What is Energy?
What is Energy
Energy is in everything. It is neither lost nor destroyed. We use energy for everything we do, from making a jump shot to baking cookies to sending astronauts into space and even sleeping. Energy comes in forms and sources. Two forms of energy: “Stored” or potential energy and “working” or kinetic energy. For example, the food you eat contains chemical energy and you body stores this energy until you use it when you work or play. Other forms of energy include: Thermal (heat)
Radiant (light)
Sound
Electrical
Chemical
Nuclear
What are Sources of Energy? Ask your students to compare their state’s fuel mix against several other states in the U.S. What differences do they see? Why do they think that there is so much difference state-to-state?
The chart below shows the 2018 average breakdown of US energy consumption, by source.
You will note that the bulk of the energy consumed in the US comes from nonrenewable sources (coal, petroleum [oil], and natural gas). Electric generation fuel mixes vary from state to state and region to region, depending upon the availability and cost of fuels located there. You can use the national average, but to really give a perspective on the differences in electricity generation state-by-state, it’s a good idea to enter your state-specific data by clicking here:
https://www.eia.gov/beta/states/states/ut/overview Links to an external site.
Try looking up other surrounding states to see how they compare to Utah.
- How to Save Energy a. What is the difference between energy efficiency and energy conservation?
- Energy Efficiency refers to the amount of work you get out of a device compared to the amount of energy put into the device – the less energy a device uses to get X amount of work, the more efficient it is.
- Energy Conservation is essentially, not using energy: turning off your computer and monitor when not working with it saves energy, for example. Of course, building devices that do the same work with less energy [more efficient] saves energy. So in that way the two concepts are related.
iii. Ways to Conserve Energy:
- When your cell phone is done charging unplug the charger from the wall
- Change to CFLs, Compact Florescent Light bulbs
- Use products with Energy Star labels
- Don’t leave water running when you’re not using it
- Turn off lights, fans, and electronics when you’re not in the room
- Kill A Watt Device
- What is a Watt?
- A metric unit of power, used in electric measurements, to give the rate at
which energy is used.
- Explain that 1,000 watts = 1 kilowatt
iii. Show pictures of the electric devices you will be testing and have
students guess how many watts each device uses.
- What is this device used for?
- It is used to act as a meter going between the item that draws the power
and the power source.
- How to use the Kill A Watt
How to use a kill a watt meter
Links to an external site.
- Plug the Kill a Watt into a wall socket.
iii. Insert the plug for the electric device you want to test and turn the
electric device on.
- Press the grey Watt button and record in your table the power reading.
- Repeat this process for when the device is turned off.
Measuring Electricity usage
- Converting Watts to Kilowatts and cost per year
Electricity is measured in kilowatt-hours (kWh)
1 kilowatt = 1000 watts KWh = kilowatts x hours the appliance is on
To get kilowatt-hours, take the wattage of the device, multiply by the number of hours you use it, and divide by 1000. (Dividing by 1000 changes it from watt-hours to kilowatt-hours.)
- Electricity Cost – the cost of electricity depends on where you live, how much you use, and possible when you use it. The electric company measures how much electricity you use in kilowatt-hours (kWh). Your bill might have multiple charges per kWh and you have to add them all up to get the total cost per kWh.
Electricity rates vary widely. Prices are usually highest for residential and commercial consumers because it costs more to distribute electricity to them. Industrial consumers also use more and can take their electricity at higher voltages so it does not need to be stepped down. These factors make the price of power to industrial consumers closer to the wholesale price of electricity. The cost to generate electricity actually changes minute-by-minute. However, most consumers pay rates based on the seasonal cost of electricity. Changes in prices generally reflect variations in electricity demand, availability of different generation sources, fuel costs and plant availability. Prices are usually highest in the summer because more expensive generation is added to meet the higher demand.
Use this website to check the electricity rates in Utah:
Student worksheet