BATTERIES, ELECTRIC vehicles, demand response and interconnection with Nordic hydro will make U.K. and German power systems cheaper and cleaner (WK-intern) - New forms of flexibility key to an affordable, renewables-led power system London and Berlin – Flexible energy options, such as energy storage, smart-charging electric vehicles, demand response and interconnectors, are needed to ensure that the energy transition proceeds on an optimal path. Our expensive power system would otherwise be reliant on fossil-fueled backup and installing excess wind and solar capacity. The four types of flexibility mentioned above can accelerate the transition to a cleaner power system and ultimately enable the efficient integration