Hello,  
I mapped the ground-mounted mega solar plant here.  
This site used to be a golf course, but it has now been converted into a solar power facility.  
According to Esri aerial imagery, the clubhouse has been demolished.  
Therefore, Esri seems to be more up-to-date than Bing in this area.  
The small surrounding structures appear to be related to the solar facility equipment,  
so mapping them as buildings is not appropriate here.