Solar-Powered Lamp

This lesson teaches the basics of photovoltaics. It ends with the construction of an LED lamp, powered by a battery that can be charged with a solar panel.

This lesson could easily be split into two: a solar-powered battery charger and an LED lamp.

If this lesson interests you, there's lots to do:

• Write the teacher's guide
• Adapt the default evaluation form
• Design and upload illustrations

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Charger: Practical basics of photovoltaics, science of batteries, how to build a charging circuits, diodes

Lamp: LED science, illumination and lighting design

soldering

Brainstorming, “build an effective lamp” or “focus the light in this way”

Possibly teamwork

Students build a solar charger, as well as a lamp powered by rechargeable batteries.

PEN lessons that meet the requirement are noted in brackets.

basic circuits (possibly this is the intro lesson?), how batteries work (battery), parallel and series (battery)

can understand circuit diagrams– or, at least, follow instructions

large-scale solar, re-design the lighting system for your house?

Teacher demonstrates the sensitivity of a solar panel by measuring its voltage in the sun, in the shade, and in the dark. To illustrate light refraction, teacher shines a light into a full water bottle.

Students can wander around testing the voltage of their solar panels. Students could also calculate efficiency of panels.

Perhaps the teacher creates a dark room, and students see how they can use the light of one flashlight most effectively.

Students will design and then build lamps using found reflectors and diffractors. They could follow instructions for the charging circuit.

Lamp construction materials such as glue, wood, tin cans, water bottles, aluminum wrappers, etc. Electrical tape is useful. Solder, bright LEDs, dim charging indicator LEDs, diodes, resistors, extra cable, rechargeable batteries, switches, battery holders, 3-4V solar panels such as http://www.siliconsolar.com/oem-solar-panels-p-500965.html (or students can design their own panel and holding case for unenclosed or unsoldered cells)

Multimeters

paper for student design work?

Ideally 1-2 students per lamp, and 1 teaching assistant per 5 groups. Students may need help soldering, and figuring out the circuitry. Alternatively, the class can break into two groups for lamp construction, and charging.

Why should students want to participate in this lesson?

Take home your very own lamp! Make a useful battery charger! The latter will be particularly exciting if chargers can be adapted for cell phone batteries…

Why should teachers want to teach it?

Teach photovoltaics and solar energy, as well as design and electronics skills.

If this lesson (and its prerequisites) were the only PEN lessons someone took, what should they be able to do?

Build a mini charging circuit for a solar panel. Make an effective LED lamp.

If you had to teach this lesson tomorrow morning, what would you spend tonight working on? (assuming that materials were not an issue)

How to best explain photovoltaics, as well as circuitry elements. How to encourage students to use local materials for building a lamp.

If you hadn’t taught this lesson before, what questions would you have for someone who had taught a very similar lesson?

How durable were students' lamps? How did you explain photovoltaics without oversimplifying the science?

If the only materials available were broken radios, TVs, and computers, could you do all the electronics in this lesson? (assuming you had solder, soldering irons, etc.) If not, what would be missing?

Possibly, although you'd need a good rechargeable battery.

If the only structural materials available were dish-cloths, cardboard, and plastic bags, could you make the mechanical bits of this lesson? (assume equipment as above) If not, what would be missing?

If you could find some more structural junk, yes.