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Course 247 · Life course 69

Measure and Reduce Household Energy Use

A desk-based household energy comparison with checked kWh estimates, usage assumptions and a safe no-installation conservation recommendation. Six introductory lessons use supplied practice cases.

Before you start

Use paper or a free text document; every core input is supplied in the lessons.

Practical Math and Data for Work and Training See everything you’ll need

Free download · Original practice data · No external account required. Download the starter pack

What you’ll leave with

A desk-based household energy comparison with checked kWh estimates, usage assumptions and a safe no-installation conservation recommendation.

Start course Start without an account. Sign in to save lesson progress across devices.

Your project

Start with the practice files. Build your project one lesson at a time.

Practice files are free without an account. Sign in to save your project record in My Proof: a description, checklist, and optional work link. Keep the original files in your own app or notebook; saving a project record does not upload them.

  1. Get your materialsDownload practice filesSupplied practice cases, a blank working record, complete lesson instructions, and annotated worked examples.
  2. Make your projectView the project checklist Work in your own notebook, document, or software. Use the supplied practice examples when you prefer.
  3. Keep a private recordSave a project record Sign in to save a description and checklist, then return to update them.
Course handbook

Know the route before you begin.

Here’s what you’ll need and what you’ll make. You can return to this guide during any lesson.

Who this is for

Learners aged 14+ building subject foundations and practical independence. Adults can use the same supplied cases.

Prepare before lesson one
  • Use paper or a free text document; every core input is supplied in the lessons.
  • A basic calculator is optional; show the method, units and checks.
  • Suggested earlier course: Practical Math and Data for Work and Training
Your final project

Finish with proof you can use.

A desk-based household energy comparison with checked kWh estimates, usage assumptions and a safe no-installation conservation recommendation.

Save a project record in My Proof
See project checklist and review criteria

Keep your working files in your own notebook or software. Save a private description, checklist, and work link in My Proof.

What to include

  • Calculate power-time energy with explicit units.
  • Complete a quantity-aware 30-day device table.
  • Separate ratings, measurements and standardized estimates.
  • Compare matched lighting output and calculate differences.
  • Recommend an existing-control action preserving essential services.
  • Recalculate the final comparison and retain evidence limits.

Review and revise

Use these criteria to check your work and choose what to improve.

  • Method: applies the course-specific rules to the supplied cases with visible intermediate work.
  • Accuracy: results agree with the stated facts, units, boundaries and independent checks.
  • Reasoning: explains why the result follows and identifies a limitation or unresolved question.
  • Transfer: completes changed cases and revises the final project when a relevant assumption changes.
Three ideas to help you along the way
Three useful ideas

The rules behind the steps.

01

Check the specific conditions

Power is the rate of energy transfer; watts describe power. Energy accumulates over time: for constant power, watt-hours equal watts times hours. One kilowatt is 1,000 watts, and one kilowatt-hour is 1,000 watt-hours. A high-power device used briefly can consume less energy than a lower-power device used for many hours.

02

Follow the supplied evidence

For a constant-power estimate, kWh=(watts÷1,000)×hours per day×days. Include quantity when more than one identical device runs. Convert minutes to hours by dividing by 60. Name the period; daily and monthly totals cannot be compared as if they covered the same time.

03

Keep the limits visible

A conservation recommendation should preserve essential services and use actions within the person’s responsibility. Turning off an unused ordinary light can reduce runtime without equipment modification. Do not unplug essential medical devices, disable alarms, change equipment wiring, open appliances or compromise necessary temperature conditions to chase a number.

What do these words mean?
Key words

Key terms worth knowing.

Power
A rate of energy transfer, expressed here in watts.
Watt-hour
Energy corresponding to one watt used for one hour.
Kilowatt-hour
One thousand watt-hours of energy.
Lumens
A unit describing light output rather than electrical power.
Active time
The interval during which the stated operating power applies.
Equal service
A comparison holding the useful task and required output comparable.
Your route

6 lessons.
One useful project.

Work in order the first time. Each lesson makes something the next lesson can use.

  1. 1
    Up next

    Distinguish power from energy

    Distinguish a power rating from an energy quantity and combine power with duration.

  2. 2
    10 min

    Calculate use over a stated period

    Estimate period energy with time conversion, device quantity and a consistent boundary.

  3. 3
    9 min

    Separate measurements, ratings and estimates

    Choose an appropriate energy estimate from evidence type and active operating time.

  4. 4
    9 min

    Compare options that provide the same service

    Compare lighting energy after matching output, duration and suitability assumptions.

  5. 5
    9 min

    Prioritize safe conservation choices

    Screen conservation options for essential-service, safety and responsibility constraints.

  6. 6
    13 min

    Check and revise the final energy comparison

    Revise matched energy estimates and propagate the change into the final comparison.

Use the tools

Tools to help you practice.

See all tools
ZIP · practice files

Measure and Reduce Household Energy Use practice files

Supplied practice cases, a blank working record, complete lesson instructions, and annotated worked examples.

Text worksheet

Your course project worksheet

A downloadable text worksheet with each lesson’s working output, space for your answers, and the shared final-project checklist. Save your own copy.

Source transparency

Sources and further study.

Explore the references behind the lessons and take your learning further. Source notes explain access and reuse.

Virginia Cooperative Extension: power-time energy estimation
Source & access notes · checked 2026-10-01

Web open/search showed the official page, its topic heading and relevant concept description. This is a content/source check, not a provider endorsement.

Access: Official page retrieved with the web reader on 2026-10-01; interactive tools and videos were not certified by retrieval.

Reuse: Original fictional teaching cases, calculations, questions and examples; link and short factual paraphrase only. No copied source exercises or illustrations.

FTC: standardized EnergyGuide estimates
Source & access notes · checked 2026-10-01

Web open/search showed the official page, its topic heading and relevant concept description. This is a content/source check, not a provider endorsement.

Access: Official page retrieved with the web reader on 2026-10-01; interactive tools and videos were not certified by retrieval.

Reuse: Original fictional teaching cases, calculations, questions and examples; link and short factual paraphrase only. No copied source exercises or illustrations.

U.S. Department of Energy: lumens and lighting energy
Source & access notes · checked 2026-10-01

Web open/search showed the official page, its topic heading and relevant concept description. This is a content/source check, not a provider endorsement.

Access: Official page retrieved with the web reader on 2026-10-01; interactive tools and videos were not certified by retrieval.

Reuse: Original fictional teaching cases, calculations, questions and examples; link and short factual paraphrase only. No copied source exercises or illustrations.

U.S. Department of Energy: household conservation actions
Source & access notes · checked 2026-10-01

Web open/search showed the official page, its topic heading and relevant concept description. This is a content/source check, not a provider endorsement.

Access: Official page retrieved with the web reader on 2026-10-01; interactive tools and videos were not certified by retrieval.

Reuse: Original fictional teaching cases, calculations, questions and examples; link and short factual paraphrase only. No copied source exercises or illustrations.

Ready when you are

Start with the first useful move.

You’ll always know what to do, what to make, and where to go next.

Start lesson one