This project is to design and build a cheap solar water pump for agricultural use. A farming friend bought a pump for $1000, and having repaired it, I thought I could produce something similar for a fraction of the price.
The client suggested a head of 2 m with a pumping rate of around 2000 L/day would be a good target. Given that there are roughtly 7 hours of insolation per day, this corresponds to around 300 L/hour. On eBay, I managed to find 12 V and 24 V versions of a 5 m, 800 L/hour pump. Since 5 m is probably the max head, I might expect a flow rate of approximately 0 L/hour for 5 m, and therefore around 500 L/hour for 2 m of head. This meets the requirement. The pump is centrifugal, but submersible, so it won't need to be self priming. It draws a maximum of around 1 A for the 24 V version, so a 40 W panel would be overkill, but cost effective in terms of $/W.
| Item | Price ($ AUD) |
|---|---|
| 40 W solar panel | 47 |
| 24 V pump | 14 |
| Wiring | ~20 |
| Diode | ~0 |
Next actions:
I properly fixed the Liujia pump, and will test it and return it tomorrow.
The pump seems to be working fine. I just ordered a 12 V pump to make a comparison.