unforeseen plant outages or forecasting errors related to electricity generation require that a higher amount of spinning reserves be carried out uncertainties in vre power production may also lead to an increase in ramping and cycling of conventional power plants to inefficiencies in plant scheduling and overall to higher costs for the system while all generation plants may have some siting restrictions the impacts are more significant for vre also high shares of distributed pv resources may require sizeable investment into the distribution network in particular to allow the inflow of electricity from the producer to the grid when the electricity generated exceeds demand