Comment by Haemm0r

The battery increases the upfront cost but also increases the roi very much (at least where I am living). You get way less money for feeding energy to the grid than you have to pay for withdrawing energy(as you said some utilities even limit/forbid feeding during peak hours). In my case that means (Austria): Sell 1 kWh - 0,04€ Buy 1 kWh - 0,25€