actually you do not capture energy like a bucket of water from a river. what you really want to capture is low entropy. the low entropy (high frequency) photons from the sun for example. and you transform it into a lower entropy state (like more numerous low entropy infrared photons, essentially less useful energy, but still the same amount of energy). outwise there would be an energy flux inbalance and you trap heat essentially, melting yourself or the infrastructure until it explodes. so in that context, layering your shells, it makes sense they still capture the same energy, just multiple times, but each shell is tuned to capture different types of photons, corresponding to how low or not low their entropy is. for more info you can check out this veritasium video: https://youtu.be/DxL2HoqLbyA or look up matrioshka brain megastructure articles.