1. Hands-on Energy and Climate Projects in Schools Chris Waltham UBC Physics & Astronomy 2015.10.23

2. A large fraction of the energy we use is in the form of electricity; this has to be made from some other form of energy: Fossil fuels (burn)→ Heat (boiler) → Kinetic energy (turbine) → Electricity (generator) Biomass (burn)→ Heat (boiler) → Kinetic energy (turbine) → Electricity (generator) Hydro (solar/rain)→ Potential energy (dam) → Kinetic energy (turbine) → Electricity Wind (air flow) → Kinetic energy (turbine) → Electricity (generator) Solar (light) → Electricity (photovoltaics) Waves (solar/wind)→ Potential/kinetic energy (waves) → Kinetic energy (turbine) → Electricity (generator) At each step energy is “lost” to heat Background: Electricity Generation

3. Revisit: energy definition and foundation of SI units

4. Circumference of circle 20 cm Period of revolution 2 s Force 1 N (9.81 kg weight) Mechanical Power = 0.2 W = 100 mW Voltage reading = 0.5 V Current reading = 100 mA Electrical Power (heats load resistor) = 50 mW Electrical conversion efficiency = 50 mW / 100 mW = 50% Tactile! Feel what a newton is like, what 100 mW of output is like Activity: Hand Crank Exercise Using the geared motor as a generator and the supercapacitor for storage, students can feel the resistance to turning the generator when the supercap is connected into the circuit.

5. Background: Wind Turbines for Energy Sun → Heat → Linear kinetic energy of air → Rotational kinetic energy of blades/turbine → Electrical energy How? Factors that affect amount of power generated

6. Activity: Constructing a Wind Turbine Similarly, water...? Measure electrical output (simple voltage reading at lower grade levels) Optimize blade configuration: possible at all grade levels Optimize gear configuration (higher grade levels) Optimize load (higher grade levels)

7. Hotter things radiate at smaller wavelengths, and vice versa At 6000 K (e.g. the Sun’s surface), the peak power wavelength is 500 nm, middle of the visible range (green) At 300 K (e.g. the Earth, us), the peak power wavelength is 10 μm, in the thermal infrared i.e. 20 x the temperature, the peak power wavelength goes down by a factor 20 Background: Electromagnetic radiation Anything with a non-zero temperature radiates electromagnetic energy with a broad spectrum

8. An infrared thermometer works by measuring the intensity of emitted thermal infrared Activity: Playing with Infrared Thermometers Asphalt Grass Wet things Trees Car windows The sky Exterior of buildings Low-e glass Environmental Measurements Most dramatic variations on clear-sky days/nights Learn how to collect data and produce a map

9. Background: The Greenhouse Effect http://barrettbellamyclimate.com/page15.htm Radiation from Sun and Earth msemac.redwoods.edu What gets through our atmosphere

10. Activity: Measuring Passive Solar Heating Use probe thermometers Observe the temperature of small cubes of various colours and transparency exposed to direct sunlight Need to take some care with experimental design Watch the sky Plot data as a function of time

11. Light → Electricity Optimize power generated by photocell Compare indoor and outdoor lighting levels Activity: Photovoltaics and Lighting Electricity → Light Use kill-a-watt meter to show power requirements of various (household) light bulbs Use hand-crank activity to estimate comparative efficiencies of small low-voltage light bulbs Light → Electricity → Light Use photocell to light a small bulb Note efficiency (qualitatively)