Quite a lot of folks set out for off-grid style living for several reasons like keeping costs low, and being more eco-friendly and self-reliant. A solar panel is the best alternative to power our home using the energy provided by the sun. This guide will help you total how many solar panels it takes to run a house off the grid and also discuss all the factors that affect the panel’s number and size.
How Many Solar Panels to Run a House Off-grid?
For a 10kW off-grid solar system, you will need around 30 solar panels, depending on sunlight exposure. Generating electricity is a major hurdle in off-grid style living. Solar energy shines as the best solution but it requires knowing the number of panels you will need for an off-grid system, followed by certain parameters that will influence the capacity and efficiency of your solar system.
Here are the factors you need to know:
1. Your Energy Consumption
To install a system able to power your home, you need to determine the power your home specifically consumes. This can be achieved by a few clicks, without obstacles.
Simply look through your power bills for every month and try to estimate the sum you spent on electricity for the last several months. This number will be displayed in kWh (kilowatt-hours). By finding out how much power your house consumes, you will have an idea of the solar panel amount you need to cover your demand.
2. Peak Sunlight Hours of the Area
It is considered to be the time when the sun is capable of giving a 1000 watts per square meter average. This varies based on the equipment size because solar panels with a small size often come with reduced efficiency.
An area that receives a lot of sunlight per day would be convenient to gain enough energy from your panels, thus the number of solar panels won’t be that many. Conversely, if your location experiences comparatively fewer hours of sunshine peaks you will have to make for the deficiency by adding more solar panels.
Also, check out the Major Factors Affecting Solar Panel Efficiency
3. Space Available in your Roof
The stability of the roof is also crucial because the panels are heavy, especially if you are considering adding a couple of them. To avoid the possible next issues, it is advised that you contact an expert to check your roof’s condition and see whether it’s strong enough to hold the needed solar panels.
4. Capacity of your Batteries
The off-grid solar systems do not let you switch to the grid of your utility company if solar energy is absent. This could cause you trouble if you are not adequately prepared for this. To avoid such a case you must buy a battery bank that is capable enough to last the night loads as well as on cloudy days.
How to Calculate the Number of Solar Panels you Need to go Off-Grid
Once those considerations are made, you can then estimate the number of solar panels you will need.
Step 1: Evaluate your electricity consumption
To determine how much kW solar panel is required for your home, look at your recent electricity bill and locate kWh. This is most likely to be in the last part of the bill along with the rate/kWh.
Step 2: Count up the number of peak sunlight hours
Below we have provided the solar irradiance data of the best solar states in the U.S. such as California, Texas, Florida, North Carolina, and Arizona.
| State | Average Daily Peak Sunlight Hours (September) |
| California | 5.75 |
| Texas | 5.5 |
| Florida | 4.75 |
| North Carolina | 4.5 |
| Arizona | 5.6 |
This data is for the month of September by NREL.
Step 3: Calculate the needed size of the solar system
As the size of the solar system that you will use will depend on the area’s peak sunlight hours we need to find the average peak sunlight hours per month by multiplying daily hours by 30.
Let’s use the states mentioned above. Secondly, break down the usage of electricity (e.g. 1800 kWh) by the number of hours of sunshine in a month.
You can apply this formula to solve this.
Required Solar System Size = Monthly Electricity Usage/Average Monthly Peak Sunlight Hours.
The results of the calculation for the respective states are in the table below
| State | Average Monthly Peak Sunlight Hours (September) | Required Solar System Size |
| California | 5.75*30 = 172.5 | 10.43 kW |
| Texas | 5.5*30 = 165 | 10.90 kW |
| Florida | 4.75*30 = 142.5 | 12.63 kW |
| North Carolina | 4.5*30 = 135 | 13.34 kW |
| Arizona | 5.6*30 = 168 | 10.71 kW |
Step 4: Work out the number of solar panels needed
The average power output of a residential solar panel is around 350 to 450 Watts.
Next, find out the required number of panels by dividing the total system power output by the power output of an individual panel.
Below we have made a table of the above calculation by using the same states as before and assuming 1800kWh as the monthly bill.
| State | Solar System Size (Watts) | Number of 350W Solar Panel Required (Round Off) |
| California | 10430 | 30 |
| Texas | 10900 | 32 |
| Florida | 12630 | 36 |
| North Carolina | 13340 | 38 |
| Arizona | 10710 | 31 |
Also See: Is Off-Grid Solar Legal in California?
How Much Solar Power for Off-Grid Cabin?
For solar power to be used in a cabin run independently, it may not necessarily have the same energy needs compared to a regular house. It varies from 500W to 1500W depending on the cabin’ size and design, the appliances and devices you use, and location.
Here is a table that shows the approximate solar power needs for different types of off-grid cabins:
| Cabin Type | Size (sq. ft) | Appliances | Solar Power Needed |
| Basic | 400 | Lights, fan, radio, phone charger | 500W |
| Moderate | 800 | Lights, fan, radio, phone charger, TV, fridge, microwave, water pump | 1500W |
| Luxury | 1200 | Lights, fan, radio, phone charger, TV, fridge, microwave, water pump, washer, dryer, dishwasher, oven, AC | 5000W |
Cross-Reference: How To Build a Solar Powered Off Grid Cabin in 6 Easy Steps
Tips to Reduce Consumption While Living Off-Grid
Your first step would be to cut down your energy usage as much as possible as this will not only save you money but make you more self-sufficient.
Here are some techniques to bring your power use down to a minimum.
1. Engage energy efficacy through the use of LED bulbs, gadgets that harness solar energy, and appliances that allow low wattage. Deploy timers, sensors, and dimmers which will provide clever management of lighting with no energy waste.
2. Heat conservation in your home should be your number one priority while using curtains and blinds during warmer periods will help regulate the temperature naturally. Instead of using power hungry air conditioning and heating systems, use fans, fireplaces, and wood stoves to control the temperature without using too much energy.
3. Make your food preparation effective by bringing in pressure cookers, slow cookers, or solar ovens. Be mindful about your meals, cook in bulk, and be creative with the leftovers; there that way you will reduce both food and energy waste.
4. Conserve water by setting up a rainwater collection system, putting in a water purifier system, and also restricting consumption of water to the use of low-flow showerheads and faucets. Reuse the grey water for the usage of irrigation of plants, flushing out the toilets, and washing clothes.
5. Apply minimalism gradually: avoid nonessential purchases, de-clutter your home periodically, and donate or recycle useless items. It will cost less and occupy less space thus utilizing the scarce resources more efficiently, and making your off-grid life better and more sustainable.
To conclude, solar is the best solution to power your home when you’re living off the grid. However, the number of solar panels needed will depend mainly on your location and power usage. This system may be initially expensive but it does pay off in the long run. For more such interesting content, keep reading our blog posts.
Recommended: 10kW Solar System Cost: Off-Grid, On-Grid with Battery Price
