How to Choose a Commercial Solar Installer (Without Getting Burned)
A commercial solar installation is a 25-year commitment to a piece of infrastructure on your building or property. The installer you choose will determine whether that infrastructure performs as promised, whether the project closes on time, and whether you have someone to call when something goes wrong five years from now. Getting the selection process right matters far more than most buyers realize — and most buyers do not get it right.
The Core Problem: Installers Are Salespeople First
Commercial solar installers are in the business of selling and installing solar systems. Their proposals are marketing documents as much as they are technical specifications. The savings projections are optimistic. The equipment descriptions are favorable. The risk disclosures are minimal. This is not dishonesty — it is the nature of a sales process. But it means that evaluating proposals requires a different lens than the installer is providing.
The buyer who evaluates proposals on their own, without independent technical expertise, is at a significant information disadvantage. The installer has done hundreds of these projects. The buyer is doing it once.
What to Look for in a Commercial Solar Installer
- Commercial-specific experience: Residential solar experience does not translate directly to commercial projects. Look for installers with a documented track record of commercial projects at a similar scale to yours — not just a few commercial jobs mixed into a primarily residential portfolio.
- Licensing and insurance: Verify that the installer holds a current C-10 electrical contractor license (in California) and carries adequate general liability and workers' compensation insurance. Request certificates of insurance, not just verbal assurances.
- Interconnection experience with your utility: Interconnection requirements and timelines vary significantly by utility. An installer with extensive SDG&E interconnection experience will navigate the process more efficiently than one who primarily works in other territories.
- Financial stability: A solar installer that goes out of business cannot honor its workmanship warranty. Ask about the company's years in operation, ownership structure, and whether they have bonding in place for larger projects.
- References from comparable projects: Ask for references from commercial customers with projects similar in size and type to yours — not residential customers or much smaller commercial jobs. Call the references and ask specifically about post-installation support and whether the system has performed as projected.
Questions to Ask Every Installer
- Who is doing the electrical work? Many solar installers subcontract the electrical scope. Know who the licensed electrician is and verify their credentials separately.
- What is the interconnection timeline? Utility interconnection is frequently the longest lead-time item on a commercial solar project. Ask for a realistic timeline based on current queue conditions in your utility territory.
- How are production projections calculated? Ask what software is used (PVWatts, PVSyst, Helioscope) and what assumptions are made about shading, soiling, and system degradation. A proposal that does not disclose its modeling methodology is a red flag.
- What happens if production falls short? Some installers offer production guarantees; most do not. Understand what recourse you have if the system underperforms.
- What does the monitoring system show, and who has access? You should have independent access to real-time production data — not just a report the installer sends you.
The Bid Process: Why Three Is the Minimum
Getting three competitive bids is the minimum for any commercial solar project above $100,000. But bids are only comparable if they are based on the same scope of work. Without a defined scope — system size, equipment specifications, interconnection approach, monitoring requirements — each installer will bid a different project, and the lowest number will not necessarily represent the best value.
Defining a scope of work before going to bid is one of the most valuable things an independent solar advisor does. It levels the playing field, makes proposals directly comparable, and prevents the common situation where the lowest bidder wins by omitting scope items that will be added back as change orders.
The Case for Independent Representation
The most effective way to navigate the installer selection process is to have someone on your side who is not selling you a system. An independent solar advisor can define the scope, manage the bid process, evaluate proposals on a technical and commercial basis, and negotiate contract terms — without any financial interest in which installer you choose.
In our experience, clients who engage independent advisory before selecting an installer consistently achieve better pricing, better contract terms, and fewer post-installation surprises than those who go through the process alone.
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The San Diego Solar Buyer's Checklist
Before you sign anything, read this. Our independent advisors put together the exact questions and red flags every property owner should know, completely free.
- Questions to ask every installer before signing
- How to spot inflated system size estimates
- What NEM 3.0 means for your payback period
- Red flags in financing and PPA agreements
- How to run a competitive bid process
- What independent consultants check that installers won't
- Key incentives available in California right now
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