Guardian: Fidelity Investments is the world’s biggest investment manager. It has more than $1tn in its custody, and its hard-nosed managers scour the world to exploit the best profit opportunities. It believes in the efficiency of free markets. Pinko-lefty Guardian types are thin on the ground. Yet the organisation recently sent five of its top money managers to a solar-power conference in Spain, not because it wants to tackle climate change, but because it believes solar power will be a …