This article explores problems related to designing and developing the system to predict renewable energy (or similar projects) - the outcome of the presented project is a web application (not a desktop app). Many things have to be considered, like the optimal technologies, team composition, budget, timetable. It might be helpful for you to read this article before you choose to develop a similar system, as otherwise, it can cost you a lot of time and money.
Many open-source tools can help with the prediction of renewable energy production. For example, the Python library PVLIB for computation of production solar of photovoltaic panels implements essential scientific methods. However, if it comes to predicting energy from wind turbines, there is no similar library - but the computation itself is sufficiently simple - so everyone can write their methods. There is also a question of how precise predictions are, which requires a probabilistic approach.