The method is applied to a Portuguese case study and results show that coupled scenarios based on the strategic combined development of wind and solar generation provide a more sustainable way to increase the share of variable renewables into the power system (up to 68% for an. . The method is applied to a Portuguese case study and results show that coupled scenarios based on the strategic combined development of wind and solar generation provide a more sustainable way to increase the share of variable renewables into the power system (up to 68% for an. . Abstract: Understanding the spatiotemporal complementarity of wind and solar power generation and their combined capability to meet the demand of electricity is a crucial step towards increasing their share in power systems without neglecting neither the security of supply nor the overall cost e. . In this transition process, wind and solar photovoltaic (PV) technologies, due to their available resources and the investment costs, will play a key role in the energy matrix of the next decades, as projected in the Portuguese National Energy and Climate Plan for 2021–2030 (NECP 2030) and the. . Understanding the spatiotemporal complementarity of wind and solar power generation and their combined capability to meet the demand of electricity is a crucial step towards increasing their share in power systems without neglecting neither the security of supply nor the overall cost efficiency of. . In this regard, this paper proposes a stacked ensemble algorithm (Stack-ETR) to forecast PV output power one day ahead, utilizing three machine learning (ML) algorithms, namely, random forest regressor (RFR), extreme gradient boosting (XGBoost), and adaptive boosting (AdaBoost), as base models. In. . In this transition process, wind and solar photovoltaic (PV) technologies, due to their available resources and the investment costs, will play a key role in the energy matrix of the next decades, as projected in the Portuguese National Energy and Climate Plan for 2021–2030 (NECP 2030) and the. . Numerous studies have shown that the combination of sources with complementary characteristics could make a significant contribution to mitigating the variability of energy production over time. This article aims to evaluate the optimal configuration of a hybrid plant through the total variation. .