As PV Expo rolls into Tokyo for its eighth outing this month, it coincides with what has been a pivotal time for solar in Japan. Behind the headlines of explosive growth over the past couple of years, some darker currents have been swirling that have threatened if not to bring the wheels off, then certainly to prompt questions over the longevity of Japan’s solar success story.

PV deployment continues to grow at a remarkable rate. In just under 15 years it has gone from being a niche player, with a little over 1GW installed worldwide, to almost 140GW last year – more than a 10,000% increase. The technology’s onward march looks set to continue well into the future, albeit at a slightly more measured pace, with estimates forecasting as much as 430GW worldwide by 2018.