The Best B2B Partner: Top 10 Commercial Solar Companies (2026)

Choosing a commercial solar installer is a multi-million-dollar decision. Unlike residential solar, commercial projects involve complex structural engineering, massive electrical integrations, and specific b2b financing structures. We have audited the top firms in the US market based on **track record, financial stability, and technical expertise.**

1. SunPower Commercial (B2B Solutions)

SunPower remains the gold standard for efficiency. Their Maxeon technology provides the highest energy density per square foot, making them the preferred choice for facilities with limited roof space but high energy demands.

2. Sunrun Commercial (Energy-as-a-Service)

Sunrun leads in PPA (Power Purchase Agreement) structures. For businesses that want to shift to solar with **zero capital expenditure (Capex)**, Sunrun’s financing models are unmatched.

3. Tesla Commercial Energy

Tesla has pivoted strongly toward Megapacks and commercial energy storage. Their ecosystem is the best for businesses requiring **off-grid resilience** or heavy-duty peak shaving capabilities.

4. Greenskies Clean Focus

Ranked #1 for purely commercial focus, Greenskies specializes in wide-scale industrial rollouts across multiple states. They are the go-to for major retail chains and distribution hubs.

5. Borrego Energy

A powerhouse in EPC (Engineering, Procurement, and Construction). Borrego is known for handling the most technically challenging utility-scale and large commercial ground mounts.

What to Look for in a Commercial Partner

Bonding Capacity

A reputable firm must have the bonding capacity to back their work on projects exceeding $1 million. Without this, your business carries significant risk if the contractor fails to perform.

Diligence on O&M (Operations & Maintenance)

Commercial solar is an asset that lasts 30 years. Ensure the company you choose has a dedicated O&M division to manage the inevitable inverter replacements and array cleaning required over time.