Basic Solar Panel Installation Pinoy Guide

Today, you’ll learn the basics of solar panel installation in the Philippines. This guide will explain the important specifications so you can match solar panels with a solar charge controller and decide whether to use a series or parallel connection.

We will dive into everything you need to know to get started with solar panels.

Power Rating (W)

Before installing solar panels, it is important to know the specifications of your solar charge controller.

The most critical detail is the maximum wattage it can handle. For example, if your solar charge controller has a maximum capacity of 1000W, you should not exceed that limit unless you are buying extra panels for backup or have the budget to spare.

The maximum wattage also helps determine how many panels you can install. For instance, with a 1000W controller, you can use ten 100W panels, six 200W panels, or two 500W panels.

The choice depends on your installation area. If your roof is weak, using several smaller panels, such as ten 100W panels, can distribute the weight more safely, although the efficiency may be slightly lower.

Short Circuit Current (ISC)

Short-Circuit Current (ISC) is very important when installing solar panels because it is used to size your wires and check compatibility with your MPPT charge controller.

For example, if your MPPT controller has a maximum of 11A ISC, you can connect two 100W panels in parallel with an ISC of 5.5A each, since the total will be close to the controller’s limit.

In a parallel connection, where you join positive to positive and negative to negative, the current values (ISC) add up.

In a series connection, where you join positive to negative, only the voltage increases while the current stays the same.If you do not calculate ISC properly, there is a risk of overheating or even fire, which may damage your solar panels or your home.

Always check that your wires and charge controller can handle the total ISC of your installation.

If you are unsure, consult an electrician, but you can also find helpful resources online to build confidence before installing your system.

WIRE Sizing

Proper wire sizing is essential for the safety and efficiency of a solar installation.

The wire size determines how much current can safely flow through the system without causing overheating or fire.

For example, in a 1 kW solar setup, you must first calculate the current that will pass through the wires. In a 12 V system, the current is 83.33 A (1000 W ÷ 12 V), while in a 24 V system, it is 41.67 A (1000 W ÷ 24 V). To ensure extra safety, multiply the current by 1.15 to add a 15% safety margin.

This results in 95.83 A for a 12 V system and 47.92 A for a 24 V system.

For a 12 V solar installation, you should use a THHN 90°C AWG #4 wire to safely handle 95.83 A of current. Remember, larger wires increase safety but also cost more.

Go here for reference: https://www.cerrowire.com/products/resources/tables-calculators/ampacity-charts/

Voltage at Maximum Power (VMP)

The voltage at maximum power is important in a solar installation because it affects wire sizing and the choice of solar charge controller.

Some solar charge controllers can accept inputs up to 500V at 11A (maximum 2000W), while others can only handle up to 50V at 100A (maximum 2000W). This means that a 500V controller allows you to connect your solar panels in series.

For example, ten 200W panels with 11A short-circuit current (ISC) and 40V each can be connected in series to produce a total of 2000W at 400V.

In this setup, you can use smaller THHN wires that handle 11A instead of thicker wires needed for higher current. In general, the higher the voltage, the smaller the wire size required.