Nobody needs that, but from my point of view batteries will be so cheap and abundant that we will likely get to having 2 weeks of storage just sitting around the grid or rolling on wheels.
People always underestimate where exponential cost decreases will take us. Current battery production grows by 10x in a mere 5 years. In a decade, the time it takes to build a nuclear power plant, we will grow our battery production by 100x. Not enough people take this seriously, or even know that the trend exists.
How would 2 weeks of battery help you in that situation? The winter lasts a lot longer than 2 weeks. So after 2 weeks of no sun, wouldn't you be just as screwed as if you had 1 week of battery storage?
People always underestimate where exponential cost decreases will take us. Current battery production grows by 10x in a mere 5 years. In a decade, the time it takes to build a nuclear power plant, we will grow our battery production by 100x. Not enough people take this seriously, or even know that the trend exists.