In 2009-ish China announced subsidies of basically half the cost of any large scale solar installations. The Chinese government has been giving solar companies below market rate loans. According to Scientific American China chipped in $47 Billion to build its solar industry.

This is, of course, in addition to the standard protectionist industry subsidies like the Joint Venture rules, subsidies on raw materials like steel, or transportation of such goods via rail, etc.

[1]: https://www.scientificamerican.com/article/why-china-is-domi...