The new entrants are examples of a green-energy spending binge in China that is fueling the country’s rapid build-out of renewable energy while also creating a glut of solar components that is rippling through the industry and stymying attempts to build such manufacturing elsewhere, particularly in Europe. Since the start of the year, prices for Chinese polysilicon, the building block of solar panels, are down 50% and panels down 40%, according to data tracker OPIS, which is owned by Dow Jones. Inside China, some companies fear a green bubble is about to pop. China’s state-guided economy spent nearly $80 billion…