As with any mass manufacturing technology, we climbed S-shaped learning curves. There is a substantial literature; search for "learning {curve|rate} {wind power|solar pv|renewable energy}"[1]. A simple explanation to the concept [2]. For solar, it's mostly silicon manufacturing techniques, a sort of distant cousin of the techniques used to manufacture your laptop's CPU. For wind it's that but also design (you want VERY tall towers geared for maximum efficiency at somewhat below median winds IIRC) and especially construction. The techniques for getting giant blades to site are not trivial; the techniques for building off-shore turbines are embodies in some of the world's more sophisticated engineering companies.

[1] https://scholar.google.com/scholar?q=learning+curve+analysis... [2] https://www.energytoday.net/economics-policy/credit-renewabl...