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Engineering challenge: an energy-efficient classroom

The school pays a large electricity bill. Plan lighting, windows and equipment so a classroom uses less energy and saves money.

− 85 % energy
LevelS2 to S6 · teams of 3–4
Time2 lessons or a weekend project
SubjectsPhysics, Mathematics and more
PriceFree: no account

🎯 Aim

To calculate electrical energy and cost (E = Pt), compare lamps, use daylight, and work out the payback time of an energy-saving change.

You will learn to

  • Calculate energy in kWh and its cost.
  • Compare filament, CFL and LED lamps.
  • Explain the role of daylight.
  • Calculate a payback time.

🧭 What to do

  1. Step 1: choose the type and number of lamps.
  2. Work through each numbered step: move the sliders and choose the options.
  3. Watch the drawing and the results change after every choice.
  4. Compare the options and their costs in the table and the chart.
  5. Answer the questions below, using 💡 Hint before the method.
  6. Justify your design in the last step, then download your design report.

🛠️ Design workbench

🧠 Investigate: answer from your design

Type your answer and tap Check. Use 💡 Hint first; open the method only when you are stuck.

📄 My design report

Your report collects the aim, your design, the graphs, your answers and your conclusion. It is made on your phone or computer: nothing is sent to anyone.

Check your conclusion

Lighting energy = power × time. LED lamps use about 85 % less energy than filament bulbs for the same light, and windows of about 20 % of the floor area remove the need for lamps in the day. Changing 8 bulbs to LED pays for itself in about 3 months.

➕ Get more from this challenge

📝 Free

Print the worksheet (button above), download the data, and save your report. Teachers can project this page in class.

📦 Premium Lab Pack

1 000 RWF

  • Team workbook for every design step
  • Data and price list template
  • Presentation and assessment rubric
  • Teacher guide with a full model answer

👩‍🏫 For teachers

Use it as a practical when apparatus is missing, as homework, or as a project. Free lesson plans help you plan, teach and assess.

🔗 Related in the subjects

DONAT STEM Interactive Labs · original work by BIZIYAREMYE Donat · data are realistic models for learning · free forever