Question 1

What is PSH (Peak Sun Hours)?

Accepted Answer

It's a measure of the solar radiation available in an area, equivalent to the number of hours per day the sun would shine at maximum intensity (1,000 W/m²). It varies by geographic location and the panels' orientation/tilt; check a solar radiation map for your area for a more precise figure.

Question 2

What is the performance ratio?

Accepted Answer

It's the percentage of the energy generated by the panels that actually ends up being usable, after losses from the inverter, wiring, panel temperature, and dirt. A value between 75% and 85% is typical for residential installations.

Question 3

Does this calculator account for batteries or surplus energy?

Accepted Answer

No. It's a simplified estimate of the number of panels needed to cover your average consumption, without modeling the mismatch between generation and consumption throughout the day, storage batteries, or surplus compensation schemes.

Question 4

How many panels do I need to cover 100% of my consumption?

Accepted Answer

The number this calculator gives already targets the stated daily consumption; in practice, without batteries, a solar installation rarely covers 100% of real consumption because nighttime use doesn't line up with solar generation. Many installations are sized to cover 50% to 80% of annual consumption, not 100%.

Question 5

Do I need to orient the panels exactly south?

Accepted Answer

South is optimal in the northern hemisphere, but southeast-to-southwest orientations only lose 5-10% of generation. A pure east or west orientation loses more, between 15% and 20%, and should be offset with more panels.

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