SolarKrasibCalculate

5 kW vs 10 kW solar: which size fits your home?

Compare 5 and 10 kW solar using daytime demand, roof space, energy estimates and panel count.

Edited by SolarKrasibUpdated 28 September 2026Read4 min

The answer first

Do not choose 5 or 10 kW from the bill amount alone. Check loads that coincide with sunlight and roof space. A larger system can create more surplus without proportional bill savings. Export revenue requires a valid agreement and eligibility.

kW, kWp and kWh

kW measures instantaneous power; kWp is panel power under rated test conditions; kWh is energy. A 1 kW average load over 4 hours uses 4 kWh. Inverter and panel ratings may differ, so read both in the quote.

Illustrative production, not a guarantee

Assuming net yield of 4 kWh/kWp/day, 5 kWp produces 20 kWh/day and 10 kWp produces 40 kWh/day before additional shading and degradation. These are arithmetic examples, not a site survey or daily guarantee. Generation is not the same as energy used directly at home.

Panel count and roof space

For example, ten 550 Wp panels total 5.50 kWp; nineteen total 10.45 kWp. Actual roof space depends on panel dimensions, setbacks, maintenance access, structure and shade. Have the installer check string voltage and inverter ratings before finalizing panel count.

Supporting sources

  1. European Commission — PVGIS ↗
  2. U.S. DOE — Homeowner’s Guide to Going Solar (general principles) ↗

General information for questions and preliminary estimates. Site and contract conditions need individual verification. International sources explain principles, not Thai law.

Try this in the calculator