The comments below have noted that this is like a solar tube or deck prism.
The communities who benefit from this idea live in areas where the houses hardly have windows and live in darkness even during daytime. Their solution up until this innovation was to turn on the light bulb and use electricity.
*PET soda bottle
*Galvanized Iron (GI) sheet
Step 1: Cut approximately 9 x 10 inches of GI sheet (corrugated or flat)
*Here is a how-to video
Step 2: At the center of the GI sheet, draw 2 circles
Step 3: Cut the 1 cm difference radially, making strips and bend upwards, perpendicular to the GI sheet
Step 4: Using sandpaper, scratch the surface around the upper third portion of the soda bottle where the GI sheet will be placed, to allow the rubber sealant to stick better
Step 5: Insert the bottle into the GI sheet until the upper third. Apply rubber sealant on the strips above and around the area below. Wait to dry
Step 6: Fill the soda bottle with filtered water and ~10 mL (2 capfuls) of bleach. Cover with its original cap
Step 7: The solar bottle bulb is now ready for installation!
(Proceed to next step for the installation.)