DIY Guidance: How to Build Your Own Solar Generator

The best time to switch to green energy is today. Given the rising global issues with climate change, it’s risky to keep relying on fossil fuels to sustain our lifestyles. And thankfully, we live in an era where solar energy is affordable like never before.

What a time to be alive.

Solar generators are power banks for individuals who require charging beyond cellphones and pocket WiFi. We know solar energy might still be a “futuristic” concept for some households out there, but truly, having accessible, usable energy on the go is something we all need—and it doesn’t have to break the bank. This article will give you the information you need to build your DIY solar generator. We will walk you through the following:

  1. How to determine the size of a DIY solar generator for your situation;  
  2. What materials do you need; and
  3. How to put them all together;

What is a Solar Generator?

Before you create a homemade solar generator, it is best that you understand what it means and how it works.

The best way to do this is by breaking the term down word by word.

So, what do we get? “Solar” and “Generator.”

Let’s start with the word “Generator.” In power systems engineering, generators are machines that convert one form of energy to electric energy. That’s why we have a variety of them, such as fossil fuel, natural gas, hydro, geothermal, and wind, to name a few.

On the other hand, the term solar means “about the sun.”

Putting those words together, we can deduce that a “Solar Generator” is a device that can take in solar power and convert it to electricity.

solar generator

The Problem with Solar

However, more experienced readers right now might be thinking:

“That’s just the gist of it! There’s more to it than that, right?”

We agree with you 100%. As a green energy warrior, the more you go down the road of solar, the more you realize that it has many limitations as a sustainable technology.

For example, one of the early problems with solar electricity is that you must use it as you produce it.

If we are to magically wave our wand and eliminate all the fossil fuel generators now, where do we get our electricity at night or if a cloud goes over our solar panels?

The Solution: Storing Solar Energy and More

That problem was one of the fundamental hurdles solar developers had to solve at the onset of the clean energy era.

This led to the development of the modern energy storage system (ESS), which is essentially the enhanced version of car batteries.  

Having energy storage systems combined with a solar panel allows its users to harvest solar energy, store it, and use it for emergencies, during nighttime, or in situations when the sun isn’t as available.

From what we shared, you should realize by now that solar developers and policymakers are building a sizeable chunk of the green energy movement around solar technology. One of the main reasons for this is that solar power harnesses energy from the sun, making it a truly sustainable source of energy compared to the other variants. Aside from ESS, many other technologies are used to create solar generators, such as inverters, battery management systems, etc.

DIY Solar Generator Functions

Based on what we discussed, we can discern that essential solar generator operation involves harvesting, storing, and converting solar energy to electricity.

In addition, modern solar generators have other functions, such as battery protection and portability.

With these features in mind, let’s begin the DIY solar generator process by creating a master plan.

Planning Your DIY Solar Generator

A well-planned DIY solar generator comes with many benefits. Starting your DIY process with planning creates order in your workflow. It also helps you reflect on your goals and needs. From a financial perspective, knowing exactly what you want from your DIY solar generator will save you a lot of money.

For example, knowing the maximum electric power and energy, you need for your devices will help you avoid excessive spending on oversized batteries and inverters.

Table 1: Sample Price Comparison of Inverters by Size and Quality

Inverter Size

Pure Sine Wave (Good Power Quality)

Price (Pre-tax)

500 Watts

No

$45

750 Watts

No

$65

1000 Watts

No

$80

1000 Watts

Yes

$140

2000 Watts

No

$170

2000 Watts

Yes

$260

3000 Watts

No

$300

 

Estimating Energy and Power Needs

Estimating your energy and power needs can be done through the following steps:

  1. List down your devices
  2. Determine the continuous power ratings of each appliance
  3. Gauge how long you will use each device daily to assess your energy needs

1. Write Down All the Devices

The first step is straightforward: List all the devices you wish to run through a solar generator. We understand that you have many electronics you want to power, but recall that the higher your power needs, the more expensive your solar generator project will get.

Therefore, we recommend limiting your devices to essentials or particular activities, such as backup power for your work-from-home setup or meal preparation appliances in the RV.

Table 2: Sample List of Appliances for Your Home Workstation

Devices / Appliances

Laptop

Cellphone

Internet Modem

Monitors x 2

LED Lamp

 

Table 3: List of Appliances to Prepare Meals in an RV

Devices / Appliances

Electric Stove

Coffee Maker

Microwave

Toaster

Mini Fridge

 

2. Determine the Power Ratings of Your Devices

Next, we need to know how much power you will need if you will turn all your devices on together.

Electronic devices usually come with a label that shows their power ratings.

Table 4: WFH(Work from Home) Total Power Needs

Devices / Appliances

Power

Laptop

150 Watts

Cellphone

15 Watts

Internet Modem

300 Watts

Monitors x 2

60 Watts

LED Lamp

15 Watts

Total

540 Watts

 

Table 5: RV Total Power Needs

Devices / Appliances

Power

Electric Stove

1,500 Watts

Coffee Maker

600 Watts

Microwave

1,200 Watts

Toaster

500 Watts

Mini Fridge

110 Watts

Total

3,910 Watts

 

3. Assess Your Energy Needs

Table 6: WFH(Work from Home) Power and Energy Needs

Devices / Appliances

Power

Time Used

Energy

Laptop

150 Watts

4 hours

600 Watt-hours

Cellphone

15 Watts

16 hours

240 Watt-hours

Internet Modem

300 Watts

4 hours

1200 Watt-hours

Monitors x 2

60 Watts

4 hours

240 Watt-hours

LED Lamp

15 Watts

8 hours

120 Watt-hours

Total

540 Watts

 

2400 Watt-hours

 

Table 7: RV Power and Energy Needs

Devices / Appliances

Power

Time Used

Energy

Electric Stove

1,500 Watts

0.4 hour

600 Watt-hours

Coffee Maker

600 Watts

0.1 hour

60 Watt-hours

Microwave

1,200 Watts

0.1 hour

120 Watt-hours

Toaster

500 Watts

0.1 hour

50 Watt-hours

Mini Fridge

110 Watts

24 hours

2,640 Watt-hours

Total

3,910 Watts

 

3,470 Watt-hours

Note: Energy (Watt-hour) is Power (Watt) multiplied by time (hour)

Based on our sample planning process, you will need 3,910 Watts and 3,470 Watt-hours per day for your RV meal preparation setup. On the other hand, your work-from-home setup needs 540 Watts and 2400 Watt-hours daily.

We realize that the items and ratings in our sample tables will likely differ from your cases. Feel free to create your personalized table before proceeding to the next section.

Gears and Components for Your DIY Solar Generator

Visual aids are perfect for helping people get an overview of a topic. It will also help you create order and retain information throughout this article.

That being said, let’s examine the blueprint below. Based on the image, we can summarize the components we need for your DIY solar generator, such as:

  1. Solar Panel (Portable if needed)– A device that converts solar energy to electric DC energy;
  2. Solar Charge Controller (PWM or MPPT)– A device that charges and protects your battery by controlling the voltage, current, and power input from solar panels;
  3. Battery (12V and Lithium-ion)– A device used to store solar energy;
  4. Inverter– A device that converts DC power from either solar panels or batteries to AC power used by common household appliances;
  5. Wires, Terminals, and Adapters– Parts of a solar energy system used to connect the four main components mentioned above;
  6. Fuses– An optional (but highly recommended) protection device that disconnects your solar energy systems during dangerous situations
  7. Enclosure– An item that makes your DIY solar generator easy to carry. After all, it would save you much stress if you have something that holds everything together (except the solar panel).

 

diy solar generator

Figure: A DIY Solar Generator Blueprint. Image reproduced from Portable Solar Power.

Matching the Ratings of DIY Solar Generator Components

Now that you have an idea of the primary components of your DIY solar generator, let’s ensure they are all compatible. Note that when we say “DIY,” it doesn’t mean building the components from scratch. Rather, it means being able to assemble the parts that are compatible with each other in accordance with your energy needs and budget.

For starters, you should determine if you wish to use a 12-volt or 24-volt system. For beginners, we recommend the former.

Ensuring all your solar parts are optimized is simply a matching type game: Make sure your inverter, charge controller, and batteries have higher voltage and current ratings than your solar panel.

Let’s take the following example.

Sample DIY Solar Generator Shopping List

Main Components

 

Item

Voltage

Current

Power/Energy

Portable Solar Panel

20V

10A

200W

Charge Controller

100V

20A

12V/260W, 24V /520W

Battery

12V - 14.5V

80A

1200Wh

Inverter

12V

- 

1000W continuous/ 2000W peak surge on start-up

 

The buying process starts with solar panels in our sample component list above.

Now, using our sample work-from-home setup, a 12-volt system should suffice, beginning with our solar panel with a 20-Volt and 10-Ampere input.

Using the power formula, 20V multiplied by 10A equals 200W.

Let’s move on to our battery component.

Given that our battery only accepts 12V to 14.5V, the 20V input from the solar panel is too much.

This is where the solar charge controller comes in. The MPPT charge controller we selected takes in the 20V and 10A from the solar panel and regulates it to 12V while maintaining the 200W power injected into the battery. Pretty cool, right? MPPT does increase solar system efficiency compared to PWM.

Related: MPPT vs. PWM Charge Controllers: What's the Difference? 

From here, it is smooth sailing. Just attach a 12V inverter to your battery, and you already have the bare requirements to operate a DIY solar generator. Given that our sample setup includes sensitive gadgets, we recommend using a Pure Sine Wave Inverter.

Connectors and Enclosure

Electrical wires and fuses are invaluable in linking the main components together while ensuring safety. We recommend using 30A fuses, a 4AWG wire for your battery-inverter connection, and 12 AWG for the rest.

homemade solar generator

Figure: MC4 adapter (left) and Fuse (right)

We recommend using a shockproof hard case to protect your sensitive equipment from impact for the enclosure.

Related: Uninterruptible Power Supply: Does Your Solar Generator Have One?

build solar generator

Figure: An industry-grade hard case.

Putting Together Your DIY Solar Generator

After all the planning we have done, all that is left is to put these things together. If you are not confident with your assembling, drilling, and installation skills, there is no shame in hiring an expert handyman or electrician to do the work for you.

  1. Install the battery and inverter in your case

Often, batteries are the most significant components of a DIY solar generator. Therefore, placing them first inside your enclosure is a good idea. If you buy a suitcase-like hard case, put the battery at the bottom, wheel-end side.

Lastly, hold the battery in place using industry-grade clamp-down straps. Next up is the inverter. Place it in a position that allows some space for you to insert the cables coming from the battery and the devices.

You can also cut a hole in your hard case to make the outlets and USB more accessible. However, you risk exposing your sockets to the elements, such as rain, snow, etc.

  1. Install the solar charge controller

Lastly, install the solar charge controller inside the case and hold it down using the same clamp straps.

Recall that the solar charge controller connects the solar panel to the battery. Therefore, you should install MC4 adapters into your charge controller if they aren’t included in your purchase. These adapters will connect your solar panel to your charge controller.

 

MC4 Adapters going into the charge controller

MC4 Adapters going into the charge controller

  1. Install the Wiring and the Fuse

Now that we have finished installing our three main components, it is time to wire them up, as illustrated in our blueprint/wire diagram above.

Remember that there should be active connections between the following:

  1. Solar panel and charge controller
  2. Battery and charge controller
  3. Batter and inverter

Related: How to Wire Solar Panels for Solar Power Generator - An Ultimate Guide

Final Thoughts

There you have it! The basics of making a DIY Solar Generator. We understand that first-timers like you might have more questions as you make this complicated setup. Reach out to us if you have any concerns or clarifications, and we will gladly help you!