15 Best Solar Companies in Diamond Bar, CA (2025 Reviews)

We analyzed over 1500 solar companies in the nation,
and have selected the top 15 in Diamond Bar based on:

  • Customer review scores
  • Service area for Diamond Bar, CA
  • Company policies and services offered
  • Accreditations and certifications

Average Diamond Bar homeowner saves $2,108/year with solar panels

By EcoWatch Local Advisors

Data Analysis: James Savino

Ranking Methodology: Karsten Neumeister

Updated January 24, 2025

Why you can trust EcoWatch

We work with a panel of solar experts to create unbiased reviews that empower you to make the right choice for your home. No other site has covered renewables as long as us, which means we have more data and insider information than other sites. Our rankings are never affected by revenue or partnerships.

Best Solar Companies in Diamond Bar

When choosing between the best solar companies, Diamond Bar homeowners have more options to choose from than ever before, which can be too much to get a handle on, but we’re here to make switching to solar energy that much easier. Because Diamond Bar has a very high capacity for solar energy generation, switching to solar is financially rewarding for many homeowners.


If you’re thinking about going solar, the first step you should take is to find the best solar companies in Diamond Bar and compare quotes. The great news is we took the time and put together a list of the best solar companies so you don’t have to.Continue reading to see our picks for the top solar companies in the city, or get connected with a certified solar company in your area right away by clicking the button below.

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Best Regional Coverage

Momentum Solar

★★★★★
4.5
  • Great warranty coverage
  • Representatives are experts on local policies
  • Concierge service ensures steady communication
  • Slightly limited service offerings

Best for Leasing

Sunrun

★★★★★
4.0
  • Expansive service area
  • Many financing options
  • Some reported issues with customer service
  • Some reported issues with door-to-door sales

EcoWatch Rankings for Solar Companies in Diamond Bar

Best Local Installer
ecowatch badge icon

EcoWatch Rating

4.4/5

SunPower by Sea Bright Solar

  • Pros icon Clear Pricing Policy
  • Pros icon Reliable Customer Support
  • Pros icon Free Quotes
  • Con icon Limited information available on website

Services Offered

  • Service icon Financing Assistance
  • Service icon Battery Storage
  • Service icon Panel Installation
  • Service icon Consultation

Website: https://seabrightsolar.com/
Address: 1785 Industrial Park Ave Building A, Redlands, CA 92374
Phone: 9093475451
Outstanding Local Installer
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EcoWatch Rating

3.0/5

Precis Solar

  • Con icon Limited information available on website

Services Offered

  • Service icon Financing Assistance
  • Service icon Permit Assistance
  • Service icon Battery Storage
  • Service icon Consultation
  • Service icon Panel Installation

Website: http://www.precissolar.com/
Address: 36625 Kevin Rd STE 147, Wildomar, CA 92595
Phone: 9514762975
Outstanding Local Installer
ecowatch badge icon

EcoWatch Rating

3.0/5

SunPower by Sun Solar-OC

  • Pros icon Reliable Customer Support
  • Con icon Limited information available on website

Services Offered

  • Service icon Consultation
  • Service icon Battery Storage
  • Service icon Panel Installation
  • Service icon Cleaning and Maintenance

Website: https://sunpowerbysunsolaroc.com/
Address: 4085 E La Palma Ave Suite B, Anaheim Hills, CA 92807
Phone: 9497349695
Outstanding Local Installer
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EcoWatch Rating

3.0/5

SunPower by True Power Solar

  • Pros icon Reliable Customer Support
  • Con icon Limited information available on website

Services Offered

  • Service icon Cleaning and Maintenance
  • Service icon Panel Installation

Website: http://www.truepowersolar.com/
Address: 201 Clark Ave, Pomona, CA 91767
Phone: 7146768888
Outstanding Local Installer
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EcoWatch Rating

5.0/5

SunGuide Solar Inc

  • Pros icon Free Quotes
  • Pros icon Informative Resources
  • Con icon Limited information available on website

Services Offered

  • Service icon Panel Installation
  • Service icon Consultation

Website: http://www.mysunguide.com/
Address: 1057 E Imperial Hwy #307, Placentia, CA 92870
Phone: 6269414181
Outstanding Local Installer
ecowatch badge icon

EcoWatch Rating

5.0/5

SolarRepair

  • Pros icon Informative Resources
  • Pros icon Clear Pricing Policy
  • Pros icon Reliable Customer Support
  • Pros icon Free Quotes
  • Pros icon Prompt Service Delivery
  • Con icon Limited information available on website

Services Offered

  • Service icon Panel Installation
  • Service icon Cleaning and Maintenance
  • Service icon Skilled Repairs
  • Service icon Battery Storage
  • Service icon Financing Assistance
  • Service icon Solar Panel Upgrades

Website: https://www.mysolarrepair.com/
Address: 2834 Hamner Ave #464, Norco, CA 92860
Phone: 8337574255
Outstanding Local Installer
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EcoWatch Rating

5.0/5

Altadena Energy & Solar

  • Pros icon Reliable Customer Support
  • Pros icon Informative Resources
  • Pros icon Clear Pricing Policy
  • Pros icon Free Quotes
  • Con icon Limited information available on website

Services Offered

  • Service icon Panel Installation
  • Service icon Battery Storage
  • Service icon Permit Assistance

Website: http://www.altadenasolar.com/
Address: 1585 N Lake Ave, Pasadena, CA 91104
Phone: 8182014206
Outstanding Local Installer
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EcoWatch Rating

5.0/5

SunSolar U.S.

  • Pros icon Clear Pricing Policy
  • Pros icon Informative Resources
  • Pros icon Free Quotes
  • Pros icon Reliable Customer Support
  • Pros icon Prompt Service Delivery
  • Con icon Limited information available on website

Services Offered

  • Service icon Battery Storage
  • Service icon Panel Installation
  • Service icon Financing Assistance
  • Service icon Consultation
  • Service icon Solar Carports
  • Service icon Permit Assistance

Website: http://sunsolarus.com/
Address: 16755 Von Karman Ave Suite 200, Irvine, CA 92606
Phone: 9492420088
Outstanding Local Installer
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EcoWatch Rating

5.0/5

REPOWER OC

  • Pros icon Prompt Service Delivery
  • Pros icon Clear Pricing Policy
  • Pros icon Free Quotes
  • Pros icon Informative Resources
  • Pros icon Reliable Customer Support
  • Con icon Limited information available on website

Services Offered

  • Service icon Financing Assistance
  • Service icon Panel Installation

Website: http://www.repoweroc.com/
Address: 2942 Century Pl Suite 760, Costa Mesa, CA 92626
Phone: 7144647721
Outstanding Local Installer
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EcoWatch Rating

5.0/5

SYNRG Solar - Home Energy Solutions

  • Pros icon Reliable Customer Support
  • Pros icon Clear Pricing Policy
  • Con icon Limited information available on website

Services Offered

  • Service icon Consultation
  • Service icon Panel Installation

Website: http://synrgsolar.com/
Address: 333 Chaumont Cir, Foothill Ranch, CA 92610
Phone: 9497421680
Outstanding Local Installer
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EcoWatch Rating

5.0/5

Renew Earth Solar

  • Con icon Limited information available on website

Services Offered

  • Service icon Consultation
  • Service icon Panel Installation
  • Service icon Battery Storage
  • Service icon Grid-Tied Solar System

Website: http://renewearth.com/
Address: 895 Dove St #300, Newport Beach, CA 92660
Phone: 8557270629
Outstanding Local Installer
ecowatch badge icon

EcoWatch Rating

5.0/5

Solar Source

  • Pros icon Family-Operated Business
  • Pros icon Reliable Customer Support
  • Pros icon Informative Resources
  • Pros icon Clear Pricing Policy
  • Pros icon Free Quotes
  • Con icon Limited information available on website

Services Offered

  • Service icon Panel Installation
  • Service icon Permit Assistance
  • Service icon Financing Assistance

Website: https://solarsourceinc.com/
Address: 2954 E 14th St, Long Beach, CA 90804
Phone: 5628525626
Outstanding Local Installer
ecowatch badge icon

EcoWatch Rating

5.0/5

Green Integrations and Management Inc.

  • Pros icon Clear Pricing Policy
  • Con icon Limited information available on website

Services Offered

  • Service icon Battery Storage
  • Service icon Panel Installation

Website: http://www.gimenergy.com/
Address: 3108 Glendale Blvd, Los Angeles, CA 90039
Phone: 8189005471
Outstanding Local Installer
ecowatch badge icon

EcoWatch Rating

5.0/5

Powerfull Solar, Inc

  • Pros icon Informative Resources
  • Pros icon Prompt Service Delivery
  • Pros icon Reliable Customer Support
  • Pros icon Free Quotes
  • Con icon Limited information available on website

Services Offered

  • Service icon Cleaning and Maintenance
  • Service icon Solar Carports
  • Service icon Consultation
  • Service icon Panel Installation
  • Service icon Permit Assistance
  • Service icon Financing Assistance

Website: https://www.powerfullsolarinc.com/
Address: 5316 Venice Blvd., Los Angeles, CA 90019
Phone: 3108047617
Outstanding Local Installer
ecowatch badge icon

EcoWatch Rating

5.0/5

ProSolar California

  • Pros icon Free Quotes
  • Pros icon Informative Resources
  • Pros icon Reliable Customer Support
  • Con icon Limited information available on website

Services Offered

  • Service icon Financing Assistance
  • Service icon Tesla Powerwall
  • Service icon Battery Storage
  • Service icon Panel Installation

Website: http://www.prosolarcalifornia.com/
Address: 5701 Buckingham Pkwy, Culver City, CA 90230
Phone: 3238971538

Methodology: How We Ranked the Best Solar Companies in Diamond Bar

EcoWatch's solar experts analyzed each solar company in Diamond Bar based on criteria such as its reputation in the industry, customer reviews, services, warranty coverage and financing. Using this solar methodology, we used the data we collected to rate and rank each company and narrow down our picks for the best solar companies in Diamond Bar


Below are some the criteria we examined specifically for California solar companies

  • Brand reputation and certifications (20%): We take each company's Better Business Bureau (BBB) score into consideration, as well as how long the installer has been in business (at least 5 years is required, 10 preferred) and what type of solar certifications it holds.
  • Customer reviews (20%): Trust is a top priority at EcoWatch, so we take customer experience under close consideration. We scour different review sites and customer testimonials when ranking our top solar companies, checking sites such as Trustpilot and Google Reviews. We also consider any potential complaints or lawsuits filed against these companies and award or remove points accordingly.
  • Warranty (20%): A company earns a perfect score in this category if it offers 25-year warranties that cover performance, product and workmanship. The industry standard that we measure companies against is 25-year product and performance warranties, along with a 10-year workmanship warranty. We also look closely into the track record of the post-installation support each company provides in terms of honoring its contracts
  • Solar services (10%): All of the companies we review install solar panels, but we award companies higher points if they offer additional services for customers, like battery installation, energy-efficiency audits, and EV chargers.
  • Pricing and financing (10%): It's hard to get exact quotes for solar projects, but we use marketplace research to determine how each company prices its equipment and installation services. Additionally, companies that offer more help for panel financing — like in-house loans, leases, or PPAs — score higher than those that don't.
  • Availability (10%): The bigger the service area, the higher the company will score.
  • Transparency and accessibility (5%): Solar installers that offer free consultations and easy contact methods score higher in this category.
  • Environmental, social and corporate governance factors (5%): A company earns a perfect score in this category if it offers public data disclosure, addresses end-of-life (EOL) products or processes, and demonstrates a commitment to uplifting the communities that it serves.

The Cost and Benefits of Solar in Diamond Bar

The cost of installing a solar panel system has gone down significantly in the past several years, but it’s still a significant investment for most homeowners.The cost of solar and the savings it generates vary depending on some important factors such as:

  • The kind of solar panels you’re thinking of getting: Higher-efficiency panels have higher prices, so that will shape your budget for your solar project.
  • Incentives: Along with the federal Solar Investment Tax Credit (ITC), which lets you deduct 0 of your overall installation cost, your state or local government may offer additional tax exemptions, credits or rebates that will help you save even more. Excluding incentives, you can save an average of $25,000 over the first 20 years with your solar system, too.
  • The amount of sunlight your roof gets: Because of Diamond Bar’s very high amount of average daily sunlight, you should be able to save a lot on your electricity bills.
  • Energy consumption: Installing solar panels may be too steep of an investment for homes that don’t use too much energy each month.

Solar is a worthwhile investment for most homeowners. You can produce your own electricity instead of paying for it from a utility company and make use of solar tax credits and rebates, all while helping protect the planet.

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Solar Incentives in Diamond Bar

Although installing solar panels is typically a big investment, it can save you a substantial amount of money over time because of lower utility bills and government incentives.Regardless of what state you live in, you can take advantage of the federal Solar Investment Tax Credit (ITC), which will allow you to claim 0 of how much you paid for your solar installation when you file taxes, reducing the amount of taxes you owe that year. In addition, there may be some local incentives you can benefit from too. In our article on solar incentives, you can read about the incentives you qualify for near you.

Environmental Impact of Switching to Solar in Diamond Bar

One of the best reasons to use solar power is to decrease your dependence on nonrenewable energy sources like burning fossil fuels, which are damaging for the environment.But – how much exactly can you help the environment by making the switch to solar? A key thing to keep in mind is your overall carbon footprint. For example, if you have a long commute, your footprint may be greater, so adopting solar power for your home can help offset that.In fact, if you install solar panels, you could reduce your carbon dioxide emissions by about 50 pounds each year. If you care about the environment, you’ll likely find that there are many benefits of adopting solar power other than just saving money on bills. You can also help protect the environment, which some would argue is more valuable.

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Best Regional Coverage

Momentum Solar

★★★★★
4.5
  • Great warranty coverage
  • Representatives are experts on local policies
  • Concierge service ensures steady communication
  • Slightly limited service offerings

Best for Leasing

Sunrun

★★★★★
4.0
  • Expansive service area
  • Many financing options
  • Some reported issues with customer service
  • Some reported issues with door-to-door sales

EcoWatch's Diamond Bar, CA Solar Company Rankings FAQs

What is the best solar company in Diamond Bar?

In Diamond Bar, SunPower by Sea Bright Solar is the top local solar company. Our team of experts rates it 4.40 stars, so it's a solid choice if you're planning to add solar panels to your roof.

What is the negative environmental impact of solar panels?

Manufacturing solar panels requires chemicals and produces toxic waste that can be bad for the environment, which is the main downside of solar panels.

How long does it take for solar to pay for itself?

Solar panels usually pay for themselves in about 9.2 years, but your solar payback period will vary based on your utility costs. The higher your typical energy bill, the faster your solar panel system will pay for itself.

When should I install solar panels?

You can install solar panels whenever it's convenient for you, but consider doing so in the winter when the demand is less. With fewer homeowners going solar, you could potentially see faster installation times and more savings.

Our goal is to reach as many people as we can with sensible solutions like solar energy. Our team of full-time local researchers collects solar price and installation data for every city in America then compiles it to create these digestible city guides. If you want to read our solar expert’s opinion on the top solar companies featured here, follow this link.

Company research was conducted by Melissa Smith and Karsten Neumeister. Local data analysis was conducted by James Savino. See something we missed or could do better? Email the editor.