How to Add Solar Panels to an Existing Solar Energy System

Updated: September 3, 2025

When the sun shines bright in Phoenix, AZ, your energy needs may increase. Expanding your solar power system can be a great choice. Adding solar panels to your existing system can give you the extra power you need. This is true whether you are charging an electric vehicle or upgrading your home with energy-heavy appliances. This guide will help you improve your solar system. It covers how to assess your needs and understand the costs.

At Solar Topps, we serve the entire state of Arizona. While we are located in Downtown Phoenix, we specialize in the main areas of Scottsdale, Paradise Valley, Fountain Hills, Peoria, Mesa, Gilbert, Chandler, and more!

If you want to Go Solar with us, please fill out a Residential or Commercial Quote. 

Understanding Your Need for More Solar Power  and Your Existing System

As life evolves, so do your energy needs. Perhaps a new electric vehicle graces your driveway, or maybe you’re transitioning to a more sustainable lifestyle by electrifying your home. These changes often mean your original solar system, which was once sufficient, now falls short. Before you think about adding more panels, let’s look at why homeowners in Phoenix choose a solar upgrade. 

When to Consider Expanding Your Solar System 

The decision to add more panels isn’t one to take lightly. Key indicators that it’s time for an upgrade include: 

• Electric Vehicle (EV) Ownership: Charging your EV could significantly increase your household’s electricity demand. 
• Home Electrification: Switching to electric appliances for cooking, heating, and daily activities. 
• Increased Energy Consumption: Lifestyle changes or additions to your home, like a new pool, can bump up your energy usage. 

How Many More Panels Do I Need for my Existing System? 

The number of panels you’ll need to add depends on several factors, including your increased energy consumption and the capabilities of your current system. On average, adding five to ten panels is sufficient for most homeowners. However, it’s crucial to consult with a solar expert to tailor the expansion to your specific needs. 

The Cost of Solar Expansion in Arizona 

Adding solar panels isn’t just about meeting your energy needs; it’s also an investment. The cost per additional watt of solar power averages around $3.00, but prices can vary. Once again, your solar installer can guide you as to what the current prices would be to modify your system. 

Understanding Your Energy Usage Patterns for your Arizona Home

To estimate your solar energy needs in Arizona, begin by reviewing your energy consumption history. Arizona residents often experience higher energy usage during summer months due to cooling demands, but patterns may vary based on personal habits and household size. Check your utility bills for the past 12 months to calculate your average monthly and annual energy consumption in kilowatt-hours (kWh). This will provide a solid baseline for determining how much additional solar energy capacity you may require.

Considering Arizona’s Solar Potential

Arizona is known for its abundant sunshine, boasting some of the highest solar energy potential in the United States. When estimating your solar energy needs, take into account the daily average sunlight hours specific to your location. Areas in Arizona typically receive between 5 to 7 peak sunlight hours per day. This data, combined with your energy usage patterns, helps in calculating the amount of energy your solar panels can generate and how many additional panels may be necessary to meet your requirements.

What to Consider Before Upgrading Solar Panels 

Upgrading your solar panel system isn’t as simple as just adding more panels. Several considerations must be considered: 

1. Roof Space and Condition: Ensure your roof has enough space and is in good condition to support additional panels. 
2. System Ownership: If you’re leasing your panels, you may have limitations on system modifications that would need to be discussed with the leasing company beforehand. 
3. Original System Compatibility: Adding panels that are compatible with your existing system ensures efficiency and avoids potential technical issues. However, depending on the type of inverters you are using, you may be limited in whether your system can grow. 

Why Work with Your Original Installer? 

Your original solar installer has a deep understanding of your current setup and can provide valuable insights into the best way to upgrade your solar panel system. They can ensure that any additional panels are fully integrated and optimized for performance, avoiding the pitfalls of a mismatched system, as well as any existing installation warranties. 

Seamless Transition from Your Original Installer

At Solar Topps, we specialize in helping homeowners transition smoothly from their original solar installer. Our team evaluates your current system to understand its design, capacity, and compatibility with future upgrades. By addressing any concerns and ensuring proper integration, we make the transition process simple and hassle-free, allowing you to continue enjoying uninterrupted solar energy benefits.

Long-Term Maintenance for Your Solar Energy System

Maintaining the efficiency and performance of your solar energy system is key to maximizing its lifespan. Solar Topps offers comprehensive maintenance services, including routine inspections, cleaning, and system diagnostics. Our professional team ensures that your system operates at peak efficiency for years to come, safeguarding your investment and your energy independence.

Is Solar Panel Expansion Right for You? 

Before diving into solar expansion, carefully consider your energy goals and requirements. Utilizing solar calculators and consulting with professionals can provide clarity on whether adding panels is the best move. For many, the benefits of expanded solar capacity outweigh the costs, offering long-term savings and increased energy independence. For more information, be sure to reach out to us at Solar Topps to see what we can do to help with your future energy needs.