Guidebook – sunlight pump – ennos AG
Date:
18.01.2017
Page
9 of 32
copyright
ennos 2017
Sizing of the PV array
5.1
Solar Irradiance to be expected
The power output of the PV array depends mainly on the irradiance and the array temperature. A 80W panel might
give you 80W output in the test lab at 25°C and with 1000W/m
2
. In the field you will experience temperatures that
are more likely close to 60°C which will make the power output drop by already 20%.
Due to factors like dust, smog/mist, dirt on the panel, etc. the irradiance on your panel is expected to be lower than
1000 W/m
2
most of the time.
5.2
Sizing of the PV array
The sunlight pump comes with the best pumping performance currently available. This means that fewer solar
panels are necessary to reach a given water output compared to other system available on the market. And this
translates into lower initial investment costs.
The graph below can be used for optimizing the system performance while keeping the solar panel within
economical boundaries.
To calculate the required panel size you need the following two parameters:
•
Pumping lift in meter (suction head and lifting head equals total head) and
•
Desired water flow in liters per minute
Solar Power to Water Efficiency as a function of total pumping head and water flow
