Bungie has revamped Solar in Destiny 2. Scorch and Ignition are two new keywords to pay attention to. Different weapons and mods can impact how the element behaves in combat. But before we get to tinkering, we need to know the base definitions.
Destiny 2: Solar 3.0 Ignition Explained
Ignition is a large Solar explosion that deals damage in an area around the target. It can be triggered by applying Scorch to a target. Scorch is applied when a target is singed by destructive Solar Light and takes damage over time. Scorch damage increases as the target accumulates more Scorch stacks. After enough Scorch stacks are applied to the target, they ignite.
Weapons like the Exotic Trace Rifle Prometheus Lens will apply Scorch to a target, which can then cause them to Ignite. Weapons like Ace of Spades and Sunshot will mimic Ignition but are technically their own effects (Firefly and Sun Blast, respectively). Mods like Ember of Char will cause the Solar Ignitions to spread Scorch to affected targets as well. Season of the Haunted is all about starting a fire and making it spread as fast as possible.
For more Destiny 2 goodies, check out Destiny 2 Leviathan Map – All Derelict Leviathan Locations on Pro Game Guides.