http://dailycaller.com/2017/03/01/solar-panels-increased-emissions-of-a-gas-17200-times-more-potent-than-co2/

New federal data shows a potent greenhouse gas — that’s also a byproduct of solar panel construction — is on the rise.
Nitrogen trifluoride (NF3) is a key chemical agent used to manufacture photovoltaic cells for solar panels, suggesting government subsidies and tax credits for solar panels may be a driving factor behind the 1,057 percent in NF3 over the last 25 years. In comparison, U.S. carbon dioxide emissions only rose by about 5 percent during the same time period.

http://news.nationalgeographic.com/news/energy/2014/11/141111-solar-panel-manufacturing-sustainability-ranking/

Fabricating the panels requires caustic chemicals such as sodium hydroxide and hydrofluoric acid, and the process uses water as well as electricity, the production of which emits greenhouse gases. It also creates waste. These problems could undercut solar's ability to fight climate change and reduce environmental toxics.