Field Testing of A/C Technology Options: Lessons Learned in Samoa Dilip R. Limaye Regional Energy Efficiency Workshop Samoa, March 3-4. 2015
Importance of A/C in Samoa Air conditioning represents about 50% of the energy consumption in government buildings and contributes about 40% of peak load Most air conditioners in government buildings are standard split units that have rated EERs in the range of 2.3 to 2.9. For older units, the EER may be even lower. Improving the efficiency of air conditioners therefore is a high priority in Samoa. 2
Efficient A/C Technologies Existing A/Cs in government buildings: EER 2.3 to 2.9 Inverter A/Cs: EER 3.4-3.6 Solar Hybrid A/Cs: EER 3.4 to 3.8 Smart Controllers for Existing A/Cs: Improvement 10 to 30 % 3
Inverter Technology Traditional ACs regulate temperature by using a compressor that is either working at maximum capacity or switched off entirely. Inverter-ACs have a variable-frequency drive with an adjustable electrical inverter to control the motor speed and the compressor and cooling output. 4
Inverter A/Cs 5
Testing of Inverter A/Cs Testing of inverter A/Cs conducted by Australia Pacific Technical College (APTC) in two locations: National University of Samoa Ministry of Natural Resources & Environment - Weather Station 6
Testing at NUS NUS Mon pm NUS Tues PM 100.00% 100.00% Amps 50.00% 0.00% NUS Mon pm 50.00% 0.00% 13:01 13:51 14:41 15:31 16:21 17:11 18:01 18:51 19:41 20:31 21:21 22:11 23:01 23:51 13:01 13:56 14:51 15:46 16:41 17:36 18:31 19:26 20:21 21:16 22:11 23:06 Amps NUS Tues PM 7
Test Results - NUS NUS - Staff room Unit Running Amps Run time/24hrs Cost/day Cost/year Capital Cost Polar Air KF70GW/BC 7.0KW Panasonic CSS24MKH 6.5KW 10.8 15 38.88 9,720 2,399 8.2 15 29.52 7,380 5,900 Cost saving/year 2,340 Capital difference 3,501 Payback period 18 months 8
Testing at MNRE Weather Station 9
Test Results - MNRE Unit Polar Air KF66GW/BC 6.6KW Daikin FTKS60LVMA 7.1KW Running Amps Run time/24hrs MNRE Cost/day Cost/year Capital costs 11.5 19.6 54.75 19,983 2,399 9.4 19.6 46.42 16,946 5,900 Cost saving/year 3,037 Capital difference 3,501 Payback period 14 months 10
Solar Hybrid A/C A solar hybrid air conditioner uses solar energy as a supplement to electric power to increase the efficiency of air conditioning. Solar hybrid A/C units manufactured in China are available in the PDMCs and have been installed in a hotel in Vanuatu The PEEP2 project has assessed the current status and prepared a report on technology assessment of energy efficient technologies for the Pacific Island nations. Results indicated that solar hybrid air conditioners may be 25 to 35% more efficient. Limited data available on performance in the Pacific Islands 11
Solar Hybrid A/C 12
Solar Hybrid A/C 13
Testing of Solar Hybrid A/C Test unit installed at Mapuifagalele Little Sisters of the Poor old age home Measurements conducted using data logger for one month Energy savings of 34% recorded 14
Smart Controller Decreases the A/C energy consumption by reducing the run times on the A/C compressor. It has embedded in it smart technology to analyze the temperature of the unit and control its operation to prevent overcooling. The smart controller contains software that can be continually and dynamically applied to any cooling unit during its operation. 15
Testing of Smart Controllers Smart Controllers (3) obtained from a supplier Installed at 3 locations Measurements with data logger over 2 weeks Varying levels of savings recorded from 3% to 34% Low savings for undersized A/Cs that run 100% of the time; high savings for variable loads and oversized A/Cs Low cost of equipment provides attractive paybacks (<2.5 years) even with 5% savings 16
Design of Demonstration Project Grant from ADB/GEF for equipment : Government buildings 100% Private Sector (Hotels) 50% Installation costs paid by recipient Disposal of replaced A/Cs with recovery of refrigerant (by MNRE) Measurement and Verification by PEEP2 team 17
Inverter A/Cs Government Buildings Agency Number of Units by Capacity 2.6 kw 3.5 kw 5.3 kw 7.0 kw Total Little Sisters Of The Poor 6 1 1 0 8 National Health Service 1 0 9 1 11 National University of Samoa 0 0 5 7 12 SNPF Builidng 7 7 1 0 15 Total 14 8 16 8 46 18
Projected Energy Savings Government Agency Number of Existing A/Cs Existing EER Baseline Energy (kwh) Inverter EER Inverter Energy (kwh) Savings (kwh) % Savinga Mapufagalale - Little Sisters of the Poor National Health Service National University of Samoa Samoa National Provident Fund 8 2.4-2.8 62,091 3.6 43,411 18,680 30.1% 11 2.6-2.7 59,777 3.6 44,002 15,775 26.4% 12 2.6-2.7 38,006 3.6 27,981 10,025 26.4% 15 2.5-3.0 27,656 3.6 21,382 6,274 22.7% Total 46-187,529 136,776 50,753 27.1% 19
Inverter A/Cs - Hotels Hotel Number of Units by Capacity 2.6 kw 3.5 kw 5.3 kw 7.0 kw Total Pacific Pearl 4 4 2 7 17 Vaisala 4 0 3 0 7 Total 8 4 5 7 24 Hotel Number of Existing A/Cs Baseline Energy (kwh) Inverter Energy (kwh) Savings (kwh) % Savinga Pacific Pearl 17 44,498 33,432 11,066 24.9% Vaisala 11 16,546 11,396 5,150 31.1% Total 28 61,043 44,828 16,215 26.6% 20
Solar Hybrid A/Cs Agency Ministry of Natural Resources and Environment (MNRE) Scientific Research Organization of Samoa (SROS) Number of Units by Capacity 2.6 kw 3.5 kw 5.3 kw 7.0 kw Total 3 1 0 3 7 0 0 1 3 4 Total 3 1 1 6 11 21
Projected Energy Savings Government Agency Number of Existing A/Cs Existing EER Baseline Energy (kwh) Solar Hybrid EER Solar Hybrid Energy (kwh) Savings (kwh) % Savinga Ministry of Natural Resources and Environment (MNRE) Scientific Research Organization of Samoa (SROS) 7 2.1-2.9 20,286 3.6 12,651 7,635 37.6% 4 1.9-2.5 58,380 3.6 42,443 15,937 27.3% Total 11-78,666 55,094 23,572 30.0% 22
Smart Controllers 20 smart controllers procured Installations in 2 government agencies National University of Samoa (NUS) Samoa National Provident Fund (SNPF) Building To maximize savings, controllers were installed where the A/C was oversized or when there was a considerable change in the cooling load during the day or season 23
Project Cost A/C in Government Buildings Supply and delivery of: 46 Inverter A/C units... $57,040 11 Solar Hybrid Units...,.. $21,107 20 Smart Controllers... $ 5,000 30 Energy Meters... $ 1,500 The requested total ADB contribution... $ 84,647 Costs of installation and disposal to scrappage facility; and removal of refrigerant... $15,320 Total Cost $99,967 24
Impacts and Benefits Impacts Total electricity savings (end-use level): 79,526 kwh/year EPC generation savings: 96,629 kwh/year EPC diesel savings: 25,563 litres/year GHG emission reduction (CO2e/year): 77.3 tons Total Cost. $99,967 Expected Savings. $35,787 Simple Payback. 2.8 years 25
Summary of Hotels Project Overall project cost: US$37,820 Total electricity savings/year (end-use): US$ 7,297 EPC generation savings (kwh/year): 96,629 EPC diesel savings (Litres/year): 25,563 GHG emission reduction (CO2e/year ): 77.3 tons Simple Payback Period (years): 5.2 years Payback based on ADB Costs: 2.6 years Payback to Pacific Pearl Hotel: 2.9 years Payback to Vaisala Hotel : 2.1 years 26
Concluding Remarks Efficient air conditioning technologies are available and cost effective Testing of all 3 technologies provided positive results Substantial energy and economic benefits can be achieved Preliminary M&V results: Inverter savings appear to be higher than estimates Solar A/c savings appear to be lower Smart controller measurements in progress Detailed M&V results will be available by April 2015 27
Thank You Dilip R. Limaye dlimaye@srcglobal.com