Energy Curriculum notes


    VOM meter: 2 lead VOM, e.g. Fluke Model 114

    Measure ohms short and open

    Measure ohms across chest (can calculate fatal voltage here if current is known)

    Measure ohms around circle of students, break circuit (circuit concept here: need two wires)

    Define "circuit"

    Measure voltage across chest-why does it vary? (EKG concept, can extend to differential EKG)

    Measure DC voltage of small batteries (learn what symbols for DC and AC voltage are on the meter)

    Measure AC voltage at outlet (caution here)

    Explain why dry hands are better, cross body shocks, grounding

    Measure resistance from hands to ground

    Electrical safety unit…

    Kill-a-Watt unit

    Ohmic loads: tea maker, coffee maker (make sure water is cool)


    P = I2R

    Measure voltage at outlet

    Measure resistance of ohmic load with VOM

    Predict power used, current

    Measure power, current (ohmic load)

    Power measured/power calculated = ?

    Repeat with vacuum cleaner or other motor device

    Recalculate power calculated vs. measured

    P = VI again, vs. power measured

    Try the P.F. button

    Light bulb analysis:

    Incandescent bulb: measure R with VOM, measure power with KaW unit

    CFL: repeat

    LED: repeat

    Next measure light output for each, compare with power used (measured with KaW unit)

    Cost to run:

    Calculate cost to use each bulb for 1 hour, define kWh.

    Calculate cost to run tea maker for 1 hour, define kWh.

    Calculate savings between LED, CFL and incandescent bulb, per day, week, month, year, over lifetime

    Define ROI and TCO

    Renewable energy:

    ROI and TCO

    PV, Wind and Solar thermal

    ROI is time to pay off device (in days, months or years)

    TCO is total cost of ownership (should be negative)

    Data from websites or hands-on if available

    Efficiency evaluation

    PV panel

    Measure incident solar radiation (or from weather service) in W/m2

    Measure output of PV panel, using ohmic load (resistor or tea maker), current, voltage

    Calculate % efficiency

    Solar Thermal Panel

    Solar thermal same incident solar, measure temp in and out for solar panel, and time to fill 1 liter container (flux)

    Use mc∆t to calculate calories captured/harvested, 4.18j = 1 calorie, j/s = Watts

    Wind turbine

    Difficult with varying wind, you may be able to hold small turbines while driving a truck (this is how some are actually evaluated)

    Area of turbine is needed, and wind speed, altitude (air density) as well

    Look up Betz coefficient, 0.39 is max (why?)

    May be done using data from manufacturers

    Residential energy audits

    TED units (theenergydetective.com)

    Installed at houses, classrooms

    Measures predicted billing, uses, trends

    Excellent for articulating with commercial energy audits

    Control by web units, using current transformers

    CBW analog units process 8 analog 0-5Vdc inputs to web interface with logging

    CTs are Hawkeye 922 units (0-5 Vdc output), with 30,60 and 120 Ampere rating

    Larger ones as well

    Assume PF = 1.00, calculate Watts from P = VI (assume voltage constant, but measure accurately to calibrate)

    Energy Lab server


    Telemetry of campus or remote locations

    Can interface with CBW units globally, as long as they have access to internet

    Used in "energy hunts" finding lights or loads hidden around buildings