Very little in life is free you will have to work at getting them. A company letter head and a projected sales volume will probably get them interested in giving you some samples but your presentation will have to look professional.
Good luck
http://www.photowatt.com
Send Email to Photowatt International S.A.
http://www.npowercanada.com
Send Email to Npower Energies
http://www.china-solarpower.com/sdp/110301/4/main-1000013.html
Send Email to Shenzhen Xinhonghua Solar-Energy Co., Ltd (Representative:Angel)