According to the CSI database, which tracks systems from Jan. 2007 to date, the top 10 residential and small commercial (< 10 kW) installers are listed below. This data is based on Reservations Requested, not requests completed:

1. SolarCity
2. REC Solar, Inc.
3. Akeena Solar, Inc.
4. Borrego Solar Systems Inc.
5. SPG Solar, Inc.
6. REgrid Power, Inc.
7. Acro Electric, Inc.
8. Marin Solar, Inc.
9. Sun Light and Power
10. Advanced Solar Electric, Inc

However, this is a bit misleading because Real Goods Solar has recently purchased REgrid, Marin Solar and 2 other companies. Real Goods is now actually #2 or #3 if you include the projects installed by companies it has acquired. Borrego recently sold its residential division to groSolar.

On the commercial side, the top 10 are:

1. SunPower Corporation, Systems (more than 2x as big as the next biggest)
2. SunEdison, LLC
3. Chevron Energy Solutions, Inc.
4. Team-Solar, Inc.
5. SPG Solar, Inc.
6. Chevron Energy Solutions
7. REC Solar, Inc.
8. Conergy Projects, Inc.
9. Borrego Solar Systems Inc.
10. BP Solar International, Inc.

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