Plastic Bottle Lights

Plastic Bottle Lights are a solar lighting solution that refracts sunlight through a water-filled PET bottle to provide free daytime interior lighting for dwellings, without requiring electricity. Installed through a roof, the device channels natural daylight into otherwise dark interior spaces, providing the equivalent of up to 55 watts of light during daylight hours.

The light bulb itself is built from a large, clear PET bottle with its lid, mounted into a 10 x 10 inch section of corrugated galvanized iron roofing sheet. Using a knife and jigsaw (tin snips and a permanent marker are also used per the manual), a hole is cut in the center of the roofing sheet with 32 radial tabs cut and bent perpendicular to the sheet to form a locking seal. The bottle surface is sanded where it will contact the roofing sheet, then inserted through the lock until the tabs meet the sanded surface. Sealant is applied around the joint and left to dry. The bottle is then filled with 10 ml of bleach (to prevent algae growth) and topped up completely with water before the cap is tightened.

To install, a hole matching the bottle's size is cut into the roof at the chosen light location. External sealant is applied around the hole, and the assembled bottle light is inserted with the bottle cap facing upward, ensuring the roofing corrugations align and seal securely. Four holes are drilled through both layers of roofing sheet on each side of the bottle and secured with rivets, with sealant applied along all edges and over the rivets to prevent leakage. A protective plastic tube is placed over the bottle cap and sealed to complete weatherproofing.

Levels are identified based on this reference: Field Ready Readiness Levels

About the manuals

Field Ready develops manuals to support both the fabrication and safe use of its products. A maker manual provides step-by-step instructions for replicating the design, including materials, tools, and assembly guidance, so that makers in different locations can build the product accurately and consistently. A user manual, where applicable, explains how to properly set up, use, and maintain the product once it is built, helping ensure it performs safely and as intended for the end user. Together, these manuals make the design accessible to both fabricators and the people who ultimately rely on the product.