On-Grid, Off-Grid or Hybrid Solar? How to Choose the System and Size (2026)

Most people start by asking how many panels they need.

Step 1

The Three System Types

They differ mainly in whether they connect to the grid and whether they include batteries.

Panels feed a grid-tie inverter that runs in parallel with PEA or MEA power.

Best for: lowering the electricity bill where the grid is reliable.

Watch out: no backup power in a blackout.

Panels charge a battery bank through a charge controller and inverter.

Best for: places the grid cannot reach.

Watch out: needs a large battery bank.

A grid-connected system with a hybrid inverter and battery added.

Best for: sites with frequent outages or critical loads.

Watch out: costs more than on-grid.

Quick Chooser

Find the line that sounds most like your situation.

1
The goal is a lower electricity bill and the grid is reliableChoose On-Grid.
2
Blackouts happen and some equipment must keep runningChoose Hybrid.
3
There is no grid connection at the siteChoose Off-Grid.
4
You want to store solar for evening useHybrid can do it.

Step 2

Work through these five checks in order. The smallest limit wins.

1
Know your usageCollect 6 to 12 months of electricity bills.
2
Size to daytime use, not the whole billSolar only produces while the sun shines.
3
Check the roofAllow roughly 6 to 9 m² of usable roof per kWp.
4
Check program limitsThe household buy-back limit is 5 kW (AC) per meter.
5
Size the battery (Hybrid and Off-Grid only)List the loads to keep running.

Worked example (illustrative) A home with a 5,000 baht monthly bill.

Avoid These

This article is general guidance.

Tell us how you use power and what you want the system to do.