Tuesday, April 16, 2024

How To Build An Off Grid Solar System

Select Your Solar Panels

EASIEST Off Grid Solar Power System Battery Bank

When it comes to actually collecting energy from the sun, thats where solar panels come in. There are a few different solar panel options available to choose from.

Monocrystalline vs. Polycrystalline Panels

Choosing between monocrystalline and polycrystalline panels is one of the first steps to take when shopping for solar panels. Polycrystalline panels are light blue in color, and they are less energy and space efficient than monocrystalline panels. On the plus side, they are also the cheaper option. Monocrystalline panels, which are darker in color, are more space and energy efficient. Keep in mind that with the added efficiency comes a higher price tag.

Portable vs. Roof Mounted Panels

Rigid, roof mounted solar panels are the most common solar panel type and durable solar panel type. They are also ideal if you have consistent energy needs and want to be able to charge your battery bank at the flip of a switch. If you are looking to mount your solar panels on a non-flat roof, flexible solar panels are the way to go.

12V vs. 24V Panels

Learn more about all of this and more in the following posts about solar panels and how to select the right one for you.

Selecting The Correct Size Power Inverter Battery Cables

It is very important to be sure you are using the appropriate cable size for your inverter/battery. Failing to do so could lead to your inverter not supporting full loads and overheating, which is a potential fire hazard. Use this as a guide for choosing the proper cable size, and be sure to contact a professional electrician or our tech team with any additional questions you may have.

1. What size inverter do you have?

2. What is the DC voltage of your battery bank?

3. Now divide the inverters wattage by your battery voltage this will give you the maximum current for your cables.

Example Calculation

How To Build An Off Grid Solar System In 2022

Are you looking for a reliable solar system to use on your remote off grid cabin?

Whether youre seeking a self-reliant lifestyle or the ability to have power during a blackout, an off grid solar power system is for you!

Below, well include all the information you need to build your own in just a few steps!

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Determining How Much Energy Solar Panels Produce

As you might have guessed, the amount of power that your solar panel produces depends on how much sun they gets. That means during the shorter days of winter you will get less power. Also, cloudy days will give you much less power than sunny days.

Again, the best way to know how much power your solar panels will produce is to measure it. Buy one solar panel and measure how much energy you can produce throughout the year. Not every year is the same, so you will need to oversize your system just a little bit in order to account for usually dark or cloudy years.

However, you may just want to get a rough estimate of how much solar power your panels were produce. Luckily the US government has produced solar power availability data for the entire United States.

The map above shows on average how much power your solar panels will produce per day. The number depends on the color of your area it ranges from about two to eight. This number can be multiplied by the power rating of your solar panels to determine how much power they would produce. So if you live in an area labeled as three on the map and you bought a 1 kW Solar panel array then you would get 3 kWh of energy produced per day on average.

This assumes that you have full access to the sun so long as it is up. If location of your solar panels is partially shaded, especially during mid day, then you will get less power than the map shows.

Select The Amount Of Battery Storage Space You Require


Following that, you will need to determine how much power storage you require.

Do you want to be able to cover your usage for a single day, or want to have additional backup capacity available?

Generally speaking, when it relates to the solar battery backup, there is a rule that you will want enough storage to last at least 2 to 3 days during the busiest time of year for your solar system.

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Choosing The Right Solar Panels For The Job

If youre limited on space for your DIY solar project, monocrystalline panels are the best option due to their greatest efficiency and similar cost to their polycrystalline cousins.

Polycrystalline panels may be suitable if space is not an issue and youre trying to reduce costs even in small ways.

Thin films arent suitable for small-scale solar installation projects, nor are they worth it.

Calculate The Number Of Solar Panels Needed For Your Location And Time Of Year

The second half of our off-grid calculator can help you figure out how many solar panels youll need for your solar system. After knowing how much energy you need to make per day from the load calculator, youll need to tell it how much sunshine youll have to harvest from. This available energy from the sun for a location is referred to as sun hours.

The number of sun hours is how many hours the available sun shining on your panels at an angle throughout the day equals sunlight, as if it were shining directly on your solar panels when they get the most power. As you know, the sun isnt as bright at 8AM as it is at noon, so an hour of morning sun may be counted as half an hour, where the hour from noon to 1PM would be a full hour. And unless you live near the equator, you do not have the same number of hours of sunlight in the winter as you do in the summer.

You want to take the worst case scenario for your area, the season with the least amount of sunshine that you will be using the system. That way, you do not end up short on solar energy for part of the year. If its a summer camp, you dont need to plan for winter, but if it is a year-round home, or a hunting cabin, you need to tell it the number of sun hours that correspond to winter.

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Inverter And Battery Stand

I made the above inverter and battery stand by the help of a carpenter. The design idea I got from this instructable. The design is really helpful for me.

At the backside, I made a big circular hole just behind the inverter fan for fresh air suction from outside. Later I covered the hole by using plastic wire mesh. Few small holes are also made for inserting the wires from solar panel, charge controller and inverter to the battery and ac output to the appliances. At both sides panel, 3 horizontal holes are provided for sufficient ventilation. A glass window is provided at the front side to view the different led indications in the inverter.

In the inclined plane of the inverter stand, I have mounted the charge controller. In the future, I will install my own made energy meter also.

Generator Input & Charging

DIY Off Grid Solar Power System for Home – AMAZING POWER!

If you want to charge your batteries via a generator, simply run some 6/2 wire to the AC In-1 connection. Then connect the other side of the wire to a 30A plug. Note that were now in 3 wire territory. Black is Line, White is Neutral, and Green is Ground. Also know that youll need to change the charge settings for your generator input.

Our backup generator is a small Harbor Freight 3500W Predator. But Victron assumes youll be using something much larger. I think the default input current limit is upwards of 60A. Our generator puts out about 25A max, so we had to change this setting.

Unfortunately Victron doesnt make this easy. We had to do the dip switch dance – a very convoluted way to set your input current via tiny switches behind the top panel of the Quattro. I wont get into this here – youll have to read the manual carefully. But once it is changed youll see the number for Input Current Limit updated by going to Menu > Quattro Inverter on the Color Control GX.

Supposedly you can change this and some other settings by connecting the Quattro to your computer via an MK3-USB cable and software, but we havent tried it yet. Maybe one day.

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Designing A Diy Solar System That Meets Your Needs

The most important thing to know, when getting ready to build an off grid solar system, is how much energy you need, as well as how you energy usage changes throughout the day and year. Renewable energy systems are inherently variable, and therefore understanding daily and yearly rhythms of your familys energy usage is essential in planning an efficient system.

Getting this right will be a big portion of part one of this guide.

What Is Your Peak Power Demand

What are the electrical loads that you will need to run? Will they all run at the same time, or can you rotate the loads?

Your peak power demand is your total wattage usage when you are running all the electrical loads you need simultaneously. By staggering usage of major appliances at different times, you can reduce your peak power demand and bring system costs down.

Figure out how many appliances you expect to run at the same time, and add up their wattage consumption. The total is your peak power demand. Make note of this number, as well be using it to figure out your inverter size.

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What Are The Cons Of Solar

What are the drawbacks of going off grid?

If its so great, wouldnt everyone do it?

Here are some of the disadvantages.

High start-up cost: While batteries are increasing in efficiency and dropping in cost, going off grid is still expensive.

To do it, you need to install a large solar system that wont rely on any external grid power to keep the lights on.

This is generally a high start-up cost that most people cant afford.

Gas-powered generator required: People generally dont want to deal with the inconvenience of losing power at any point.

In the case of emergencies or system failure, most people will decide to purchase a backup generator for their homes.

This is yet another expense that can deter people from getting started.

What Is Your Nightly Kwh Usage


In the daytime, the power you use comes straight from your solar panels. When the sun goes down and panels are no longer generating power, the battery bank takes over and your appliances will run off of stored energy.

Using the same method as above, add up the appliances youll use at night and tally them here. Your fridge, TV, and smartphone charger are common appliances that run in the evening and overnight. Your inverter also has a self-consumption rating which should be accounted for.

Well-designed off-grid homes can use as little as 3-4 kWh per night, but yours may be higher if you want to run power-intensive appliances in the evening, like an HVAC system.

Tally up your nightly kWh usage and write the number down in your notes.

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How Do I Know If Going Off Grid Is Right For Me

There are both advantages and disadvantages to going with an off grid solar system.

If youre wondering if it may be worth it to you, read through the following list of criteria.

While these are in no way a requirement, they could help you determine if you would thrive in an off grid environment.

I live in a tiny home, cabin, RV, boat, or an isolated area

I want to be energy independent

I want to stop paying money for utilities

I live in an area without reliable, steady access to power from the grid

I want to live sustainably and lower my carbon footprint

I dont mind investing upfront to make any of the above come true

How To Wire Solar Panels In A Solar System

When you are wiring solar panels, you have three choices on how you wire the system

  • Series solar panels plus to minus, plus to minus
  • Parallel solar panels Plus to plus, minus to minus
  • Mixed strings of series panels connected in parallel

When deciding between the three, two important facts to consider are the maximum input voltage of your charge controller and the type of charge controller.

Every charge controller has limits on how much voltage it can accept , anything from 20V on the low end to 160+ V on the high end. You must be sure that the power coming in from your solar panels never exceeds this number.

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Key Decisions You Need To Make While Wiring Your Off Grid Solar System

There are number of choices that you have to make when installing a DIY off grid solar system that affects how you wire the system together. In particular, you will need to decide:

  • The number of panels and voltage of your solar panel array
  • Your overall system voltage, based on battery bank size and your energy needs

S In Installing An Off

DIY 13kW 48V Offgrid Solar System: How to build it from scratch!

Although designing and installing an off-grid system isnt terribly difficult, it has noticeable complexity and involves a more or less fixed sequence of steps.

1. Load Calculation and System Sizing

The first step that comes before installing any of the components is figuring out the specifications and the quantity of the components you will require based on how much energy and continuous power you will be using.

To begin with, you need to list all your electrical appliances, their power consumption, and duration of use, as shown in the following example:

Based on how much energy you will use during sunny and dark hours, you may need to store this entire 3000 Wh in a battery or a part of it. It is safer to assume you will store all of it in the batteries, meaning you need a 3kWh or higher capacity battery bank.

As for the solar panel size, it will depend on the location. While some areas receive up to 5 hours of full sunshine on average, some receive only about 3. You can refer to one of the many sources on the internet for average sunshine hours in Canada.

Lets assume that you are in a region with four hours of average daily sunshine. The solar panel capacity needed will thus be 3000 Wh / 4 h = 750 W.

These basic calculations can provide you with a rough approximation for the size of solar panels and the battery required.

2. Installing the Batteries

Once you have the specs for everything, start by purchasing and installing the batteries first.

600/12 x 1.3 = 65 A

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What Is Your Daily Kwh Usage

Using the load evaluation worksheet you filled out, multiply the appliance wattage by the number of hours it will be in use each day. As an example, if you run a 1,500-watt dishwasher for 30 minutes each day:

1,500 watts x 0.5 hours = 750 watt-hours

Remember to divide by 1000 to convert from watts to kilowatts.

750 Wh / 1000 = 0.75 kWh daily usage

Repeat this step for each appliance you will use, and tally them all up to get your daily kWh usage. Write that number in your notes.

It Is Frequently The Only Viable Option

When you’re seeking to operate a structure in a distant location, such as a cottage deep in the woods, there’s a good possibility you won’t be able to connect to a power grid.

When you phone the utility firm to seek a connection, you will very certainly be told that you are beyond their service area.

Alternatively, they may lay the lines that link you to the grid for you – nevertheless only at an excessive cost.

As a result, you’ll have to create your electricity.

A backup generator could be used, but the fuel is costly, and renewable power sources like hydropower and wind aren’t easily available in most places.

As a result, solar power is the only viable off-grid power generation option.

Solar electricity, on the other hand, has several drawbacks.

Even though solar energy offers several important advantages, the vast majority of individuals choose to stay connected to the grid even though they install solar on their roofs for a variety of reasons.

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Victron Color Control Gx & Vrm Portal

The Color Control GX is the communication center of you entire off-grid power system. It controls all products connected to it, gives live info at a glance, and even creates a Remote Management Portal so you can access you system from anywhere in the world.

Before you fire up your system for the first time, youll want to make sure everything is connected to this display.

Youve already connected the REC BMS via the VE.Can Bus, but in order for it to talk directly to everything youve got a few more cables to run.

To connect the Quattro Inverter, use a VE.Bus or Ethernet cable. And for the MPPT Solar Charge Controllers, use VE.Direct cables. The display also needs power, so connect its positive and negative wires to the positive and negative of the system.

You may need to put a Terminator Plug into your second VE.Can slot , and if you want to run the VRM portal full time, a USB WiFi adapter will allow you to connect the display to your network. Hardwiring ethernet is also an option. You can even get a USB GPS adapter if your system is on the move. Pretty cool!

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