Instruction Manual

PowerOptimal Elon® 100 Installation Manual
Version date: 2022/05/23
Page 28 of 37
Version number: 2.20
© PowerOptimal (Pty) Ltd 2022. The content of this document is confidential and all rights to the intellectual
property and/or information contained herein remain vested in PowerOptimal, except if otherwise agreed in
writing.
Appendix D. PV array and geyser (water heater) element matching
It is important to match PV array specifications and heating elements for maximum power transfer
efficiency. See the below table for the recommended heating element power rating for different solar
array sizes.
Contact PowerOptimal for advice on module-element matching if module properties are significantly
different to typical values or for advice on bifacial, high current & high voltage modules.
TABLE D1. GUIDE: PV ARRAY AND GEYSER (WATER HEATER) ELEMENT MATCHING
Solar PV array size
(kW
p
)
Best matching
geyser element size
(kW)
2
nd
choice geyser
element size*
(kW)
Geyser (water tank) size
(litres)
1 – 1.2
4
3
100 - 200
1.2 – 1.6
3
4 or 2
100 - 200
1.6 – 2
2
3
150 – 300
2 – 4
(two parallel PV strings)
4
NA
200+
* Second choice element size would reduce efficiency by 10 – 20%.
DO NOT DEVIATE FROM THE RECOMMENDED MODULE-ELEMENT MATCHING CONFIGURATIONS
WITHOUT CONSULTING POWEROPTIMAL.
Maximum allowed solar PV array specifications at Standard Test Conditions (STC):
I
sc
< 20A V
oc
< 240V Power < 4 kW
p