When you think of going off-grid, what comes to your mind? Many imagine living in a cabin in the forest with no conventional utilities such as electricity, gas, and water.
If you have considered venturing into an off-grid life, you are probably considering installing solar panels to generate electricity.
But how many solar panels do you require to power a house away from the national grid? Solar panels generate about 1.8 kWh per panel daily. You will need 17 solar panels to meet your household’s average need of 29.33 kWh of electricity per day.
I wish I could give you a one-word answer, but the subject is complex because it depends on everyone’s energy needs.
This blog post will demonstrate how to determine your solar energy requirement. Depending on your circumstances, I will also estimate how many solar panels you need for off-grid living. Let’s go off-grid.
You might also be interested in exploring 7 Essential solar panel cleaning equipment and the best ways to use them!
Going Off-Grid: What Does It Mean?
Before you buy into the idea that living off-grid is death by the cup, hold your breath. Many are leaving the noise and hustles in the cities for a quiet, serene life off-grid.
The term off the grid refers to people who decide to run their homes without relying on the national electrical grid.
While some people consider going off-grid as living rough, it does not have to be unbearable. I know some people who enjoy this type of living and will not exchange it for any other lifestyle.
Living off-grid means you create and utilize your utilities like water, electricity, and gas. Solar panels are a source of electricity for heating and running house appliances.
Off-grid homes are common in remote areas away from popular government utilities like municipal sewerage systems, water, and electricity.
However, even people living in places with the national grid can also decide to go off-grid and generate their electricity from solar panels.
Environmentally conscious individuals who want to reduce their carbon footprint, reduce utility costs, and save the planet from global warming are also adopting off-grid living.
In short, going off-grid means that you can generate your own electricity, utilize your own drinkable water, manage your sewer system, and grow your food.
Equipment Needed For An Off-Grid Solar System
You will require 4 major components to build an off-grid solar system
1- Solar Panels
You will decide on the type of solar panels you want to install. Depending on your budget and space, you can choose between 100, 200, 300, 350, or 400-watt solar panels.
The panels have numerous connected photovoltaic cells that absorb sunlight, converting it into electricity.
2- Charge Controller
This instrument monitors and modifies the flow of energy from solar panels to the storage battery. It protects the battery from overcharging, thus reducing safety hazards.
3- Battery
It helps store excess energy from the panels. You can use this energy to run your appliances at night when the sun is out.
They are valuable for the off-the-grid solar system because you have no national grid to supply you with power on cloudy days or at night.
If you are interested in batteries for solar power storage, I wrote a whole article that I encourage you to check out.
4- Inverter
Electricity from solar panels and batteries is direct current (DC), but your appliance runs on alternating current (AC). The inverter will convert DC to AC to power your house.
You might also enjoy reading: 7 Best tips for choosing batteries for solar Panels.
Can Solar Panels Help Me Go Off-Grid?
If you are asking about your energy need, solar panels can produce adequate energy for your off-grid living.
Solar system in a house means you are creating 100% clean energy. However, building a solar system for your house is just one of the puzzles in supplying energy off-grid.
Since you are not connected to the grid, how will you get energy when the sun is not shining? At night, on cloudy days, and in winter, you may greatly suffer if you don’t have a stable power source.
That is where good solar battery storage systems come in. You may want to invest in solar batteries or stations to store the solar energy from the panels.
So, before you pack your bags to live off-grid, ensure you have installed solar panels on your property and have a power storage system.
You can also invest in generators to provide power when the sun fails to shine for longer. Knowing that your power sources are sorted will give you peace of mind.
The size of backup power each off-grid house needs depends on its energy consumption (the type and number of appliances) and the amount of electricity from the solar panels.
Now, let’s get to the business of numbers.
How Many Solar Panels Do I Require To Power An Off-Grid House?
Your need for solar panels when going off-grid depends on many factors. Some of these factors include:
- Your home electricity usage.
- The available roof spaces.
- The amount and intensity of sunlight.
- The type of solar panels.
Generally, you may need up to 7000 watts to be self-sufficient in running an off-grid house. But your energy production depends on your solar panels’ performance and energy requirement.
Solar panels’ performance depends on the size, with larger panels generating more power. For instance, a 100-watt panel measures 47x 21.3 x 1.4 inches produces less power than a 200-watt panel that measures 64 x 26 x 1.4 inches.
A 400-watt solar panel has more photovoltaic cells to absorb more sunlight for solar energy.
Now, if the average energy requirement for an off-grid house is 7kW, how many solar panels can meet this need?
If you install 200-watt solar panels, you will need 35 of them (7000w/200w). However, if you install 350-watt solar panels, you will need 20 panels.
But how much space will 35 solar panels take? The average square feet for the roof of an off-grid house in the United States is approximately 1700. But one 200-watt solar panel is 16 square feet, meaning the 35 panels will occupy 560 square feet (35 x 16 sq. ft). You can see that installing 35 solar panels still leaves you enough room to add more panels to your system.
The Formula And Criteria For Calculating The Number Of Solar Panels You Need
Here is an easy formula for knowing how many solar panels you need in your home.
If you wonder how to know your monthly electric usage check out your recent power bill. It is often shown on the bill as kWh, with the cost at the bottom of the document in dollars.
The next step is knowing how much sunlight your region will likely receive to determine how many solar panels to run an off-grid house. We are interested in peak hours, not the whole day.
If you live in states with high peak sunlight, like California, Texas, and Florida, you may need a big solar system for a house. You also need to ensure that the roof of your off-grid house has the right angle, faces the right direction, and is not affected by shading.
The National Renewable Energy Laboratory provides each state’s sunlight peak hours. You can check their website for more information.
Calculating The Size Of Your Solar System Needed For Off-Grid Living
Now that you know the number of peak sunlight hours, you can find the number of panels needed.
- Monthly Peak Sun Hours:
- Determine your monthly figure by multiplying the daily peak sunlight figure by 30.
- Next, take your monthly electricity usage, in our case, 1000kWh, and divide it by the monthly peak hours to get your solar system size in (kW).
- The Number Of Solar Panels I Need To Go Off-Grid:
- Convert the units of your solar system from kilo-watts to watts by multiplying the figure by 1000.
- So, if the above figure was 7.0 kW, you will get (6.1 x 1000) 7,000 watts.
- If we assume that you want to invest in 200-watt solar panels, you can calculate the number of panels in your solar system for your house by dividing 7,000 by 200 watts to get 35 panels.
But what about your battery backup?
How Many Days Should My Solar Battery Backup Last?
The number of power bank batteries you need to back up your system depends on several factors, such as the local climate, your energy usage, and other backup plans you may have. A backup battery system will help you at night or when you have little sunshine. They often provide between 3 and 5 days, although it could be longer or shorter.
If you want more days, add more batteries and hope the sun shines longer to help you store more power. Living off-grid requires a battery system and a backup generator, just in case winter comes early.
What to read next:
- Can You Really Put Solar Panels on a Mobile Home?
- Can You Put Solar Panels on a Metal Roof?
- How Many Solar Panels Do You Actually Need to Power a House?
Final Thoughts
How many solar panels are enough to supply my off-grid house energy needs? The answer depends on the sunlight your house will receive, your home power usage, and your solar power storage size.
And because the calculation in this article is based on the worst possible scenario, it protects your home from running out of power even when the sun shines for a few hours. As you settle in on your new lifestyle, you will find unique ways to reduce energy consumption.