Sustainable use of energy- A case study on Energy Audit for Centre for Environmental Studies, Anna University (V. Vandhana Devi*) Abstract Climate Change & Global warming, ever increasing energy prices, acute energy shortage, forever widening and supply gap, hence energy efficiency and conservation measures have gained importance in the recent years. This paper involved an energy auditing with a view to enhance the existing energy efficiency level in the Centre for Environmental Studies, Anna University. Energy auditing is a systematic study of existing energy consumption pattern.
During the energy audit, a complete survey of power consumption in the Centre was carried out. Audit was conducted for lighting, fans, computers, Air conditioners and the laboratory equipment and their power consumption pattern was determined. The present energy consumption pattern of CES was identified and suitable energy conservation measures were suggested for minimising the power consumption in the centre. By implementing all the measures suggested, it is possible to mitigate about 33, 573 kg of carbon di oxide emissions, annually in the region. Energy conserved is energy produced.
This audit not only conserves energy but also produces energy. *Assistant Professor (Sr. Gr), Department of Civil Engineering, B. S Abdur Rahman University, Chennai – 600048 Sustainable use of energy- A case study on Energy Audit for Centre for Environmental Studies, Anna University (V. Vandhana Devi, Assistant Professor, Dept. of Civil Engg. B. S. Abdur Rahman University) 1. Introduction Energy is defined as the capacity to do work, motion, force, change in shape or form, to transfer heat. Energy audit is a technical analysis for identifying and quantifying energy utilization patterns. 2. Need for the present study
A survey of literature indicated that energy audit has been conducted for a variety of industries such as sugar, cement, leather, textile, iron and steel and refineries, etc. It has also been conducted for commercial establishments, hotels and software companies. However no attempt has been made to conduct energy audit for educational institutions. 3. Objectives of the study 4. Develop a suitable tool for energy audit for Centre for Environmental Studies 5. Review of energy related activities at CES 6. Measurement & Quantification of energy consumption by all utilities at CES 7.
Identify areas of energy wastage at CES 8. Development of energy management proposals 9. Preparation of Standard operating practices for efficient use of energy at CES 10. Create energy conservation measures 11. Methodology 12. Data Collection The number of lights, fans, computers and air conditioners, their type and their hours of usage were noted down. Using energy meter, the power consumed by the equipment such as Shaker, Muffle furnace, oven, BOD Aerator, refrigerator, incubator, COD Digester was determined for an hour. 13. Analysis of Data
The data collected were analysed to identify major energy consumers in CES. The energy consumption by all utilities at CES was measured and quantified. From the data, the monthly power consumption by CES was determined. 14. Energy Saving Calculation The present status of the energy consumption and the ststus after the implementation of the proposal were compared to determine the energy savings. Their difference gives energy savings in kWh. For one kWh of energy saved, it is possible to reduce 1. 04kg of carbon di-oxide emissions (Sethumadhavan, 2002). 15. Pay Back Period Calculation
Pay back period is defined as the length of time it will take an investment to return what put in. It is the period to recover the original or initial cost of the capital project out of the cash inflow generated from the capital project. It is also the pay-off or cash recovery. It is the ratio of the investment required and the savings achieved. Pay back period ( in years) = Investment (Rs. ) Savings ( Rs. ) 16. Energy Conservation Awareness Poster and handouts detailing the various aspects that promote energy conservation were prepared for the use of students and staff of CES. 17. Energy Audit Questionaire
A survey was conducted at CES using a structured questionnaire to collect primary data such as the energy sources for CES and the energy consumption per year etc. , which are used to prepare the energy profile. The questionnaire is shown below. Energy Audit Questionaire 18. Do you switch off the lights and the fans when you leave the room/ when they are not in use? Yes / No 19. What are the souces of energy for the electric utility serving CES? 20. How much total energy did CES consume in the last academic year? 21. What was the total cost of energy expenditures for the last year? 22. What is the electricity rate ( Rs. kWh)? 23. Do you have a stand by Diesel generator set at CES? Yes/ No 24. Do you face frequent power cuts ? If Yes, how many hours per week? 25. When do you use the Generator? Whenever power cuts/ only during emergencies. 26. How much is consumed by the Generator ( litres/ year)? 27. How many days in a month the Muthian Auditorium is used? 28. Results & Discussion Energy Profile of Centre for Environmental Studies Electrical energy consumption/ month-8,971 kWh Electrical energy consumption/ year-1,07,652 kWh Electricity charges paid per year-Rs. 4,75,396 Average cost of electricity / kWh-Rs. 4. 30 Power Factor-0. 5 ENERGY CONSERVATION MEASURES SUGGESTED FOR CES ECM No. 1- Replacement of the existing 40W Fluorescent Tube lights with Energy efficient 36W Fluorescent Tube lights. POSSIBLE LOCATIONS FOR REPLACEMENT OF THE 40W FTL BY 36W FTL AT CES |S. No |Location |No. of 40W |No. of 36W |Operating hours/day |Anticipated energy | | | |FTL proposed |FTL proposed | |savings/year (kWh) | |1 |Staff rooms |22 |20 |2100 |336. | |2 |Library |10 |5 |2100 |462. 0 | |3 |Lecture halls |15 |15 |1200 |72. 0 | |4 |Office |12 |6 |2400 |633. 6 | |5 |Wet Chemistry Laboratory |10 |5 |2100 |462. | |6 |Research Laboratory |8 |4 |2100 |369. 9 | |7 |Environmental Microbiology |10 |5 |2100 |462. 0 | | |Laboratory | | | | | |8 |GTZ Office |4 |4 |2400 |38. | |9 |Central Computer Lab |2 |2 |2400 |19. 2 | | |Total |93 |66 |21300 |2854. 2 | Replacement of 40W FTL with 36W FTL would help overcome the major disadvantages occurring in the halophospher conventional lights which include : eye fatigue, blackening of walls, poor output efficiency, low power factor, high power consumption. Economics No . 40W FTLs to be replaced = 93 No. of 36W FTLs to be proposed= 66
Possible Energy savings = 4W/ lamp Model calculation for the anticipated energy savings at Staff rooms Energy savings per year = (22 nos x 40 W x 2100 h/y) – (20 nos x 36W x 2100 h/y) = 336 kWh Possible total energy savings = 2854. 20 kWh Possible cost savings per year = 2854. 20 kWh/y x Rs. 4. 30 / kWh = Rs. 12,273. 06 Investment = nil The implementation of this proposal does not require any investment and the saving would be about Rs. 12,273 per year. by implementing these proposal, it is possible to mitigate about 350 kg carbon di-oxide emissions, annually in the region. ECM No. – Installation of an Energy saver for window air conditioners. The implementation of this proposal requires a one-time investment of about Rs. 29400 that would result in a savings of about Rs. 19504 per year with a pay back period of eighteen months. By implementing the proposal, it would be possible to mitigate about 4,717 kg of carbon dioxide emissions annually. ECM No. 3 – Installation of Variable Frequency Drives ( VFD) in Air conditioners. The implementation of this proposal requires a one time investment of about Rs. 60,000 that would result in a savings of about Rs. 59,598 per year with a pay back period of one year.
By implementing the proposal, it would be possible to mitigate about 14. 4 tons of carbon dioxide emissions annually. ECM No. 4 – Installation of high frequency Electronic Ballasts in place of Conventional Copper Chokes. The implementation of this proposal requires a one time investment of about Rs. 29,400 that would result in a savings of about Rs. 11,079 per year with a pay back period of31 months. By implementing the proposal, it would be possible to mitigate about 2680 kg of carbon dioxide emissions annually.
ECM No. – 5 Replace Group Switches by individual Pull Chord Switch The implementation of this proposal requires a one time investment of about Rs 9800 that would result in a savings of about Rs. 29349 per year with a pay back period of4 months. By implementing the proposal, it would be possible to mitigate about 7100 kg of carbon dioxide emissions annually. ECM No. 6 – Use of fans in air conditioned rooms The implementation of this proposal does not require any investment and the savings would be about Rs. 1032 per year. By implementing these proposals, it is possible to mitigate about 0. kg of carbon dioxide emissions annually. ECM NO . 7 – Switching off the computers during idle usage The implementation of this proposal does not require any investment and the savings would be about Rs. 13,545 per year. By implementing these proposals, it is possible to mitigate about 3276 kg of carbon dioxide emissions annually. ECM No. 8 – Installation of electronic regulator for ceiling fans The implementation of this proposal does not require any investment and the savings would be about Rs. 2064 per year. By implementing these proposals, it is possible to mitigate about 500 kg of carbon dioxide emissions annually.
ECM No. 9 – Installation of Automatic “ Occupancy Sensors” for lighting in selected locations The implementation of this proposal require an investment of Rs. 12,000 and the savings would be of about Rs. 2270 per year. By implementing these proposals, it is possible to mitigate about 550 kg of carbon dioxide emissions annually. Discussion Energy Conservation Measures (ECM) with investment and without investment have been suggested for possible energy savings. An energy saving potential of about Rs 1,50,716 per year can be achieved by implementing the proposals.
The implementation would require a one time investment of about Rs. 1,42,100 to reap the benefits. By implementing all the measures suggested, it is possible to mitigate about 33,573 kg of carbon dioxide emissions, annually in the region. The anticipated reduction in annual energy consumption at CES after implementing the Energy Conservation Measures is about 32, 292. 26 kWh per year. Present energy consumption at CES per year = 1,07, 651 kWh Anticipated energy consumption per year after implementing the proposals = 75, 358. 74 kWh SUMMARY AND CONCLUSION GENERAL
The energy conservation measures suggested fore Centre for Environmental Studies (CES) are implementable. Implementation of the measures suggested not only saves money and power but also help improve the quality of our environment. SUMMARY The energy audit for CES was conducted in two phases. The phase I, a survey of the literature was conducted. The scoping and the methodology for conducting the audit were finalized. Preliminary data for preparing the audit tool were also collected. Energy related activities at CES were reviewed and measurement and quantification of energy consumption by all utilities at CES were made.
The phase II, additional data were collected for appropriate applications. Based on the findings, energy conservation measures were identified and their economics calculated . Specific recommendations for energy saving at CES were made. The following table lists the energy conservation measures, the investment required, the savings and their pay back period. LIST OF ENERGY MEASURES SUGGESTED FOR CES |S. No |Energy conservation measures |Investment (Rs. ) |Annual Savings (Rs. )|Pay back period |Reduction in Co2 | | | | |(months) |emissions (kg) | |1 |Replacement of the existing 40W Fluorescent Tube |Nil |12,273. 06 |Nil |350 | | |lights with Energy efficient 36W Fluorescent Tube | | | | | | |lights | | | | | |2 |Installation of an Energy saver for window air |29,400 |19,504. 0 |18 |4,717 | | |conditioners | | | | | |3 |Installation of Variable Frequency Drives ( VFD) |60,000 |59,598 |12 |14,400 | | |in Air conditioners | | | | | |4 |Installation of high frequency Electronic Ballasts|29,400 |11,079. 8 |31 |2,680 | | |in place of | | | | | | |Conventional Copper Chokes | | | | | |5 |Replace Group Switches by individual Pull Chord |9,800 |29,349. 5 |4 |7,100 | | |Switch | | | | | |6 |Use of fans in air conditioned rooms |Nil |1,032 |Nil |0. | |7 |Switching off the computers during idle usage |Nil |13,542 |Nil |3,276 | |8 |Installation of electronic regulator for ceiling |1,500 |2,064 |9 |500 | | |fans | | | | | |9 |Installation of Automatic “ Occupancy Sensors” for|12,00 |2,270. 0 |63 |550 | | |lighting in selected locations | | | | | | |Total |1,42,100 |1,50,716. 29 | |33,573 | CONCLUSION Each energy conservation measures should be given a top priority to achieve energy savings and each proposal should be assigned to specific operating or maintenance personnel for implementing and monitoring.
All implemented proposals are to be monitored on a proposal by proposal basis for quantifying the actual achievement of savings obtained on a monthly basis. There exists wide scope to conserve energy and environment by conducting energy audit. By implementing the proposal suggested, the following economic and environment benefits could be achieved: 29. Reuction of power cost at Centre for Environment Studies 30. Prevention of atmosphere emissions of carbon dioxide to the tune of about 33,573 kg per year
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