This case study demonstrates the successful implementation of an illustration-based design with a modern look for Heyvolt, a smart energy assistant. By combining modern aesthetics, custom illustrations, and a user-friendly interface, Heyvolt achieved its objective of providing an engaging and visually appealing solution for homeowners with solar panels. The design approach enhanced user engagement, promoted a modern brand identity, and delivered a positive user experience that aligned with Heyvolt's innovative and forward-thinking vision.