The U.S. solar industry saw a heavy slowdown in 2017. The utility sector returning from orbit after their massive 2016, and a market evolution away from leases toward cash purchases caused a 16% tightening in residential. The commercial market bucked the trend though and grew from ~1,650 MW to ~2,100 MW, about 28%.

GTM Research defines a commercial solar project as one that isn’t a residential deal, and also doesn’t sell its electricity to a utility. The direct off-taker of the project drives this decision, not a PPA buyer offsetting their usage, meaning many corporate buyers of solar electricity are left out of this list.

The list of 15 companies totals just over 1,000 MW of projects participated in.

Asset Owners and Project Development dominate the list, while Engineering Procurement and Construction (EPC) groups – the people actually building the plants – seem to be more locally focused and less apt to scale in the commercial market. The top five companies on the list most likely don’t have a contractor license, and hire local general contractors to subcontract projects.

The ~1 GW of solar projects that these groups participated in don’t necessarily represent unique projects.

The list is a big contrast to top 500 Commercial Solar Contractors provided by Solarpowerworldonline.com. This list is self reported volumes, and those on the list pay to be on it. SunPower showing 1 GW on this list, versus 231 MW on GTM Research shows that volumes are being mixed between sectors – or that definitions are different, but either way it shows SunPower is a big player.

The Solar Power World list also shows that the breadth and depth of the commercial market is far beyond this GTM Research that is focused on the activities of the top 15 companies. Smaller to medium-sized projects in this sector tend to be financed by local bankers, and ‘developed’ by the local solar EPC as they work through the process directly with the building owners.

Interestingly, if Tesla does build a 70 MW solar power plant on its Gigafactory, that alone would get it 6th place on this list.