The usage of photovoltaic systems began around 33 years ago and theses systems are still working just fine until today. Solar technology has gone through major development and improvement, which enables today’s solar systems to work for 40+ years while generating more electricity then ever before. As a rule of thumb, the solar energy systems’ power output decreases approximately 2% per year. The warranty on these systems is usually 5 years (manufacturing) and 25 years of 80% output (power production) on the solar modules and 10 years on the balance of system installation.