Most solar energy vents operate exactly like regular vents, but instead of being powered by the wind, they generate energy from the sun. A regular wind-driven vent will not operate on a hot, still summer day. A solar vent will work all year round.
Home appliance vents are a generic term used to cover all supply and return air sources connected to a central air-conditioning system. All registers, grilles, and returns are vents. Home and building owners don't need to know the difference between air registers and grilles.