A quick look in things to know before going Solar

Solar Photovoltaic (PV) energy is quite a hype in recent world of renewable energy. We know it convert sun’s light energy into electrical energy. With current technology, we can power up cities and villages with just Solar PV alone.

So how you going to start a solar PV system ? What you should know before you even install them. Lets find out in our General Guide on Solar Photovoltaic.

Table of Content:

Related Article: Photovoltaic – Harvesting the Power of the Sun

Below is some of the infographic of our Solar Photovoltaic Guide. These general guide if for your referrences only on considerations that you may face or make when going Solar Powered ! Have fun and support our cause for green renewable power generation !

Going Solar Chapter 1: Know your Sun

A basic anatomy of the sun.


Going Solar Chapter 2: Know your Earth

The Solar Radiation Spectrum showing the spectrum at the top of atmosphere and at sea level. Noted that many missing wavelength from the final spectrum seen at sea level due to absorption by the Ozone, Oxygen and Water in the earth’s atmosphere.


The Global Solar potential.
Source: SolarGIS © 2014 GeoModel Solar


Going Solar Chapter 3: Know the sun’s movements


The Axial Tilt of Earth and its effect on the Earth’s seasons.


The Solstice and Equinox. If we look at Earth from a fixed axis, the sun appears to rise and set at different location throughout the year.


Going Solar Chapter 4: Know where to face your solar PV panels


This image illustrates the majority sun directions in a year with regards to different location on Earth.
The sun path during summer and winter at northern hemisphere.


Going Solar Chapter 5 : Know Your Sun Hours


“Peak Sun Hours” refers to the solar insolation which a particular location would receive if the sun were shining at its maximum value (1 kW/m2) for a certain number of hours. The longer the Sun Hours, the more potential for solar PV power generation.


Going Solar Chapter 6 : Know Your Solar PV System


A Simple Solar PV system comprise of Solar Panel, Charge Controller, Battery and a Load.
A simple Grid-Tied Solar PV System comprise of Solar PV panel and a Grid-Tied Inverter. Since the Grid-Tied Inverter can synchronize the output with voltage slightly greater than the voltage of the grid, the load can use the power from the solar PV system first before the main grid. If there is extra power it will be supply directly to the main grid.


A hybrid solar PV system is also a on-grid solar system with battery storage. There is several variant of hybrid system. Basically the battery can be charge via solar or from the grid and supply to the load when needed.


Going Solar Chapter 7 : Know Your Load

Illustration on how to estimate the size of your solar PV system. It is all back to your load, hence load calculation is an important part of a off-grid solar PV system.


Going Solar Chapter 8 : Know Your Solar PV Cells and Panels

Mono Crystalline, Poly Crystalline and Thin Film solar PV. Mono Crystalline solar cells have a characteristic of pure smooth looking with a cut off edge. Poly Crystalline have a speckled crystalline look. Thin Film is usually seamless smooth surface and some are flexible.

More information about each cell types can be found in our another article: Photovoltaic – Harvesting the Power of the Sun.

The difference between single junction and multi junction solar cell.
Showing how the two cells perform in converting the full spectrum of sunlight into electricity. In single junction silicon solar cell can accept photon with energy level more than 1.12eV, any energy more than 1.12eV is wasted as heat. In multi junction solar cell, different semiconductor can harvest photon of different energy level, hence increase the total efficiency.
The Current-Voltage Curve and Power-Voltage Curve of a solar PV panel.
A typical 36 cell and 72 cell solar PV panel. Other variant are also available including 32, 48, 60 cells.


Going Solar Chapter 9 : Know Your Solar PV Cells performance under the heat


The efficiency of Solar PV Panels decrease as their temperature increases, decreasing their overall power.


Going Solar Chapter 10 : Know the effect of partial shading

Partial shade can significantly reduce the power generation from your panels, hence look hard for all potential objects that can cause partial shade. A growing tree beside the house is often overlooked.
When there is a partial shading, even a single solar PV cell, the whole module output is affected. It is usually improved with placing a bypass diode that channel the current from the section with all unshaded cell away from the section with partial shaded cell.


Going Solar Chapter 11 : Know Your Solar PV Panels Mounts and Supports

A basic Solar Panel Mounting Frame. It can be fix mount on a roof or on a ground with a footing.


Single Axis Solar Panel design can be of Vertical or Horizontal Axis.


Dual Axis Solar Panel design can be simple dual axis (gear motor or actuator), Dual axis in a frame, dual axis on a rotating base.


Going Solar Chapter 12 : Know Your Solar Wiring


A general guide on wire gauge vs supported amperage and distance. The longer the wire, the bigger the diameter of wire is needed to prevent the resistant of the wire causing significant voltage drop.


Going Solar Chapter 13 : Know when to go series or parallel solar PV array

Solar PV panels in series or string configuration. It will have effectively a 144 solar PV cell string.
Solar PV panels in parallel configuration. It will have effectively a 36 solar PV cell string in parallel configuration.
Mixing solar PV panels in both equal series and parallel configuration can increase voltage and amperage at same time.


Going Solar Chapter 14 : Know Your Solar Charge Controller

You still can charge a battery directly from a solar PV panel without a charge controller, but you won’t get the full potential out of the system and yet risk of overcharging and damaging the battery.
The Charge Controller will decide the charging stage and hence deliver accurate voltage and current to the battery. This prevent overcharging that can damage the battery.


In PWM (Pulse Width Modulation) Charge Controller, the main purpose of the charger is to make sure the voltage is safe for charging of the battery, hence higher voltage that is output from the panel is usually wasted.
A basic concept on how Maximum Power Tracker works by targeting the maximum power point and convert the voltage and current accordingly to prevent excessive power loss.


PWM charge controller can handle solar panel voltage (eg. ~12-21V) which is similar to the battery voltage (eg. ~ 12V) , hence it is usually used in smaller solar PV system with panels optimized in parallel configuration. However MPPT charge controller can handle higher solar panel voltage ( up to 150 V) and hence can support many panels in serial configuration.


Going Solar Chapter 15 : Know Your Battery


The basic terminology you will encounter in battery storage. State of Charge, Depth of Discharge, Round-trip efficiency and Self Discharge Rate.
An Illustration of an example of cycle life of a battery (flood lead acid vs lithium ion battery) and the effect of Depth of Discharge on the Cycle Life.
Placing the battery in series will increase the voltage rating, while parallel configuration will increase the Amp Hour rating but the voltage remains constant.
This illustrates how to scale up your battery banks with combination of parallel and string configurations.


Congratulation if you had read until here. The list is non-exhaustive and more detail informations in the subsequent articles. Enjoy reading !