When coupled with solar, batteries are absolutely a net producer of energy. Around the clock too, as it allows solar generated at low-demand times to be redeployed when needed most.
That could be true, but I think important to clarify
- how big is the solar array and how big is the battery?
- what does the consumption look like
- is your battery big enough to help navigate through a week of cloud cover in winter?
- do you live somewhere with great solar resource