> they have pioneered robotics, process engineering, cutting edge trains, and electric/hydrogen/hybrid automotive A common theme among these technologies is th

> they have pioneered robotics, process engineering, cutting edge trains, and electric/hydrogen/hybrid automotive A common theme among these technologies is that they make for lucrative business. Automotive business is big, robotics and process engineering make for better yield (as for trains, maybe they just have passion for trains). Not so for clean energy. Japan had a large chunk of energy generation coming from nuclear power until 2011 so there wasn't any incentive for looking for alternative solutions as what they had was already clean and cheap. It's been 10 years since the disaster but I think that is still not enough time for them to have an alternative solution running.