Energy system models often rely on assumptions about the infeed of renewable energies. Despite their significance, the renewable time series are often based on single weather years, selected without applying clear criteria. For planning purposes of photovoltaic plants or heating and cooling systems, it is common practice to artificially create weather years composed of months from different years. However, there are only few models for the composition of artificial weather years that represent a well-defined high- or low-infeed-scenario. A new method is proposed to artificially construct infeed time series on system level. Under the assumption of a normal distribution, we compose an infeed time series which aims at meeting a certain quantile of annual infeed. Thus, it is possible to construct different infeed scenarios, to model the inter-year variability of the renewable infeed. The method at hand can be useful for everyone who uses exogenous infeed time series in energy modeling.