Powering Guest Houses and ADUs with Solar in Arizona: What Homeowners Need to Know

Are you considering solar energy for your home in Phoenix? Now is the perfect time to harness the power of the sun and take advantage of significant savings through federal and state tax credits. Our team at Phoenix Valley Solar can help you navigate these incentives and maximize your savings. You can also use our Arizona Solar Calculator to get an estimate of your potential benefits.

As housing costs rise and multigenerational living becomes more common, many Arizona homeowners are adding accessory dwelling units (ADUs) — also known as casitas, guest houses, or backyard suites — to their properties.

Whether you’re building a space for family, generating rental income, or creating a home office, you’ve likely asked:

“Can I power my ADU with solar?”

The answer is yes — and in sunny Arizona, it’s often the smartest way to do it.

Here’s what you need to know about solar panel installation for guest houses, ADUs, and backyard structures in Phoenix and beyond.

1. Why Power an ADU with Solar?

Arizona’s hot climate means even a small detached unit can draw a lot of power — especially in summer.

Common energy needs include:

• A/C (mini-split or wall unit)

• Water heater

• Lights and appliances

• Internet and smart home devices

• Laundry or kitchenette setups

• EV chargers or garage tools if attached to a carport

Rather than run new underground wiring from your main home or pay for higher usage on your existing utility plan, solar offers a clean, cost-effective solution — and may even qualify for incentives.

2. System Design: 3 Ways to Solar-Power Your ADU

Depending on your layout and goals, we can design your system in one of three ways:

1. Integrated Solar System

• ADU shares power with the main home

• Solar system is designed to offset total household usage

• Works well when ADU is not metered separately

2. Standalone Solar System

• Independent array mounted on the ADU roof or nearby ground

• Option to tie to grid or run fully off-grid with battery storage

• Ideal for remote guest houses or detached buildings far from the main home

3. Hybrid System with Battery

• ADU runs independently via solar plus battery

• Offers nighttime power and backup

• Great for rental units or spaces where grid access is limited

We help homeowners choose the best configuration based on utility provider (APS or SRP), property layout, and whether the ADU is for personal or rental use.

3. Can You Install Solar on an ADU Roof?

Absolutely — even small roofs can support high-efficiency panels, especially with:

• Modern 400+ watt panels

• Strategic tilting for flat-roof casitas

• Optimizers or microinverters for partial shading

If the roof is too small, we can install a ground-mounted system, a solar carport, or expand your main home’s system to accommodate the ADU load.

4. Does the Solar System Qualify for Incentives?

Yes — as long as:

• The ADU is on your residential property

• The solar system offsets your utility usage

• You own the system (not leased)

You’re eligible for:

• The 30% Federal Solar Tax Credit (ITC)

• The $1,000 Arizona Solar Tax Credit

If your ADU is used as a short-term or long-term rental, you may also qualify for commercial solar depreciation benefits under Section 179.

We work with local tax advisors to help you maximize your available incentives.

5. Solar for Rental ADUs: Boost ROI and Property Value

Guest houses and backyard rentals are a great income stream — but they also come with:

• Increased energy use

• Complicated billing

• Risk of tenants overusing A/C or utilities

Solar allows you to:

• Keep rental income high while keeping costs low

• Market your property as sustainable or green

• Future-proof against APS and SRP rate hikes

• Appeal to eco-conscious renters or Airbnb guests

Bonus: Homes with solar and an ADU often appraise higher and sell faster in competitive Arizona neighborhoods.

6. Battery Backup for ADUs: Extra Comfort and Security

A solar battery can keep your guest house or casita powered:

• During APS/SRP outages

• At night when solar panels aren’t producing

• If used as a detached office, studio, or therapy space that requires uninterrupted energy

We design compact, efficient systems that use Tesla Powerwall or Enphase IQ batteries to ensure round-the-clock reliability.

Why Phoenix Valley Solar?

We specialize in custom solar system design for:

• Guest houses and detached suites

• Backyard rentals and ADUs

• Home offices and creative studios

• Multi-structure residential properties across the Valley

Our team handles:

• Utility approval (APS/SRP)

• Design and permitting

• HOA and zoning support (if needed)

• Performance monitoring and warranty support

We’re known as the best solar company in Phoenix for homeowners looking to power more than just their main roof.

Ready to Power Your Guest House with Solar?

Contact Phoenix Valley Solar today for a free site evaluation. We’ll help you design the perfect solar solution for your ADU, casita, or rental space — and show you how to maximize savings, comfort, and control.

Are you considering solar energy for your home in Phoenix? Now is the perfect time to harness the power of the sun and take advantage of significant savings through federal and state tax credits. Our team at Phoenix Valley Solar can help you navigate these incentives and maximize your savings. You can also use our Arizona Solar Calculator to get an estimate of your potential benefits.