.2% Total Lighting Power of the building 60 x 60 Down Light CFL (2x23w) Office corridors & Entrance bathroom & Kitchen Stair Hall No R. Load(k w) Actual Load(k w) % from total Actual load Halogen (1x50w) 76.1% 15.9% 4.4% 1.5% 2.1% Volume 2 Issue 2 page 22

10 Total Rated (k w) Actual (k w) Simulink Output of a Designed Grid-connected PV Panel CONCLUSION This From the above analysis, it was concluded that: The building is over lightened. The overall lighting system have low Power Factor (PF) (0.54 to 0.72). The main fittings used are 60x60 Tube Fluorescent light fittings with 76.1%. The Compact Fluorescent Lamp fittings is 21.8% of the lighting system. Switches is the main control system used. The average energy consumed is calculated as follows: Energy consumed/year = hours/day/year X Power in kw = 8 h x 170 day x = 39,440 kwh The energy cost and bill are showed in the following table: Building Lighting Cost Fitting type 60x60 2x23w CFL 1x50 Halogen Consumption time Hour Day Year Hour Day Year Hour Day Year Power (kw) Old Bill in KD (0.002 kd/kw) New Bill in KD(0.025 kd/kw) Gov. cost KD (0.036 kd/kw) Total Bill in KD (0.002 kd/kw) 79.3 Total Bill in KD (0.025 kd/kw) Total cost in KD (0.036 kd/kw) The above table was calculated depending on the following: The operating hour are 8 hours per day. 5 days a week. 170 days a year. The initial cost of the fittings (fittings cost) was not included. The maintenance and spare parts cost (lamps, choke coil, starters ) were not included. RECOMMENDATIONS Regarding the analysis and results reached from the last section, the building needs urgent improvements to increase the efficiency and reduce the operating and maintenance cost for the lighting system. In the following some recommendations: 4.1 Replacing the lamps with LED s Volume 2 Issue 2 page 23

11 By replacing the existing lamps with LED s, large savings will be reached as in the following table: Ground Floor 60 x 60 Down Light CFL (2x23w) Office corridors & Entrance bathroom & Kitchen Stair Hall No Halogen (1x50w) R. Load(kw) Actual Load(kw) % from total Actual load 66.0% 24.8% 5.0% 1.9% 2.3% Total Rated (kw) 6.07 Actual (kw) 6.22 First Floor 60 x 60 Down Light CFL (2x23w) Office corridors & Entrance bathroom & Kitchen Stair Hall No R. Load(kw) Actual Load(kw) % from total Actual load 80.4% 12.2% 5.7% 1.7% 0.0% Total Rated (kw) 5.38 Actual (kw) 5.46 Halogen (1x50w) Total Lighting of the building 60 x 60 Down Light CFL (2x23w) Office corridors & Entrance bathroom & Kitchen Stair Hall No Halogen (1x50w) R. Load(kw) Actual Load(kw) % from total Actual load 72.7% 18.9% 5.3% 1.8% 1.2% Total Rated (kw) Volume 2 Issue 2 page 24

12 Actual (kw) Building Lighting Cost Fitting type 60x60 2x23w CFL 1x50 Halogen Consumption time Hour Day Year Hour Day Year Hour Day Year Power (kw) Old Bill in KD (0.002 kd/kw) New Bill in KD(0.025 kd/kw) Gov. cost KD (0.036 kd/kw) Total Bill in KD (0.002 kd/kw) 31.8 Total Bill in KD (0.025 kd/kw) Total cost in KD (0.036 kd/kw) The following table represents executive comparison between the existing and the recommended light fittings: Existing LED Savings % Power (kw) % Old Bill in KD (0.002 kd/kw/year) % New Bill in KD (0.025 kd/kw/year) % Gov. cost KD (0.036 kd/kw/year) % From the above analysis, it was clear the replacing the existing fittings will result a 60% savings on the operational cost only, putting in mind that the LED fittings last for hours with much better illumination than the fluorescent (7000 hours) and CFL (12000 hours). Also, the LED have much better efficiency (PF=0.9) as well as less heat emitting from the fittings which will led to additional savings. I. Appendix: Definitions: EA Energy Audit PEA Preliminary Energy-use Analysis ECI Energy Cost Index EUI Energy Utilization Index kbtu kilo British Thermal Unit O&M Operation and Maintenance HVAC Heating Ventilation, and Air Conditioning LCCA Life Cycle Cost Analysis EEM Energy Efficiency Measures D.C. Discrete Cooling ITI Industrial Training Institute-Shuwiak PAAET The Public Authority of Applied Education and Training MEW Ministry of Electricity and Water RLPD Room Light Power Density Volume 2 Issue 2 page 25

13 RLE FCGL PF CFL Room Luminous Efficacy Fitting Control Gear Loses Power Factor Compact Fluorescent Lamp REFERENCES [1] Energy management handbook/by Wayne C. Turner.4th ed. p. cm. Includes bibliographical references and index. ISBN x [2] Power resources--handbooks, manuals, etc. 2. Energy conservation--handbooks, Manuals, etc. I. Title. TJ T dc [3] Procedures for Commercial Building Energy Auditing, Second Edition, ISBN , 2004, 2011 ASHRAE [4] Guidelines on Energy Audit, Electrical & Mechanical Services Department, The Government of the Hong Kong Special Administrative Region, 2007 [5] Solutions manual for Guide to Energy Management, Fourth Edition By Klaus-Dieter E. Pawlik, Published by The Fairmont Press, Inc. 700 Indian Trail, Lilburn, GA tel: ; fax: ISBN X (The Fairmont Press,), ISBN (Marcel Dekker, Inc.) Volume 2 Issue 2 page 26