A stable energy system based on solar, wind and storage does not necessarily require full seasonal storage. When generation, demand response and grid management are designed together, several days of battery storage can already play an important role in reliability and balancing.
The key point is that storage should not be sized in isolation, but within the whole energy system. For Gelderland, this means combining renewable generation with flexible demand, smart contracts, grid steering and spatial planning. Storage then becomes part of system design, not only an extra battery next to production.