A few years ago we’d expected technological progress on solar module efficiency to slow as theoretical maximum efficiency limits drew near. Instead, the doubling of the industry every couple of years allowed R&D budgets, and results, to keep coming even faster than before. The ferocious competition to stay in the top 50% of manufacturers for cost-effectiveness (or be unable to sell and go out of business due to overcapacity) has also helped. That’s why the SNEC exhibition in Shanghai, the biggest event in the solar industry – held last week – now features multiple solar modules with over 25% efficiency as one of its headline attractions, alongside an increasing prevalence of co-located battery storage systems. To name a few examples,…