Quick Answer
A solar still may fail to produce water if the collection container does not have a sufficient slope, preventing the condensed water from flowing into it. Alternatively, if the still's surface area is too small, there may not be enough evaporation to produce a significant amount of water. Additionally, a still that is shaded or covered may not receive sufficient sunlight to facilitate evaporation.
Insufficient Slope
A solar still requires a collection container with a gentle slope to allow the condensed water to flow into it. A slope of at least 1-2% is recommended to ensure that the water flows into the container efficiently. If the slope is too shallow, the water may not flow into the container, resulting in a failed still. To achieve the correct slope, use rocks or sand to create a ramp leading into the collection container.
Inadequate Surface Area
The surface area of the still’s water reservoir or evaporation surface is critical in determining the amount of water that can be produced. A larger surface area allows for more evaporation, resulting in a greater amount of water being collected. A good rule of thumb is to maintain a surface area of at least 1 square meter (10.7 square feet) for a small still. This can be achieved by using a larger container or by creating a series of shallow pans.
Shading and Sunlight
A solar still requires direct sunlight to function effectively. If the still is shaded or covered, it will not receive enough sunlight to facilitate evaporation, resulting in a failed still. To ensure that the still receives sufficient sunlight, choose a location that is exposed to direct sunlight for most of the day. Avoid areas with dense vegetation or other obstructions that may cast shade on the still.
Find more answers
Browse the full Q&A library by topic, or jump back to the topic this question belongs to.