Wind turbines!
This example is immensely funny to me, since in the 90s the NSA stole trade secrets related to wind turbines from the German company Enercon and passed it on to the US company Kenetech, who then managed to get a patent in the US.
English sources are a bit scarce, but here's an article that references it:
> Some months later, a former NSA agent admitted that the organisation had secretly intercepted Enercon's data communications and monitored conference calls. The NSA passed all the information it gleaned on to Kenetech.[1]
There's also a report on ECHELON for the European parliament that mentions this case among others[2]. Some more cases became known through documents leaked by Snowden.
To complete this circle German intelligence services would now have to steal trade secrets related to wind turbines from China, but sadly they're explicitly forbidden from conduction industrial espionage - to the chagrin of German companies who are feeling disadvantaged.
[1] https://www.irishtimes.com/business/electronic-spies-torture...
[2] https://irp.fas.org/program/process/rapport_echelon_en.pdf