About Photovoltaic (PV) systems: are you concerned by PhotoVoltaic efficiency?
Here is the case of PV panels when located in shadowed zones due to the environment, there are many buildings within cities in such situations.
Solution is to integrate in each PV module one micro inverter instead of having only an inverter linked to the whole system of PV modules. Each micro inverter will take the maximum power of each individual module without impacting the other module and the production will be fully optimized always.
Lots of small companies are offering such systems:
Enphase Energy technology,
Last issue is a quality issue: is this new technology reliable enough ?, debate is open: