OFF THE GRID

1. OFF THE GRID Property Irrigation System Alex Chepeska

2. Outline • Project Objective • Background • Design Decisions • Analysis and Testing • Results • Implications and Future Recommendations

3. 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

4. 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

5. 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

6. 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

7. Possible Concepts

8. 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

9. Other Design Decisions FMEA Design for X analysis • Manufacture • Assembly • Maintenance • Recycling

10. Windmill • Type • Size • Blades • Permits

11. Windmill Base • 1/8” angle iron • 12’ in height • Triangular shape • Setup instructions • 20-6’ sections

12. Windmill Blades • PVC • Home made construction • Cut into quarters

13. Generator • Home Made • Alternator • Permanent magnet generator

14. Pump Selection • 110v Sump Pump • Inverted from 12v battery • $70-$80 • Replaces multiple 12v pumps

15. Reservoir • Sold at many stores • Easy to maintain • Under $50 • Screen or full cover

16. Automation Control • Backflow prevention valve • Auto shutoff • Rain sensor • Control box

17. Material List

18. Testing

19. 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

20. 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

21. Average Wind power

22. Windmill Charge Time • 6 foot diameter Blades • Ave wind speed = 10 mph

23. 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

24. Implications • Find way to charge/discharge all batteries in succession • Lead-Acid batteries maintain voltage when dead • Parallel setup • One way diode

25. Conclusions • Input spreadsheet with recommended specifications • Can be applied to any size property/budget • Feasible, but needs more physical testing

26. Do-It-Yourself Kit • Spreadsheet • Windmill building instructions • Windmill blade creation instructions • Recommended products • Entire system assembly instructions

27. Future Recommendations • Generator construction • Different windmill designs • Fully constructed system and testing

28. Questions