Tesla has announced plans to build a factory in Shanghai to produce its Megapack energy storage system. Photograph: Qilai Shen/Bloomberg Tesla has announced plans to build a factory in Shanghai to produce its Megapack energy storage system, as chief executive Elon Musk resists rising opposition in Washington to US technology companies investing in China. Tesla’s Megapack system provides lithium-ion battery packs to help store renewable energy for electricity grids and represents a key driver for its energy storage and generation business. The electric-vehicle maker said at a signing ceremony in the Chinese city that construction of its new plant was...