Add a solar system to existing consumer unit

Hi All,

Getting quotes for a solar and battery system. The first company sent just a sales man so he wasn’t much help for this query. Just wondering if the electrical equipment can be added to my existing consumer unit. I was looking at my brothers system a few days ago. They put up a 2nd consumer unit beside the existing as it was fairly full. The solar CU has a double isolator, double surge protector, double rcbo, single mcb, a single solar check meter and a double power sensor. That’s 10 spaces full. 

In my CU have roughly that space left between the 2nd and third row. I already have a double surge and double isolator. Would that mean I wouldn’t need those and the installers would use only 6 spaces? I’d like to avoid a 2nd consumer unit if possible with the possibility of any future additions.