We are using power voltaic (PV) array to collect sunlight and generate energy to run the water pump. The water is stored in an elevated reservoir, and then fed to the crops by drip irrigation using gravitational force.
Basic demonstration
OSHNIC Solar panel.
Sizing solar pumps:
The hydraulic energy required (kWh/day)
= volume required (m³/day) x head (m) x [water density x gravity / (3.6 x 10^6 )]
= volume required (m³/day) x head (m) x 0.002725
The solar array power required (kWp)
= Hydraulic energy required (kWh/day)
Av. daily solar irradiation (kWh/m²/day x F x E)
where F = array mismatch factor = 0.85 on average and E = daily subsystem efficiency = 0.25 – 0.40 typically
Relation:
An acre of corn gives off 4000 gallon of water (~ 33000 lbs) in evaporation per day.
Imagine walking a quarter of a mile and carrying 50 lbs of water for 660 times a day to replenish the water loss!!!
Concerns:
- Training
- Maintenance
- Consider vertical integration
- Cultural changes
- Material sourcing (would like to keep as local as possible)
- Fencing
Source:
How much sun does Ghana have?
System demonstrated by Stanford team
How to calculate water volume pumped by solar power.
How much water is needed to…