Tilt Angle (of a Solar Collector or Module) 1 topic · 1 source ScienceEnergyThe angle at which a solar collector or module is set to face the sun relative to a horizontal position. The tilt angle can be set or adjusted to maximize seasonal or annual energy collection.US DOE Office of Energy Efficiency & Renewable Energy — Glossary of Energy-Related Terms retrieved 2014-05-26 Cite