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Diablo Solar Services vs Northstar Solar
Contra Costa Solar Contractors Comparison · Updated March 2026
Diablo Solar Services brings 42 years of specialized experience versus Northstar Solar's 10 years, with Diablo offering unique pool solar expertise alongside photovoltaic systems.
| Diablo Solar Services | Northstar Solar | |
|---|---|---|
| Rating | ★ 4.2 | ★ 4.7 |
| Years Licensed | 42 years | 10 years |
| License # | 454228 | 1006316 |
| Workers' Comp | ✓ Yes | ✓ Yes |
| Bond Amount | $25,000 | $25,000 |
| Location | Martinez, CA | Danville, CA |
| Website | diablosolar.com | www.gonorthstarsolar.com |
Key Differences
What Customers Say
Diablo Solar Services
Customers consistently praise Diablo's technician expertise, thorough system inspections, and repair-oriented recommendations, with many reporting relationships spanning 10 to 20 years.
Northstar Solar
Customers highlight Northstar's detailed upfront consultations, efficient installation timelines, and responsive communication throughout the permitting and installation process.
Key Takeaway: Diablo's feedback reflects a service and repair focus built on long-term relationships, while Northstar's reviews emphasize streamlined project execution and competitive pricing for new installations.
Customer Reviews
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...
Northstar Solar
I never write reviews, but NorthStar Solar truly earned it. After soliciting multiple bids, Patrick stood out right away - he took the time to do a Zoom call to understand my property and my goals ins...
I had a great experience with my solar and battery installation. The team was very knowledgeable and responsive. The whole installation was very fast from start to finish.
I had a solar system installed by Northstar Solar this past winter, and I am thoroughly impressed with their service. I obtained several bids from different companies, Northstar Solar's bid stood out ...
Consider Diablo Solar Services if...
- ✓ You need pool solar heating installation, repair, or seasonal maintenance, which is Diablo's specialty alongside photovoltaic systems
- ✓ Your solar system is older and may require diagnostic expertise from someone who's seen multiple generations of technology and common failure patterns
- ✓ You prefer a repair-first approach where the contractor evaluates whether fixes make sense before recommending full replacement
- ✓ You value long-term relationships with a contractor who's proven business continuity over four decades
Consider Northstar Solar if...
- ✓ You want a detailed upfront consultation process with energy usage analysis and multiple equipment options presented clearly
- ✓ Your project is a straightforward residential photovoltaic or battery storage installation where efficient execution matters more than decades of legacy system knowledge
- ✓ Competitive pricing is a priority and you're comparing multiple bids for a new installation
- ✓ You appreciate high owner involvement and responsive communication throughout the permitting and installation process
Questions to Ask Before Hiring
- → Ask Diablo about their current service capacity during peak seasons, as reviews mention scheduling challenges during busy periods
- → Ask Northstar for references from projects completed 5+ years ago to understand their long-term warranty support and customer relationships
- → If coordinating solar panel removal for roof replacement, ask both companies about their process, timeline, and how they protect your system during the transition
The Bottom Line
For most residential photovoltaic or battery storage installations, both contractors are qualified, but Diablo Solar's 42 years provides substantially deeper experience for complex situations, older systems, or repair decisions. If you need pool solar services, Diablo is your only choice here. Northstar offers competitive advantages in upfront consultation detail and efficient project execution for straightforward installations. Choose Diablo if your project involves pool solar, system troubleshooting, or you want a contractor who's demonstrated four decades of business continuity. Choose Northstar if you're installing a new photovoltaic system and value detailed energy analysis and streamlined project management at competitive pricing.
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Frequently Asked Questions
It matters most when things don't go as planned. Diablo's four decades mean they've diagnosed unusual roof conditions, handled equipment that's no longer manufactured, and navigated technology transitions from early solar to modern systems. For straightforward new installations on standard roofs, Northstar's 10 years provides solid expertise. The experience gap becomes significant for troubleshooting, repairs, or properties with complications.
No, Northstar's services focus on photovoltaic solar panels and battery storage systems. Diablo Solar specializes in both pool solar heating and photovoltaic systems. If you need pool solar installation, seasonal startup and shutdown, or leak repairs, Diablo is your only option between these two contractors.
Both companies offer this service, but their approaches differ. Diablo's customer feedback specifically mentions coordination assistance and long-term relationships that facilitate these transitions. Northstar handles these projects efficiently as part of their service offerings. Ask each company how many roof coordination projects they complete annually and request references from customers who've done this.
Diablo's reviews emphasize technician knowledge, thorough inspections, and willingness to repair rather than replace, reflecting their service-oriented approach built over decades. Northstar's feedback highlights upfront consultation quality, project efficiency, and competitive pricing, suggesting a streamlined sales-to-installation process. Both receive praise for responsiveness, but Diablo has some notes about customer service scheduling challenges during peak periods.
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 12, 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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