OFF THE GRID
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Presentation Transcript
OFF THE GRID Property Irrigation System Alex Chepeska
Outline • Project Objective • Background • Design Decisions • Analysis and Testing • Results • Implications and Future Recommendations
Goals and Objectives • Design irrigation system for remote areas of property with sparse water • Automate system • Must run without access to conventional power • Modify existing design • Increase functionality • Manufacture using readily available materials • Low cost • “Do-it-yourself” kit
Previous System • Springs along stream served as water source • Pump at each spring • As output decreases more pumps added • 4 years of dry summers + 4 springs + 8 pumps =60 GPH
Current System • 4000 sq. ft. garden space • 6 foot well producing 120 GPH • 4 pumps deliver water up 12 feet to crops • Distributed via drip irrigation • Solar panels to charge 12v batteries • Requires 2491 gallons/week
Problems • Clogging pumps and tubing • When system is off water flows backward into well • Well produces 1/5 of the pumps capacity • Weather limits solar panel use • Pumps consume extra amps when batteries are full • Abundant water overflows stations
Design Concept 2: • Completely covered pumps, covered reservoir, tighter seals and screened irrigation output, backflow valves, full well operation, automatic shutdown, windmill/central control box, weatherproofed for winter, windmill charges extra batteries, 110v pump
Other Design Decisions FMEA Design for X analysis • Manufacture • Assembly • Maintenance • Recycling
Windmill • Type • Size • Blades • Permits
Windmill Base • 1/8” angle iron • 12’ in height • Triangular shape • Setup instructions • 20-6’ sections
Windmill Blades • PVC • Home made construction • Cut into quarters
Generator • Home Made • Alternator • Permanent magnet generator
Pump Selection • 110v Sump Pump • Inverted from 12v battery • $70-$80 • Replaces multiple 12v pumps
Reservoir • Sold at many stores • Easy to maintain • Under $50 • Screen or full cover
Automation Control • Backflow prevention valve • Auto shutoff • Rain sensor • Control box
Results GPM = (HP*2178) / Feet of head = (1/6*2178) / 12 = 30.25 GPM Pump ran for 30 minutes So ….→ 30.25 GPM * 30 minutes = 907.5 gallons pumped
Battery Usage • Plan for 12,000 sq. ft. * 1” per week= 1000 cubic feet 1000 * 7.48 gal./cubic foot = 7,480 gallons • 1 battery can pump 907.5 gallons 7,480 / 907.5 = 8.24 batteries per week
Windmill Charge Time • 6 foot diameter Blades • Ave wind speed = 10 mph
Windmill Charge Time • This gives approximately 51 Watts output 50 W/ 12v *24 Hrs= 100 amp-hrs of charge • Batteries require 75 amp-hours to fully charge • 50 W/ 12v * X hrs = 75 amp-hours X= 18 hours to charge 1 battery
Implications • Find way to charge/discharge all batteries in succession • Lead-Acid batteries maintain voltage when dead • Parallel setup • One way diode
Conclusions • Input spreadsheet with recommended specifications • Can be applied to any size property/budget • Feasible, but needs more physical testing
Do-It-Yourself Kit • Spreadsheet • Windmill building instructions • Windmill blade creation instructions • Recommended products • Entire system assembly instructions
Future Recommendations • Generator construction • Different windmill designs • Fully constructed system and testing