Electrical Power Analysis of the Cal Poly Organic Farm for the Cal Poly SuPER Project Presentation For SARC March 21, 2008 Senior Project By Alex Liang
Agenda Terminology Introduction to SuPER and This Project Electrical Analysis of Organic Farm Power Measurement of Organic Farm AC Power Summary DC Power Analysis SuPER Field Testing Conclusion Future Studies Discussion
About Me Electrical Engineering Senior Emphasis in Power Systems Interned at SFPUC, NUMMI Will be working at PG&E Substation Design Engineer Originally from Fremont, CA
Terminology SuPER Sustainable Power for Electrical Resources Load any device that uses electricity
Terminology Watts measurement of power how much power it is using Light bulb = 50 watts, hairdryer = 1800 watts Watt-hours how much energy has been used (watts) x (time in hours) Light bulb on for 2 hours (50 watts) x (2 hours) = 100 watt-hours
Terminology AC alternating current 110V from wall outlets DC direct current 1.5V from an AA battery
Introduction to SuPER To develop a standalone, low cost, sustainable solar power system Aimed to bring power to the 2 billion people who currently do not have access to it Cost less than $500 Lifecycle of 20 years
Introduction to SuPER SuPER project 2 years running All work performed by students First prototype built Capable of at least 700 watt-hours per day Testing with small loads outside of laboratory
Introduction to Project Perform electrical analysis of Organic Farm Investigate all loads used at the farm Develop schematic of electrical system Perform power consumption measurements Converting farm to DC system How to utilize SuPER systems at the farm
How this project began Read about SuPER Project Met with Dr. Jim Harris SuPER Field Testing Organic Farm going solar Apply internship experience
Cal Poly Organic Farm
First Farm Visit Neal MacDougall Quick tour of farm and buildings Size the scope of project
Electrical Analysis Consulted Dennis Elliot Monthly utility meter data Monthly power usage in kilowatt-hours Monthly cost in dollars
Cal Poly Organic Farm Electricity Usage, July 2006 to June 2007 1400 $600.00 1200 1250 1180 1220 1350 $500.00 1000 $400.00 Power Used (kwh) 800 600 400 200 700 690 680 530 $136.78 $140.32 $123.48 $106.12 620 $96.75 560 $86.90 $181.17 720 $108.26 630 $95.56 $172.01 $260.35 $235.70 $300.00 $200.00 $100.00 Cost ($) kwh Used Cost 0 Jul Aug Sep Oct Nov Dec Jan Feb Mar Apr May Jun Month $0.00 Average monthly usage = 844 kwh,, Average monthly cost = $145.28 Average daily usage = 28.133 kwh
Electrical Analysis Loads at the farm Investigated the loads present Building by building Read electrical ratings to determine watts Measured watts using Kill-A-Watt meter Estimate of how much power each building uses
Electrical Analysis Packing Shed Loads # Load Name 1.1 Vegetable Spinner 1.2 Stereo 1.3 Toaster Oven 1.4 Microwave Oven 1.5 Digital Scales (2) 1.6 Water Heater 1.7 Mini Fridge 1.8 Outdoor Lamps (4) 1.9 Fluorescent lamps (15) Total Watts 100 W 5 W 1360 W 925 W 10 W total 2000 W 115 W 285 W total 330 W total 5,130 W
Electrical Analysis Straw Bale House & Storage Shed Loads # Load Name 2.1 Laser Printer 2.2 Computer 2.3 Monitor Total Watts 6W / 340 W 80 W 40 W 126 W / 460 W # Load Name 3.1 Fluorescent lamps (2) Total Watts 65 W 65 W
Electrical Analysis Greenhouse & Other Loads # Load Name 4.1 Blower fan 4.2 Exhaust fan (2) 4.3 Circulation fan 4.4 Motorized shutter 4.5 Vacuum Total Watts 67 W 1,480 W total 248 W 17 W 700 W 2,512 W # Load Name 5.1 Pond pump Total Watts 800 W 800 W
Electrical Analysis Instantaneous power use (watts) More useful is energy used in a day (watt-hours) Estimates from farm personnel Data from power measurement
Electrical Analysis Summary of Power Usage # Building / Area Total Power Per Day 1 Packing Shed 4,712.4 Wh 2 Straw Bale House 806.4 Wh 3 Storage Shed 13.33 Wh 4 Greenhouse 13,837 Wh 5 Pond Pump 480 Wh Total 19,848.73 Wh
Electrical Analysis Packing Shed Load Schedule # Load Name 1.1 Vegetable Spinner 1.2 Stereo 1.3 Toaster Oven 1.4 Microwave Oven 1.5 Digital Scales (2) 1.6 Water Heater 1.7 Mini Fridge 1.8 Outdoor Lamps (4) 1.9 Fluorescent Lamps (15) Watts 100 W 5 W 1360 W 925 W 10 W total 2000 W 115 W 285 W total 330 W total Hours Per Week Avg. Power Per Day 1 14.3 Wh 16 0.5 0.5 10 6 28 30 30 Total 11.4 Wh 97.1 Wh 66 Wh 14.3 Wh 1714 Wh 160 Wh 1221 Wh 1414.3 Wh 4,712.4 Wh
Electrical Analysis Straw Bale House & Storage Shed Load Schedules # Load Name 2.1 Laser Printer 2.2 Computer 2.3 Monitor Watts 6W / 340 W 80 W 40 W Hours Per Day Avg. Power Per Day 0.5 / 0.01 3 / 3.4 Wh 9 2 Total 720 Wh 80 Wh 806.4 Wh # Load Name 3.1 Fluorescent Lamps Watts 80 W Hours Per Day Avg. Power Per Day 0.167 13.33 Total 13.33 Wh
Electrical Analysis Greenhouse & Other Load Schedules # Load Name 4.1 Blower fan 4.2 Exhaust fan (2) 4.3 Circulation fan 4.4 Motorized shutter 4.5 Vacuum Watts 67 W 1480 W total 248 W Hours Per Day 17 W (seconds) Avg. Power Per Day 24 1608 Wh 5 19 7400 Wh 4712 Wh negligible 700 W 0.167 116.9 Total 13,837 Wh # Load Name 5.1 Pond Pump Watts 800 W Hours Per Day Avg. Power Per Day 0.6 480 Total 480 Wh
Electrical Analysis Electrical schematic Shows each circuit Single Line Diagram One circuit = one circuit breaker, wire, loads
Power Measurement Individual loads: Kill-A-Watt Meter Only for plug-in loads
Power Measurement Measured farm s s total power consumption PowerSight meter installed at circuit breaker panel Gathered data for a week Provided power used by greenhouse fans, lighting; time on Provided peak power (highest watts seen)
4000 3500 3000 2500 2000 1500 1000 500 0 Organic Farm Power Consumption Thursday 02/28/08 11:00:00 11:30:00 12:00:00 12:30:00 13:00:00 13:30:00 14:00:00 14:30:00 15:00:00 15:30:00 16:00:00 16:30:00 17:00:00 17:30:00 18:00:00 18:30:00 19:00:00 19:30:00 20:00:00 20:30:00 21:00:00 21:30:00 22:00:00 22:30:00 23:00:00 23:30:00 0:00:00 Time 80 70 60 50 40 30 20 10 0 Power (Watts) Temperature (ºF) Power Temperature @ 12:30PM: Exhaust fans, blower fan, pond pump, stereo on
4000 3500 3000 2500 2000 1500 1000 500 0 Organic Farm Power Consumption Friday 02/29/08 0:00:00 1:00:00 2:00:00 3:00:00 4:00:00 5:00:00 6:00:00 7:00:00 8:00:00 9:00:00 10:00:00 11:00:00 12:00:00 13:00:00 14:00:00 15:00:00 16:00:00 17:00:00 18:00:00 19:00:00 20:00:00 21:00:00 22:00:00 23:00:00 0:00:00 Time 80 70 60 50 40 30 20 10 0 Power (Watts) Temperature (ºF) Power Temperature Power was unplugged or unit's memory prematurely filled up. @ 3:30PM: Circulation fan, blower fan, computer + monitor on
4000 3500 3000 2500 2000 1500 1000 500 0 Organic Farm Power Consumption Saturday 03/01/08 0:00:00 1:00:00 2:00:00 3:00:00 4:00:00 5:00:00 6:00:00 7:00:00 8:00:00 9:00:00 10:00:00 11:00:00 12:00:00 13:00:00 14:00:00 15:00:00 16:00:00 17:00:00 18:00:00 19:00:00 20:00:00 21:00:00 22:00:00 23:00:00 0:00:00 Time 80 70 60 50 40 30 20 10 0 Power (Watts) Temperature (ºF) Power Temperature @ 6:30PM: Circulation fan, blower fan, computer + monitor on
4000 3500 3000 2500 2000 1500 1000 500 0 Organic Farm Power Consumption Sunday 03/02/08 0:00:00 1:00:00 2:00:00 3:00:00 4:00:00 5:00:00 6:00:00 7:00:00 8:00:00 9:00:00 10:00:00 11:00:00 12:00:00 13:00:00 14:00:00 15:00:00 16:00:00 17:00:00 18:00:00 19:00:00 20:00:00 21:00:00 22:00:00 23:00:00 0:00:00 Time 80 70 60 50 40 30 20 10 0 Power (Watts) Temperature (ºF) Power Temperature @ 4:00PM: Exhaust fans, blower fan, computer + monitor on
4000 Organic Farm Power Consumption Monday 03/03/08 80 Power Temperature 3500 70 3000 60 2500 2000 1500 50 40 30 1000 20 500 10 0 0 0:00:00 1:00:00 2:00:00 3:00:00 4:00:00 5:00:00 6:00:00 7:00:00 8:00:00 9:00:00 10:00:00 11:00:00 12:00:00 13:00:00 14:00:00 15:00:00 16:00:00 17:00:00 18:00:00 19:00:00 20:00:00 21:00:00 22:00:00 23:00:00 0:00:00 Time Power (Watts) Temperature (ºF) Power was unplugged or unit's memory prematurely filled up. @ 6:15PM: Circulation fan, blower fan, computer + monitor, Packing Shed lights on
4000 Organic Farm Power Consumption Tuesday 03/04/08 80 Power Temperature 3500 70 3000 60 2500 50 2000 40 1500 30 1000 20 500 10 0 0 0:00:00 1:00:00 2:00:00 3:00:00 4:00:00 5:00:00 6:00:00 7:00:00 8:00:00 9:00:00 10:00:00 11:00:00 12:00:00 13:00:00 14:00:00 15:00:00 16:00:00 17:00:00 18:00:00 19:00:00 20:00:00 21:00:00 22:00:00 23:00:00 0:00:00 Temperature (ºF) Time @ 6:20PM: Circulation fan, blower fan, air pump, pond pump, computer + monitor on Power (Watts)
4000 Organic Farm Power Consumption Wednesday 03/05/08 80 Power Temperature 3500 70 3000 60 2500 50 2000 40 1500 30 1000 20 500 10 0 0 0:00:00 1:00:00 2:00:00 3:00:00 4:00:00 5:00:00 6:00:00 7:00:00 8:00:00 9:00:00 10:00:00 11:00:00 12:00:00 13:00:00 14:00:00 15:00:00 16:00:00 17:00:00 18:00:00 19:00:00 20:00:00 21:00:00 22:00:00 23:00:00 0:00:00 Temperature (ºF) Time @ 6:05PM: Circulation fan, blower fan, air pump, pond pump, computer + monitor on Power (Watts)
4000 Organic Farm Power Consumption Thursday 03/06/08 3500 3000 2500 2000 1500 1000 500 0 0:00:00 1:00:00 2:00:00 3:00:00 4:00:00 5:00:00 6:00:00 7:00:00 8:00:00 9:00:00 10:00:00 11:00:00 12:00:00 13:00:00 14:00:00 15:00:00 16:00:00 17:00:00 18:00:00 19:00:00 20:00:00 21:00:00 22:00:00 23:00:00 0:00:00 Time @ 4:45PM: Circulation fan, blower fan, air pump, pond pump, computer + monitor, Packing Shed lights, stereo on 80 70 60 50 40 30 20 10 0 Power (Watts) Temperature (ºF) Power Temperature
4000 Organic Farm Power Consumption Friday 03/07/08 80 70 3500 60 3000 50 40 30 2500 2000 1500 1000 500 Power Temperature 0 0:00:00 0:30:00 1:00:00 1:30:00 2:00:00 2:30:00 3:00:00 3:30:00 4:00:00 4:30:00 5:00:00 5:30:00 6:00:00 6:30:00 7:00:00 7:30:00 8:00:00 8:30:00 9:00:00 9:30:00 10:00:00 10:30:00 11:00:00 11:30:00 12:00:00 12:30:00 13:00:00 13:30:00 14:00:00 14:30:00 15:00:00 Temperature (ºF) Time @ 3:18PM: Exhaust fans, blower fan, air pump, pond pump, computer r + monitor on Power (Watts) 20 10 0
Keeping the Farm AC with Solar Power Pros Keep existing loads and electrical system intact Easy to install Easy to switch back to grid power Cons Solar inherently DC Require DC AC inverters If using SuPER, require 65 units $500 each $32,500 total Not feasible
Keeping the Farm AC with Solar Power Hire contractor to perform install Grid supplement VS standalone system Highest energy used last year June 07: 1350 kwh; 45 kwh per day Total energy used last year 8,900 kwh; $1743.40
Keeping the Farm AC with Solar Power Percentage of Power Supplied By Solar Power Estimated Cost Greenhouse Gases Saved Over 25 Years 25% $15,000 46.0 Tons 50% $27,000 91.0 Tons 75% $40,500 137.0 Tons 100% $54,000 182.0 Tons Source: www.findsolar.com
Walker Creek Ranch Solar Installation
Keeping the Farm AC with Solar Power Reducing energy consumption Water heater & mini fridge Computer & monitor Packing Shed lighting on harvest days timer Pond pump timer
Converting the Farm to DC Why DC? with Solar Power Solar panels output DC No need for DC AC inverter Many electronic devices are DC Computers, battery charger, AC adapter
Converting the Farm to DC Efficient LED lighting 2ft LED tube = 3 W with Solar Power 4ft Fluorescent tube = 40 W Getting brighter and better with increasing technology
Converting the Farm to DC with Solar Power Replace loads with their DC equivalents RV market many 12V / 24V DC appliances For existing DC loads (stereo, digital scales) use DC-DC converter Circuit that changes the DC voltage 12V car charger for cell phones For loads without DC equivalents, use DC AC inverter (veg( veg.. spinner)
Converting the Farm to DC with Solar Power Replace all lighting with LED lighting Solar water heater Replace computer + monitor with laptop Combined 120 W vs 60 W laptop Replace laser printer with inkjet Printing: 340 W vs 25 W Replace Greenhouse fans motors with DC motors of same size
Converting the Farm to DC with Solar Power Pros Reduce power consumption No need for inverters to be running continuously # of SuPER units needed drops to 15 $7,500 Cons Requires modification to electrical system Estimated parts cost $4,258 Requires inverters to use AC loads Require AC DC rectifiers to use grid power (backup)
Converting the Farm to DC with Solar Power May or may not be feasible for this farm Good idea for a farm currently without any electricity Rural areas No local utility
SuPER Field Testing 15 SuPER units still a large number, especially for field testing Greenhouse needs 13 of them Focus on powering all but the Greenhouse Only requires 2 units Feasible number of units to build These buildings loads provide good simulation of household loads
SuPER Field Testing Convert these buildings to DC $2,955.33 in replacement parts Install AC DC rectifiers for backup (~$350) Leave Greenhouse AC Still have AC power available at the farm
SuPER Field Testing Packing Shed w/ DC loads Estimated 633.5 watt-hours per day Can use one SuPER unit Install behind building or on roof
SuPER Field Testing Packing Shed SuPER Location
SuPER Field Testing Straw Bale House & Storage Shed w/ DC loads Estimated 318.8 watt-hours per day Can use one SuPER unit Trees around building Install away from trees
SuPER Field Testing Straw Bale House SuPER Locations
Conclusion # Building / Area Total Power Per Day (AC) Total Power Per Day (DC) 1 Packing Shed 4,712.4 Wh 633.5 Wh 2 Straw Bale House 806.4 Wh 3 Storage Shed 13.33 Wh 4 Greenhouse 13,837 Wh Total 19,369.13 Wh 317.8 Wh 0.96 Wh 12,200 Wh 13,152.26 Wh
Future Studies Electronics Related Projects DC-DC converters, DC-AC inverters, AC-DC rectifiers LED lighting system
Solar water heater Future Studies Other Projects More efficient methods of heating/cooling foods Wind power
Review literature Future Studies Greenhouse Thorough analysis of energy requirements Optimize performance (energy)
Discussion Questions? Comments?