Posted by David R. Wetzel, Ph.D.
Solar Water Distiller
Students use hands-on inquiry based science to investigate the water distillation process using solar energy.
The purpose of this experiment is to determine if pure water can be distilled from dirty water.
Materials: (Per Group of Students)
1 Large Clear Plastic Container
1 Small Glass
1 Small Rock
1 Tablespoon
2 Tablespoons of Dirt
Clean Water
Duct Tape
Clear Plastic Wrap
Hands-On Procedures:
1. Tape the empty glass to the bottom of the large clear bowl, open side up.
2. Add water to a point below the glass opening, ensure clean water does not enter glass.
3. Add 2 tablespoons of dirt to water and stir.
4. Cover opening of bowl with plastic wrap and place small rock in center.
5. Place completed bowl setup in sunny location or use a heat lamp if sunny location is not available.
Inquiry Based Hypothesis Development and Discussion:
1. Students predict if the outcome of the experiment during construction of their Solar Water Distiller.
2. Students make observations of their Solar Water Distiller for 5 days.
3. Students discuss the outcome: Was their hypothesis supported? What evidence do they have to support their findings? What would happen if salt was used instead of dirt? What about sugar?
Posted by David R. Wetzel, Ph.D.
Solar Energy Transformation
Simple demonstrations of solar to energy transformations allow students to investigate energy transformations into other types of energy. Examples include: solar to heat, solar to electrical, chemical to electrical to mechanical, mechanical to electrical to heat, etc.
The following investigation is safe for students to study energy transformations.
Solar to Electrical to Heat Energy Transformations
The image demonstrates solar energy being transformed into electrical energy (solar panels). The electrical energy is then transformed to heat energy as it heats the water in the tank (red color in in tank indicates cold water transformed to hot water by electrical heating strips in the bottom of the tank).
This can be investigated in the classroom by doing the following:
Materials -
Small solar panel, thermometer, small beaker or clear cup, water, and 1.5 feet of non-insulted wire, bright flashlight (if do not have access to sunny window)
Introduction -
Hold a class discussion about energy transformations: however, do not focus specifically on the transformations in this investigation. The discussion needs to be on all types of energy transformations, allowing the students to guide the discussion and share what they know in advance from prior knowledge and experiences (PKE).
Procedures -
- Fill beaker half full of water
- Measure the temperature of the water with the thermometer and leave thermometer in water
- Connect each end of the non-insulated wire to the solar panel
- Coil the looped end of the non-insulated wire four times and place into water
- Shine bright flashlight (or sun light) on solar panel
- Record the temperature of the water over a period of several minutes
Sample Questions to Ask Students -
- Ask students to explain what happened and evidence to support their explanation.
- What type of energy transformations occurred and their evidence to support their answer.
- Ask students how or where their findings in this investigation influenced by their PKE.
- Ask students to explain any examples of potential and/or kinetic energy.
Options -
- Students form a hypothesis based on PKE.
- Students measure time of temperature changes with a stop watch.
- Students draw a graph of the temperature changes – indicating independent and dependent variables.
- Students explain control and uncontrolled variables.
Resources
The following resources can be used to support this investigation:
Understanding Scientific Inquiry
20 Questions to Ask Students in Science Projects
Writing in Science
FT Exploring Energy Transformations
