System size, components and yield | SearchSolar Education

kW, kWp and kWh are not interchangeable

Unit	What it means	Example
W / kW	Power at a moment	1,000 W = 1 kW
kWp	Combined panel rating at standard test conditions	Six 570 W panels = 3.42 kWp
kWh	Energy over time	A 1 kW load for 3 hours uses 3 kWh

How system size becomes total production

Multiply the array's rated size in kWp by its net daily yield in kWh/kWp/day. SearchSolar's editable education calculator now starts at 3.8. At that planning value, a 3 kWp array produces about 11.4 kWh/day, 347 kWh in an average month and 4,161 kWh in a year.

The multiplier is a scenario, not a Philippine-wide promise. A net-yield value should already reflect conversion and system losses. If a source gives raw peak-sun-hours instead, apply the appropriate system losses once; do not subtract them twice. A site forecast should use the roof direction, pitch, shade, weather data and actual equipment.

3 kWp x 3.8 kWh/kWp/day
            = 11.4 kWh/day
11.4 x 30.4375 = 347 kWh/month

Why one system may produce for a longer part of the day

Solar panels do not share one universal on/off light level. As irradiance rises after dawn, a module begins making small amounts of DC power. Usable household AC starts only when the panel or string and inverter meet the inverter's start and operating requirements. The same process happens in reverse near sunset.

Panel designs differ in low-irradiance conversion, reflection, resistance and temperature behavior. A stronger low-light module can collect more energy in weak morning, late-afternoon or cloudy light. The inverter still matters: its start voltage, MPPT operating range, conversion efficiency and the way panels are connected can determine whether that small DC output becomes usable AC.

So 'activates earlier and deactivates later' can describe a real energy-yield advantage, but it is not a panel-only switch specification. Compare low-irradiance curves and temperature coefficients, then model the actual panel-and-inverter combination. The gain at the edges of the day is normally much smaller than noon output.

weak dawn light -> small panel DC output
                         |
        inverter start + operating range met?
                    yes  |  no
                         v
                  usable home AC

What is in a system?

Component	Purpose
Panels and mounting	Convert light to DC; secure the array to a structurally suitable roof.
Inverter or microinverters	Convert panel DC into household AC.
Combiner, wiring and protection	Collect circuits and provide the specified isolation, overcurrent and surge protection.
Monitoring and sensors	Measure generation and, with correct sensors, consumption and grid flow.
Optional battery and backup equipment	Store energy and supply selected loads during outages when designed and commissioned for it.

Generated energy is not automatically saved money

A unit of solar used by your home can avoid buying electricity. A surplus unit needs an approved export arrangement or usable storage; otherwise it may be curtailed. Compare useful energy, not just maximum panel output.

Sources and further reading

Official and manufacturer references checked 21 September 2026. Requirements and product terms can change.