The amount of hours lost due to extended maintenance is therefore between 60 and 120 hours, which represents a loss of 0.7-1.4% of the availability factor. Additional studies performed by EPRI and a Slovakian operator concluded that load cycling should have an impact on O&M, but no statistically significant effects were observed. The economic aspects of load following have received increased interest due to the extreme price volatility induced by variable renewables (including negative prices) in countries with large shares of renewables, such as Germany.