Educational 14 October 2025
Let’s play a little free association. I say “lighting.” You say… “bright,” right? Maybe “illumination” if you’re feeling fancy. And you’re not wrong—there are no wrong answers here!—but the reality is, brightness only scratches the surface of what lighting does and how it makes spaces feel.
Just as important is distribution, or how a fixture directs and spreads light across an area. It affects visibility, uniformity, and comfort, and ultimately determines whether outdoor spaces like streets, pathways, and parking lots feel safe and welcoming or patchy, harsh, and unpleasant.
Sol’s solar lighting systems pair with a wide range of Acuity fixtures, giving you the flexibility to choose the ideal light distribution for your project. Whether you need broad, even coverage or focused illumination with minimal glare, you can choose the distribution that best meets your site’s needs.
All light fixtures are designed with optics that determine how light is cast from the fixture onto the ground. Some project long, narrow beams that are ideal for roadways and pathways, while others form wide, circular pools better suited to plazas or parking lots.
The Illuminating Engineering Society (IES) defines five standard distribution types used in outdoor lighting design:
Type I: Long and narrow
Type I distributions create a tight, rectangular beam, best suited for linear paths. They’re often used along walkways and sidewalks where the goal is to light length without spilling over or “coloring outside the lines.”
Type II: Wider coverage
Type II expands the beam outward, offering slightly more width. It’s a good fit for narrow roadways, alleys, and side streets where both the road its surroundings need light.
Type III: Wide forward throw
This pattern projects further out in an oval shape, providing broad coverage for wider roadways and parking lots. The forward throw helps light reach across spaces without requiring additional poles.
Type IV: Tight forward throw
Type IV distributions cast light forward in a tighter beam, ideal for lighting the edges of parking lots and building perimeters. The design delivers strong forward coverage without wasting light behind the pole.
Type V: Circular
Type V throws light evenly in all directions, forming a circular footprint. It’s a good choice for intersections, public plazas, and areas that need a lot of light.
At first glance, choosing a distribution might seem inconsequential (a light is a light is a light… right?). But the implications are significant:
In solar lighting, distribution not only affects visibility and comfort but also how efficiently each system uses its stored energy. A poorly matched pattern can waste light on unneeded areas, requiring larger, more expensive systems with additional solar panels and batteries.
Choosing the right distribution ensures that every watt of solar energy is used effectively, reducing system size and cost while maintaining consistent, reliable light levels throughout the night.
Light distribution is easy to overlook, but it has a big impact on safety, energy use, and the overall feel of a space. With Sol’s solar systems and Acuity’s fixture options, it’s simple to choose a pattern that fits your site—and makes every lumen count.
Have questions about light distribution patterns, or anything else? Our team is here to help.
