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Calpro Solar vs Diablo Solar Services
Contra Costa Solar Contractors Comparison · Updated March 2026
Both are highly experienced veteran contractors with 40+ years in solar, but they serve different needs: Calpro focuses on new photovoltaic installations while Diablo offers comprehensive maintenance and repair services.
| Calpro Solar | Diablo Solar Services | |
|---|---|---|
| Rating | ★ 5.0 | ★ 4.2 |
| Years Licensed | 37 years | 42 years |
| License # | 549715 | 454228 |
| Workers' Comp | ✓ Yes | ✓ Yes |
| Bond Amount | $25,000 | $25,000 |
| Location | Brentwood, CA | Martinez, CA |
| Website | calprosolar.com | diablosolar.com |
Key Differences
What Customers Say
Calpro Solar
Calpro Solar customers consistently emphasize the no-pressure sales consultation and smooth installation process with professional communication throughout the project.
Diablo Solar Services
Diablo Solar Services customers highlight long-term service relationships, thorough technical inspections, and the company's preference for cost-effective repairs over unnecessary replacements.
Key Takeaway: Calpro's feedback centers on the new installation experience from consultation through completion, while Diablo's feedback reflects ongoing service relationships with some customers reporting 10 to 20 years of continued maintenance and support.
Customer Reviews
Calpro Solar
Very great full to George and his family for quick response and taking care of the issue with my Solar. He had installed Solar with backup battery two years ago through Sungrade based out of Walnut Cr...
To all of you out there considering various solar companies, I had the good fortunate to work with CalPro Solar. Prior working with them, I went through several other solar providers. Each one had the...
Super professional and friendly people doing great work. It has been a pleasure working with them.
Diablo Solar Services
Mike and his team are incredible, and I don't say that lightly. From my own personal experience working with both solar and pool service companies, Diablo Solar is an easy one for me to recommend. The...
Diablo saved me from another solar company that tried to pressure me into a more expensive program for repair of my solar panel. Diablo saved me thousands of dollars with expert advice and a staff tha...
Unlike many of their competitors, Diablo were willing to expand and existing solar system, and were able to maximally exploit existing equipment to cut the total cost. They did not try to oversell, co...
Consider Calpro Solar if...
- ✓ You're planning a new photovoltaic or battery backup installation and want a straightforward consultation without aggressive sales tactics that multiple customers specifically contrasted favorably against other solar companies.
- ✓ Communication throughout your project matters significantly to you, as customers consistently note clear explanations from office staff and professional installation teams.
- ✓ You prefer working with a contractor focused specifically on photovoltaic installations rather than splitting attention across multiple solar system types.
- ✓ On-time or early project completion is a priority, as customers report installations finishing on schedule or ahead of projections.
Consider Diablo Solar Services if...
- ✓ You need ongoing maintenance, repairs, or seasonal startup and shutdown services for either photovoltaic or pool solar systems, which represents Diablo's core service strength.
- ✓ Your solar panels require removal and reinstallation for roof replacement, a coordination service Diablo handles regularly according to customer feedback.
- ✓ You value a long-term service relationship with a company customers have trusted for 10 to 20 years for continued system care.
- ✓ You want a contractor who will assess whether repairs can extend your system's life rather than automatically recommending replacement, as multiple customers specifically praised this cost-saving approach.
- ✓ You have a pool solar heating system or are considering one, as Diablo maintains specific expertise in this technology alongside photovoltaic systems.
Questions to Ask Before Hiring
- → Ask Calpro Solar what their post-installation service approach includes and whether they offer ongoing maintenance contracts, since customer feedback focuses primarily on installation rather than long-term servicing.
- → Ask Diablo Solar Services about their current scheduling availability and how they manage communication during busy seasons, as some customers noted challenges in these areas.
- → If you're considering battery backup, ask both companies about their specific experience with battery system installations and what brands they work with regularly.
- → Ask for references from projects completed in the past year that match your specific needs, whether that's a new installation or ongoing system maintenance.
The Bottom Line
Your decision depends entirely on what you need. For a new photovoltaic or battery backup installation with a consultative, no-pressure sales process and strong project communication, Calpro Solar delivers exactly that experience according to consistent customer feedback. For ongoing maintenance, repairs, pool solar systems, or a long-term service relationship with a company customers have trusted for decades, Diablo Solar Services offers the comprehensive service range you need. Both are properly credentialed veteran contractors, so this comes down to service fit. If you need installation only, Calpro's focused approach works well. If you need a full-service solar partner for years to come, Diablo's broader capabilities become essential.
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Frequently Asked Questions
Diablo Solar Services demonstrates clear strength in both areas with customer feedback spanning installation through decades of maintenance relationships. While Calpro Solar handles new installations exceptionally well, their customer feedback centers on the installation experience rather than long-term servicing. If ongoing maintenance matters to you, ask Calpro directly about their service program details to compare what each offers.
Not meaningfully in this case. Both companies operate as veteran contractors with 37 and 42 years respectively, meaning both have navigated multiple technology generations, building code changes, and market shifts. The difference in their service approach matters far more than five additional years when both have decades of operational history.
Based on available information, Calpro Solar specializes in photovoltaic and battery backup systems without specific mention of pool solar heating. Diablo Solar Services explicitly handles pool solar installation, maintenance, seasonal startup and shutdown, and leak repairs with positive customer feedback in this area. For pool solar work, Diablo represents the clear choice.
Calpro Solar customers specifically highlight the absence of sales pressure during consultations. Diablo Solar Services customers praise the company's willingness to recommend repairs over replacements when appropriate, with several noting cost savings from this approach. Both demonstrate integrity in their sales approach, but in different contexts: Calpro during initial sales, Diablo during service assessments.
Looking for the Best?
See our ranked list of top solar contractors in Contra Costa.
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How We Compare Contractors
License Verification
All license data is sourced from official California CSLB records and verified regularly.
Review Analysis
Customer reviews are aggregated from Google and analyzed to identify patterns in service quality.
Detailed Comparison
We analyze credentials, insurance, experience, and feedback to highlight meaningful differences.
Not all licensed contractors are created equal. While a valid license is the baseline requirement in California, contractors can vary significantly in experience, insurance coverage, and customer satisfaction.
- Experience matters: A contractor with 15+ years of experience has likely encountered and solved problems that newer contractors haven't faced yet.
- Workers' compensation protects you: If a contractor without workers' comp insurance has an employee injured on your property, you could be held liable.
- Reviews reveal patterns: Individual reviews can be misleading, but patterns across many reviews often reveal a contractor's true strengths and weaknesses.
- Bond amounts vary: A contractor's bond provides financial protection if they fail to complete work as agreed. Higher bonds offer more protection.
Taking time to compare contractors on these factors can save you from costly mistakes and help ensure your project is completed by a qualified professional.
Data Sources: License information from California CSLB. Ratings and reviews from Google. Last verified March 13, 2026.
This comparison is based on publicly available information. We recommend getting multiple quotes and verifying all credentials directly before hiring.
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