I don't think the solar industry is very healthy right now. There has been a glut in supply for years and some high profile companies have gone out of business. Anyway look up the companies you are interested in. Do a news search on the companies and the industries. When you meet with them try to apply some of what you learned from the news to ask well thought out questions to get an idea of what the company may be facing in the short and medium term. Good luck!