How to Setup a 250W Solar Inverter | DIY

Hey, in this post, I’m going to show you how to make a simple off-grid DIY solar power system and kickstart your off-grid living. Solar energy is amazing, and according to statistics, solar radiation that reaches the earth is enough to satisfy the energy needs of the planet. We have to develop better batteries and solar technologies to make this happen. 

The reason why we are not giving much attention to solar energy is because of the easy availability of high energy-dense, easy to deal with fossil fuels. But they are a limited, exhaustible source of energy. And burning fossil fuel releases carbon dioxide into the atmosphere, which is said to be the main reason behind global warming and climate change.  

You may also like: Grid-Tie Solar System can Drastically Lower Your Electricity Bill

We must go Green. It’s the need of the hour. New Physicist has a vision. 100% Renewably Powered Planet Earth. It’s just the beginning. I’m taking this chance to thank each and every inventors and engineer who contributed to the renewable energy industry. let’s get started with the project.  

Off-Grid DIY Solar Power System

An off-grid solar power system is a stand-alone system that generates electricity from solar energy to satisfy all the energy needs of that property where it is installed. So this kind of system is most suitable for remote areas where grid connectivity is not available. 

Sizing of the Off-grid diy solar power System

The first step to set up an off-grid solar system is to figure out your daily power consumption. I’m gonna make a diy solar inverter for my office.

My office has the following components.  

a.     10W Led Bulb 1 Nos for 4  Hrs  = 40 Wh

b.     50W Laptop    1 Nos  for 3 Hrs  = 150 Wh

c.      50W Fan         1 Nos  for 1 Hrs  = 50 Wh  

Total power consumption per day       = 240 Wh  

Battery Sizing  

Power Consuption Per day/Volatahe  = 240Wh/12v = 20Ah

DoD of battery 50%

So Required Battery Size        = 20Ah*2 = 40Ah

Solar Panel Sizing  

Power to completely charge the Battery

40Ah*12= 480 W / 0.85(loss) = 560W = (550)

We need a 560W solar panel to completely charge the battery.

In India, we have total PSH peak solar hrs nearly 5.5

so, Required Panel Power = 550 / 5.5 = 100 W 

Inverter Sizing  Total load connected   = 240 W

So any inverter rated more than that can be used. Here I chose a 400 VA Inverter

Components of an Off-grid DIY Solar Power System

There are four main components to make an off-grid solar power system. They are Solar panels, batteries, charge controllers, and inverters. And you need other components to connect these components together and tools to make that happen.

Solar panel 100 W

Silicon-based solar panels are the industry’s favorite. I bought 2 fifty watts solar panels from Amazon and it is manufactured by loom solar. This one is a monocrystalline solar panel.  To know more about mono and polycrystalline solar panels read this post How Crystalline Silicon Solar Cells are Manufactured?

Charge controller 10A

Charge controllers are used to protecting the battery from getting overcharged or over-discharged. There are two types of charge controllers in the market. They are MPPT and PWM charge controllers. I bought a 10A PWM charge controller, for small systems like this it’s enough. But MPPT charge controllers are more efficient.       

Battery 40Ah

  The solar battery is where energy is stored for later use. the main disadvantage of solar energy is that it is intermittent. So obviously we need backup o support our energy needs at those time. I bought a 40Ah tubular battery.  

Inverter 400VA

Most homes use alternating current (AC) energy, not DC, so the energy produced by your solar panels isn’t useful on its own. An off-grid solar inverter’s only purpose is to convert the DC output of the battery/solar panel to 230 V AC.  

Other Components You need to make an Off-Grid Solar Power system.

10 AWG wire, isolators, or circuit breakers. Board for a panel, Switch boxes, GI pipe

Tools You need to DIY solar power System  Welding machine, angle grinder, drilling machine, crimp tool. Other electrical tools    

Step1: Fix Your Solar Panel Perfectly First 

Sun has two movements in the sky. One is east to west daily movements. and the other is south to north seasonal movements. To get the maximum power out of the solar panel the angle of incidence of solar radiation on the solar panel must be 90 degrees. That’s why we use dual-axis tracking to move the solar panel automatically to face the sun. Here I’m making a single axis manual tracking framework to track suns seasonal movements.  

Step 2: Connect Solar Panels in Parallel

I bought 2 50 watts Solar panels. Since I’m building a 12 V system iv to connect these panels in parallel so that I’ll get an output of 12v 5A maximum.   

Step 3: Make Control Panel

A Control panel is a must. So that we can easily connect the components and manage the connections and avoid any failures. If there any fault we can easily understand if all the components are neatly connected.   

Step 4: Connecting Components

Use isolators to separate individual components of an off-grid solar system. and you must be cautious about the wire gauge especially the wire from the solar panel to the control panel. There are websites you can easily figure out the option wire gauge by entering the total wire length and maximum current flow.  

Step 5: Testing Project

When you turn the off-grid solar power system on, always turn the battery isolator ON first, then the solar panel. not vice versa. That’s it Our Solar Power system is working perfectly. The charge controller shows  21.5 V on a high-intensity sunny day.     

Now is the time to turn on the entire system. Keep in mind that, always turn on the battery circuit breaker first. Then turn on the solar panel isolator. Then you can see in the charger controller display the symbol of solar panel, charge controller, which implies the solar panel is now charging our battery. Now you can turn on the inverter or just use DC loads.

This battery can be discharged up to 20Ah, which means it can power up to 20*12= 240W equipment for one hour or a 10W bulb for 24 hours. Cool. Enjoy your own off-grid system. If this DIY article is helpful consider sharing it with Thank you. your social media profiles and support my mission to build a better, sustainable tomorrow!