The number of solar panels needed to go off-grid depends on your energy use, daily sunlight hours, your home's efficiency, and your system’s generation and storage capacity. But in Arizona, going off-grid takes more than just solar panels and efficient appliances—it requires a fully integrated approach to energy planning.
Since you won’t have backup grid power, you need a complete, self-sufficient energy system that can power your home day and night, rain or shine. That means pairing your solar system with a battery storage system, a backup generator – and often, it also means designing your home with energy efficiency in mind.
In this guide, we’ll walk you through what it takes to go off-grid in Arizona, including the benefits of going off the grid, key components of an off-grid solar system, Arizona laws and regulations to navigate, and how to calculate the number of solar panels you’ll need.
Most solar-powered homes in Arizona stay connected to the electricity grid. This setup – commonly referred to as a grid-tied system – lets homeowners pull electricity from the grid when the sun isn’t shining and send excess electricity back during the day in exchange for bill credits. In some cases, grid-tied systems also incorporate a battery to store excess energy to use at night, during expensive on-peak hours, or as energy backup during a blackout.
Off-grid solar systems, on the other hand, operate completely independently from the utility grid. That means there’s no backup power available if solar production dips. To make sure power is always on hand, off-grid homes must include a battery and often a generator, in addition to solar panels.
When solar panels aren’t producing enough electricity – like at night or during cloudy days – the home can pull stored energy from the solar battery to keep everything running. A generator is typically recommended as a safety net in the event of prolonged cloud cover that might slow battery recharge times.
Learn more about how solar power works in our article: How Does Solar Power Work?
Because they’re completely independent from the grid, off-grid solar must meet all your home’s energy needs using on-site equipment. In a sense, you’re turning your home into a personal power plant that must be robust enough to cover 100% of your energy needs, regardless of weather, family size (today and in the future), and home efficiency.
Let’s take a closer look at the essential components of and off-grid system:
Solar panels capture and convert sunlight into direct current (DC) electricity. Off-grid homes usually require more panels than grid-tied systems since they’re the primary source of power.
Batteries are essential in off-grid systems because they store solar energy for your home to use at night or on cloudy days..
The charge controller regulates the flow of electricity from the solar panels to the batteries. It prevents overcharging, which can shorten a battery’s lifespan – therefore helping protect your investment and optimize long-term performance. In most modern solar batteries the charge controller is already built in.
See: Do Solar Panels Still Work When it's Raining or Cloudy?
Solar panels generate DC electricity, but most home appliances run on alternating current (AC). The solar inverter converts DC electricity from your panels and battery into usable AC electricity for your home.
Managing your energy usage is essential in an off-grid home. Energy-efficient appliances, smart load management, and real-time monitoring can help ensure your consumption stays in line with what your system can produce and store.
Even the best solar systems need a backup plan. Generators can kick in when solar and battery reserves run low to keep critical appliances running. These can be a lifesaver during prolonged cloudy weather or surges in energy demand.
In an off-grid home, every bit of energy you produce needs to count. That’s why energy efficiency is essential at every level—from construction materials to appliances. High-quality insulation, energy-efficient windows, and well-sealed doors help prevent air leaks that waste power. Choosing low-consumption appliances, LED lighting, and efficient water pumps ensures your electricity supply is used wisely. Even building materials can play a role—opt for materials that minimize heat gain or loss to reduce the load on climate control systems.
To find out the number of solar panels required to live off-grid, you’ll have to first calculate how much energy your home uses each day. To give you a general idea, the U.S. Energy Information Administration states the average American household electricity consumption is about 900 kWh per month, or roughly 30 kWh per day.
However, there’s no one-size-fits-all answer for this question, and if your house was specially constructed to be off-grid – and is therefore highly efficient – you are likely to consume much less power than the average American home described above.
If your annual energy usage is high, you’ll need more solar panels and probably several batteries. On the other hand, if you’re energy conscious and build your home with efficiency in mind, you’ll require far fewer solar panels and batteries. At the end of the day, it all depends on your electricity usage, how much sunlight is available, solar panel wattage, and your home’s overall efficiency.
In the next section, we share how to calculate the number of solar panels you’ll need. For more detail, read our article: Calculate the Number of Solar Panels You Need
Here’s a step-by-step guide on how to calculate the number of solar panels you need to run a house off the grid:
Go over your electric bills from the last year and find your highest energy usage month. Divide that number by 30 to estimate your maximum daily electricity use in kilowatt-hours (kWh). This gives you a safe benchmark for your home’s total energy consumption and helps size your system accurately.
Next, determine how many peak sunlight hours your location receives each day. Peak sun hours are when solar irradiance reaches an average of 1,000 watts of energy per square meter. In Arizona, this is usually around 7 to 8 hours.
Next look at the orientation of your roof. In the southern hemisphere, south facing roofs provide the greatest sunlight exposure, followed by east and west. North facing roofs are generally discouraged in Arizona but can be worthwhile if they offer ample room for solar panels to make up for the reduction in peak sun exposure.
The power output of solar panels depends on their efficiency and conditions. Even the best panels rarely produce electricity at 100% of their rated capacity due to weather, shading, and other factors.
Let’s say you’re using a 400-watt solar panel and you get 7 peak sunlight hours each day. You can safely estimate production at around 75% efficiency or:
400W x 7 hours x 0.75 = 2,100Wh (2.1 kWh) per panel, per day.
Now, use the below formula to calculate how many panels you need to go off-grid:
Number of Panels = Daily Energy Use / (Panel Wattage x Sunlight Hours x 0.75)
So if your home uses 30 kWh per day and you receive 7 hours of peak sunlight, the formula would be:
30 kWh / (400W x 7 x 0.75) = 14 panels.
Yes, off-grid living is legal in Arizona, but it’s not as simple as just unplugging from the utility. Off-grid systems in Arizona are required to meet a range of building, safety, and environmental regulations to be approved for use. That means homeowners planning to go off-grid need to follow local permitting and inspection processes to make sure their system is safe and compliant.
If you’re considering an off-grid solar system in Arizona, here are the key regulations to be aware of:
Learn More: Is Solar Worth it in Arizona? (2025 Homeowner's Guide)
Going off-grid isn’t just complex, it also often costs more upfront compared to a standard grid-tied solar panel system. For many homeowners, the cost is worth the benefits. For others, the payoff may not be enough.
Here are some of the biggest benefits of going off-grid:
Once you’ve invested in an off-grid system, you’ll never have to pay another utility bill again. Your solar panels, paired with battery storage and a backup generator, will supply all the energy your home needs. That means you’ll no longer have to deal with utility rate hikes, peak demand charges, or surprise fees on your energy bill.
Off-grid systems rely almost entirely on renewable energy, with occasional help from a generator if needed. That means fewer fossil fuels and lower carbon emissions, making your lifestyle more sustainable.
Unlike grid-tied solar systems, which are switched off during outages, off-grid systems continue running. This means your off-grid home will always have power, even when the grid goes down.
Read More: Solar in Power Outages: What You Need to Know
Off-grid solar power gives you the freedom to live in remote or off-the-grid locations where utility access is limited or nonexistent. That means you can build your dream home wherever you like, without thinking about access to power lines.
If you choose to live where there’s no power grid, chances are there’s no water or sewer service either—so you’ll need to plan for those systems yourself.
The cost of an off-grid solar system can vary widely based on factors like the number of panels, battery capacity, need for a generator, home size and efficiency, and local installation costs. Building an off-grid home from scratch is often more cost-effective than retrofitting an existing home, since you can design for efficiency from the start—reducing the size and complexity of your solar and battery system.
One of the main things to be aware of when considering off-grid solar is that you’ll need to install a solar battery or backup generator. Since you won’t have a utility company to fall back on, having a reliable backup power plan is essential to keep your home powered when you need it.
A good-sized solar battery bank can keep your home running for hours, or even days, without sunlight or during extended outages. Generators provide that extra layer of security by automatically kicking in when your battery is depleted. You can choose to opt for just solar batteries or combine both batteries and a generator for full peace of mind. Our team is more than more than happy to talk you through the pros and cons of going off grid.
Read More: Batteries or Generators: Which Backup Solution is Best for Your Home?
Off-grid living isn’t for everyone. For some people there’s no better feeling than the freedom of living independently, while for others, it’s more of a necessity due to living in a remote location with unreliable service.
Living off the grid might be right for you if:
Off-grid living certainly provides freedom, but it also needs careful planning. The most successful off-grid homes are built with energy efficiency in mind from the start. While it’s possible to retrofit an existing home, the process is almost always more costly and complicated.
In the vast majority of cases, a grid-tied solar system with battery backup offers the best return on investment—reducing grid reliance while delivering energy security and savings with a lower upfront cost.
If you’re thinking about going off-grid in Arizona, our first piece of advice is to consult with an experienced solar installer. At Sun Valley Solar Solutions, we specialize in designing and installing custom residential and commercial solar power systems across Phoenix and throughout Arizona.
Whether you’re building a new home or exploring ways to reduce your reliance on the grid, our team can help you understand what it takes to live fully off the grid, and what the right solar system looks like for your specific needs.
We can walk you through:
We’re here to answer your questions and help you explore the pros of cons of off-grid solar. Contact us today to schedule a free, no-obligation consultation to discover whether an off-grid future is right for you.