I would take this with a grain of salt, but it is a starting point for reference. This is based on excellent solar conditions.To charge a Specialized Turbo Creo 2 in 4 hours during a Central Oregon summer, you need a solar setup capable of delivering a consistent 80W to the bike's 320Wh battery.

The Recommendation

• Panel Size: A 200W solar panel is ideal. While a 100W panel exists, a 200W unit provides the necessary "overhead" to overcome efficiency losses caused by high-desert heat and conversion.
  
• Physical Dimensions: * Rigid Panel: Approximately 150 cm x 67 cm (59" x 26.5").
  
  • Portable Folding Panel: Roughly 60 cm x 55 cm when folded (briefcase size), extending to 225 cm (88.5") when fully deployed.
    

Key Takeaway Central Oregon offers excellent sun (6.5+ peak hours), but the high temperatures reduce solar efficiency. Choosing a 200W monocrystalline panel ensures you hit your 4-hour charging window even on hot afternoons.