High efficiency skylight systems are one way to optimize natural sunlight to increase your building's energy efficiency. Many new buildings are now designed to do this.
However, if you own or manage an older building that has not been designed to optimize the natural light provided free by the sun, then consider retro-fitting high efficiency skylights. You could also consider integrating high efficiency skylights with automatic light control systems. It's a great way to optimize your lighting and save on energy costs.