The Beginners Guide to Off-Grid Solar

When Chris and I began our journey into the world of resilience and off-grid living, one of the most significant issues we tackled was getting energy on our homestead. We had trials and our fair share of errors, but we managed to create a system that fits our needs. The hardest part in the process was not having a single resource that told us how to go from a solar panel to being able to turn on a light in our home. Sure, tons of resources explain what solar panels are and how to set them up, but a lot of these resources are not geared toward those living on the outskirts of the law.


Electrical codes are on the books to make a safe and healthy environment for inhabitants of a dwelling. The problem some off-grid folks face is not wanting an inspector or agent of the government anywhere near their property. This is where I step in. I am by no means an expert in electrical engineering — but I have had a fully functioning solar-powered house for almost three years. In saying all of that, I'd like to make the following disclaimer:

"I am not an expert in anything electrical. I am showing you how I set up my solar panels easily and safely. I would not recommend anyone follow any of these steps to set up their own off-grid solar array. It would be a shame if you did this, and the government had no idea that you could live off the sun's energy and not pay ridiculous amounts of money to energy conglomerates. Definitely don't follow any of the following steps."


But First, Some Housekeeping


If you are new to the world of electricity, it might be nice to understand some of the terms I will be using in this article. My goal is to make this as painless as possible.


Amp: Amp (A) is short for Ampere. Amps measure the amount of electrical charge flowing past a given point in one second. Simply put, amps measure how much of an electrical current is being drawn through power cables.


Volt: Volts (V), short for voltage, measures how strongly electricity is being pushed through a circuit—the amount of volts tells you the amount of pressure being exerted.


Watt: Watts (W) or wattage measures the amount of electrical power a device uses.


Simple math: W=AxV


The how-to diagram


I spent countless hours scouring the internet, searching for a complete diagram to show how to go from the panels to an outlet. I found some that were mostly good, but none of them gave me all the answers I was seeking. So, for myself and this guide, I created my own. I hope it helps you as you embark on this endeavor.



Diagram of a solar-powered energy system

Step 1: Figuring out your energy consumption needs


The average energy consumption in the "typical" U.S. household is around 10,000kWh a year. That number is entirely ridiculous. If you are serious about taking your life off-grid, you're going to have to lower your energy consumption. Hint: you don't need to have all your lights on simultaneously or during the day at all. Let's say you and your family are energy drainers, and you have to use 10,000kWh a year — you'd be looking at needing 19 (300W) solar panels to run your household under the best conditions. That would run you approximately $6000 (not including tax and all that other shit). If you've got that kind of money, go for it!

Chris and I have 8-300W solar panels that produce 12,000W of power daily with an irradiance of 5 peak sun hours. The panels and battery bank that we have take care of all of our energy needs, and we are probably a little too conservative with the power. I don't like to have more than one light on in the house after the sun goes down (just ask my partner). You have to be careful because you don't want to run into a situation where you run out of power and your batteries deep cycle.

Step 2: Solar Panels


We first started with 3-100W solar panels that we got in a kit from Amazon. They were of decent quality, but they don't draw nearly the amount of power we need for a household. Early last year, we switched to our current system from Grape Solar. You can order sets through Home Depot, which was incredibly convenient for us. Another great company to check out is Renogy. Again, you have to find the panels with the correct wattage for your needs.


Example of a mounted solar array

Another distinction that should be noted is between polycrystalline and monocrystalline solar panels. When it comes to efficiency, monocrystalline has a higher rating than polycrystalline mainly because it is made of one piece (i.e., mono). As a result, it can withstand higher heat for more extended periods. So do yourself a favor and go with the monocrystalline.

Step 3: Charge Controller

Where do you plug in your panels to produce usable electricity? A solar charge controller. The question is: what size charge controller do you need? Let me hit you with a little bit of math: take the number of panel watts (in our case 2400w) and divide that by the volts of your battery bank (ours is 120v right now, but we will talk about that later). You should then multiply this by 25% to allow for fluctuations from cold temperature and round up. You don't want too few amps for your system, leading to problems. The math looks like this:

2400/120 = 20 | 20x.25 = 5 | 20+5 = 25 amps — to give it a little wiggle room we would go with a 30 amp charge controller. The one that we currently have is the 30A MPPT charge control from EPEVER.

Example of a solar charge controller

You'll also see PWM and MPPT thrown around when looking at charge controllers. PWM is pulse width modulation, and MPPT is maximum power point tracking. MPPT devices are 30% more efficient than PWM, but they are also more expensive.


Step 4: Batteries


There are so many different types of batteries you could look into when storing the power from your solar panels. The two major styles are lead-acid and lithium-ion.


Flooded Lead-Acid (FLA): These batteries are inexpensive but require a fair amount of maintenance. Each battery cell must be submerged in water, and the water level needs to be maintained regularly, or you will run into unfortunate circumstances.

Sealed Lead-Acid: Similar to the FLA, except for these batteries being a closed system, they are slightly more expensive. However, no maintenance of the water level needs to be performed. Additionally, these batteries handle temperature fluctuation better than FLA.

Lithium-Ion: These batteries are the best on the market. They have longer lifespans, better efficiency, and no maintenance. The only downside, from my perspective, is the cost. For example, this lithium-ion 100ah battery from Renogy is priced at $722.49 (at the time of this writing).


Choosing the correct battery for your system depends entirely on how much money you budget for the project, how much time you want to spend on maintenance, and your system's overall use. For our system, we use a sealed lead-acid 100AH battery from Renogy. We currently have 12 in our battery bank.


Step 5: Inverter


This part is vital because there is a specific part that is crucial to how I've built my system, and if you are going to follow this method, you need to have a similar function. The terminal block is a part of the converter on the front of the machine. It has a positive, neutral, and ground. So what I did was run those wires from the inverter into the circuit breaker.


Solar inverter with a terminal block

The circuit breaker size is dependent on your system. You want to ensure you don't get too small or too large of an inverter. My system is 2400W. I could have gone with a 2500W inverter, but that would have been cutting it a little close. So instead, I have a 3000W inverter for our system.


Step 6: Circuit Breaker Box


Circuit breakers are a safety mechanism designed to "trip" when they detect the passing current exceeds their amperage. If they did not shut themselves off when confronted with a surge of electricity higher than their rating, they could disable your entire system. This would be a costly mistake, not to mention inherently dangerous.


When choosing your breaker box, you need to calculate the total amperage of your ENTIRE SYSTEM. Every appliance and lightbulb you intend to use must be considered in this equation.


Usually, most of the outlets and light switches in your house will be on either a 15-amp or a 20-amp circuit. If you have something like a washing machine or another heavy energy consumer, you will need either a 30-amp or larger. But how do you find out how much you need? Gather around:


  1. First, find the breaker that correlates to the electrical device you are using.

  2. Then, multiply the amperage by .08. This is because a circuit breaker should never exceed 80% of its max amperage. Not doing this could leave room for calculation errors, or even worse—an electrical fire. Example: 15x.08=12 — the maximum amount of amps you can have on your 15-amp breaker is 12-amps.

  3. Calculate the amperage draw of ALL the devices you wish to plug into the circuit by using the following equation for each and then add them together:

Amps = Watts/Volts


For example, a 200W light bulb on a 120V circuit would draw about 1.67 amps.


200/120 = 1.67


Below is an example of how to figure out what kind of breaker you might need for a specific room in your house. I chose the kitchen for convenience. First, list the appliances you plan to have on one breaker to see if they all fit comfortably under the 80% usage for the breaker in question.

Appliance/Watts

Equation

Total Amps

Electric kettle/1200W

1200/120=10

10-amps

Lamp/200W

200/120=1.67

1.67-amps

small radio/25

25/120=0.21

.21-amps

Total = 11.88-amps

While realistically you would be able to use a 15-amp breaker for all of these appliances at the same time, you are cutting it close. In this scenario, it is best to increase your breaker to a 20-amp or make sure you are not running all your appliances simultaneously.


After finding the total amps per breaker, you will need to add them together to find the total amps you need for your breaker box. For example, the total number you came up with for all breakers is 62-amps. In this instance, you will want to have a 100-amp breaker box like this one. Of course, there is always the possibility that you will need more than 100-amps, so plan accordingly.


Another choice you should consider is if you want a single-pole box or a double-pole box.


If you choose the single-pole, it's a relatively easy setup where you run the live (black) wire from the terminal block on your inverter to the first breaker in the system. Then, the neutral (white) goes to the corresponding neutral busbar.


The double-pole is slightly more complicated but manageable. In the first breaker slot of your box (on the left), you will place an 80-amp double-pole breaker, as shown below.



The next part is critical. You will need to put what's known as a "jumper" between the first and second breakers. The reason behind the jumper is to give power to the second pole. In a traditional house, the live wires that are the main power for the system are split between the two poles. In this model, you provide power to the first pole directly from the inverter and "jump" the power to the second pole. Below I have a drawn diagram of what this looks like in practice, as well as other key components of the breaker box.


I'm not going to go through the minutiae of explaining how to run wires or hook up an outlet; learning to do those is reasonably straightforward. However, if you are looking for an example of such a video, click here.


Wires


Yes, you need different wires for different levels of circuits. The different types of wires come with two numbers, for example, 14/2 wire. The "14" indicates the gauge of the wire, and the "2" shows there are two 14-gauge wires (live and neutral). However, you technically get three wires in the strand, but the ground is not counted. To make this as easy as possible, please consult the following table.

Circuit

Wire size

15-amp

14/2

20-amp

12/2 or 10/2

30-amp

10/2

40-amp

8/2

50-amp

6/2

Tools


An amateur electrical technician is only as good as their tools. While other tools are certainly helpful to get the job done, below, I've listed the tools you will absolutely need if you don't have them already. I'm partial to Kobalt, but many different companies make the same tools.

Necessary tools for the job

Tips and Tricks


  • ALWAYS check that your electricity is off BEFORE working on wires. I always check (and double-check) that my power is off before working on any outlets or wiring. Also, do not wear metal jewelry while working with wires. If the positive and neutral wires are live and come in contact with the metal—you can kiss your finger goodbye.

  • Plan out your wiring scheme and outlet placement before you start laying the wire. Think of every place you want an outlet or light switch and plan accordingly.

  • Have fun knowing that soon you're going to be completely off-grid while still having access to some of the creature comforts that only electricity can provide.

I hope you've found this guide helpful in your pursuit of a resilient off-grid life. There is something special about flipping a switch and knowing that you were the one who set up the system to make that switch work. While the cost upfront is substantial, the system pays for itself with all the money you don't have to pay to an electric company. As I've said before, but it bears repeating, please be safe when working with electricity. One little mistake could send you to the emergency room—or worse. So go slow and consult the guide or me with any questions you may have. I'll try to answer to the best of my ability.

If this information helped you, or maybe it might help someone you know; please give it a share!


 

An adapted version of this article can also be found at PeakProsperity.com