What is average sales commission for solar power sales?

I have been a director of sales and VP of sales at several solar installers. Residential solar salespeople, or design consultants, can be paid in a variety of methods; full commission (most common), recoverable draw plus commission, non-recoverable draw plus commission, or base salary plus commission. The commission will typically be greater if there is no base salary. Expenses, such as mileage, will vary as well. Many companies offer salespeople benefits. The benefits and expenses make a big difference in quality of life.
The most common, full commission range 5% to 7.5% depending on if self-employed, volume of business, bonus plans, mileage reimbursement, etc.

Recoverable or non-recoverable draws typically range $2k-$3k month; commissions will be in the same range as if on full commission.
Base salary can range $2k-$3.5k per month. The commission schedule will most likely be lower with a base salary; range 3% to 5%.
Conclusion; no matter the method of payment, a successful residential solar salesperson or design consultant can make $60,000 to $300,000. The large difference is due to the company's offerings, available financing, number of leads, geographic location, available rebates or state tax incentives, and most importantly, the individuals knowledge, experience and sales ability.

Good luck.