The price of solar panels has plummeted 50% over the past year, largely, industry insiders say, because of deliberate Chinese overproduction of key components and a game of international cat-and-mouse over trade rules often likened to a game of “Whac-A-Mole”. As different sets of rules get established, Chinese companies have proved adept at moving their manufacturing plants to other countries, in south-east Asia, and shifting strategies to work around US tariffs and other deterrent measures.