By Christoph Steitz and Nina Chestney FRANKFURT/LONDON, July 7 (Reuters) – Siemens Energy’s (ENR1n.DE) disclosure of quality issues in its newer wind turbine models has exposed broader challenges in a sector suffering from rushed development, soaring materials costs and a flawed market design. Siemens Energy shocked the wind sector in late June when it warned of faulty components and possible … Read more