When two U.K. power plants shut down almost simultaneously in London’s first major blackout for a decade, it triggered a storm of questions about how to avoid another failure. As National Grid Plc, the regulator Ofgem and plant operators investigate what happened, last Friday’s failure underlined the need to bolster an electricity grid increasingly fed by intermittent flows from renewables such as wind and solar. One way is by encouraging construction of new storage assets such as hydropower and batteries that can be called upon almost instantly. “The power outages boost the case for better system flexibility in the ... (full story)