Hey there Aymmugan Aynkaran! When it comes to estimating peak power demand for buildings, both EnergyPlus and TRANSYS are powerful tools, but they serve different purposes.

EnergyPlus is primarily used for whole building energy simulation. It considers factors like HVAC systems, lighting, and other energy-consuming components. It's robust for assessing the overall energy performance of a building under various conditions.

On the other hand, TRANSYS, as you Aymmugan Aynkaran mentioned, is often associated with solar energy systems. If your focus is on incorporating solar cells and analyzing their impact on peak power demand, TRANSYS might be more tailored to your specific needs in that regard.

In the general scenario of estimating peak power demand for a building, especially if you're looking at a holistic view of energy consumption, EnergyPlus could be a more comprehensive choice. It takes into account a wide range of building systems and components.

However, if your emphasis is on the integration of solar cells and optimizing for renewable energy sources, TRANSYS might provide more detailed insights into that aspect of the building's energy profile.

Ultimately, the choice depends on the specific requirements of your project and the aspects you prioritize. Both tools have their strengths, so consider the key factors influencing your analysis to make the most suitable decision.

TRANSYS softwares is good to estimating peak power demand for buildings.

Both are good enough!