There are a lot of ways to use the sun! Solar panels are a staple in solarpunk artwork, but when your goal is to make heat or light, converting sunlight to electricity and back again actually wastes a lot of the energy. Here are a few low(ish) tech alternatives that might be a better fit for the circumstances in your story or artwork:

Fresnel Lenses are a type of large, flat lens designed to focus light. They use a circular pattern of cuts which simulate the surface angles of a much thicker lens while remaining quite thin. This allows for a huge surface area and very low mass, making them very useful in everything from light houses to rear-projection televisions. There are a variety of interesting projects built around these lenses:

• A 3D printer for sintering sand into glass objects
• A solar rig for smelting zinc or aluminum
• It seems likely that these could be used for solar forging, glassblowing, or perhaps even CNC sheetmetal cutting with enough focus. There are a variety of videos online of people using fresnel lenses from a rear-projection TV to burn through steel skillsaw blades and to melt sand into glass cabochons.