If you are buying a TV in an appliance store, the maximum guarantee that you should expect is 1 year. Maybe 2 if you buy an extension. When purchasing a renewable power plant, you are buying a 20 year guarantee product. Thats why its critical to request references. Before buying or entering into a contract with a solar company, I do advise to get at least three quotes from different companies. I have done 3 projects with Mardel Souza and recommend them widely. Also you should ask if the company has engineers in staff, how many years they have been in business and a list of references to call. I met them 8 years ago and they are still offering the same products and services. They offer 20 year guarantee and represent companies from Texas and Arizona. Definitely recommend for residential, commercial or small industrial. Feel free to contact me for any reference. Chris Hamby 956) 495-6953