This paper describes the core model that lies behind an online modeling environment for photovoltaic (PV) energy generation in the Netherlands, called the Dutch PV Portal 2.0 (PVP 2.0). PVP 2.0 realizes three functionalities: (i) a real-time system efficiency breakdown figure, (ii) an estimate of national solar electricity production, and (iii) an economic analysis for small-scale to large scale PV systems. The unique and novel aspects of this website are the dynamically updated climate database, the rainfall-dependent soiling loss calculation, and the orientation-dependent inverter sizing factor. This paper also justifies the PVP 2.0 capabilities in large scale studies. First, the PVP 2.0 modeling approach was validated by yield comparison with 26 real PV systems distributed over the Netherlands. The validation resulted in −11% to +5.5% deviation from measured data. Then, a back-end sensitivity study found that a rain-free summer in the Netherlands results in an AC energy loss of 3.4% in that period, while a change in wind speed or ambient temperature could lead to losses around 2–4.5 GWh/year (0.58%–1.16%) on province scale. The core of the approach presented in this paper can be used to develop similar websites for other countries of interest with adapted add-ons depending on the target climate condition. Such study tools could eventually provide more quantitative insights about the impact of climate change (by applying probable scenarios) on the renewable energy production of the World.