User Manual

PowerOptimal Elon® 100 User Manual
Version date: 2022/06/28
Page 14 of 24
Version number: 2.15
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4.3 Payback period
As can be seen from the graph above, payback period decreases as number of solar panels increases,
and is also different for Johannesburg, Cape Town and Durban
3
.
The reason that payback period improves (decreases) as number of solar panels increases, is because
there are some fixed costs (such as engineering design & safety components) and some costs that do
not scale linearly with array size (such as labour, wiring, mounting kit costs, etc.).
3
Calculations based on actual Elon performance, assuming a 20% reduction due to non-optimal user behaviour,
an initial electricity tariff of R2/kWh and an annual electricity price increase of 8%.