1 / 25

Electrical Efficiency

Electrical Efficiency LG: to understand how energy efficiency is calculated & use it to determine energy efficiency of household electrical devices. Electrical Efficiency Electrical Power: the rate at which electrical energy is produced or used. -measured in Watts (W)

carolyn-ray
Download Presentation

Electrical Efficiency

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Electrical Efficiency LG: to understand how energy efficiency is calculated & use it to determine energy efficiency of household electrical devices

  2. Electrical Efficiency Electrical Power: the rate at which electrical energy is produced or used. -measured in Watts (W) -one Watt is equal to one Joule of energy used per second LG: to understand how energy efficiency is calculated & use it to determine energy efficiency of household electrical devices

  3. Electrical Efficiency Electrical Power: the rate at which electrical energy is produced or used. -measured in Watts (W) -one Watt is equal to one joule of energy used per second e.g. 100 W light bulb uses four times as much energy per second as a 25 W bulb. LG: to understand how energy efficiency is calculated & use it to determine energy efficiency of household electrical devices

  4. Electrical Efficiency kilowatt-hour (kWh): the SI unit for measuring electrical energy usage -1 kWh is the use of one killowatt of energy for one hour -3600 times as much energy as 1 Joule LG: to understand how energy efficiency is calculated & use it to determine energy efficiency of household electrical devices

  5. Electrical Efficiency LG: to understand how energy efficiency is calculated & use it to determine energy efficiency of household electrical devices

  6. Electrical Efficiency Efficiency: comparison of the energy output of a device with the energy supplied e.g. Clothes dryers -older clothes dryer uses 800 kWh per year -new clothes dryer uses 300 kWh per year -they both do the same job so the new dryer is more than twice as efficient LG: to understand how energy efficiency is calculated & use it to determine energy efficiency of household electrical devices

  7. Electrical Efficiency Calculating efficiency of a Device: percent efficiency = energy in x 100% energy out LG: to understand how energy efficiency is calculated & use it to determine energy efficiency of household electrical devices

  8. Electrical Efficiency Calculating efficiency of a Device: percent efficiency = energy in x 100% energy out short form: LG: to understand how energy efficiency is calculated & use it to determine energy efficiency of household electrical devices

  9. Electrical Efficiency Example: A light bulb uses 100 J of energy and produces 35 J of light energy. Calculate the energy efficiency of the light bulb. LG: to understand how energy efficiency is calculated & use it to determine energy efficiency of household electrical devices

  10. Electrical Efficiency Example: A light bulb uses 100 J of energy and produces 35 J of light energy. Calculate the energy efficiency of the light bulb. Given: Eout = 35 J Ein = 100 J Unknown: % efficiency LG: to understand how energy efficiency is calculated & use it to determine energy efficiency of household electrical devices

  11. Electrical Efficiency Example: A light bulb uses 100 J of energy and produces 35 J of light energy. Calculate the energy efficiency of the light bulb. Given: Eout = 35 J Ein = 100 J Unknown: % efficiency Ein Select: % efficiency = _____ x 100% Eout LG: to understand how energy efficiency is calculated & use it to determine energy efficiency of household electrical devices

  12. Electrical Efficiency Example: A light bulb uses 100 J of energy and produces 35 J of light energy. Calculate the energy efficiency of the light bulb. Ein Select: % efficiency = _____ x 100% Eout Solve: % efficiency = 100 J x 100% 35 J =35% LG: to understand how energy efficiency is calculated & use it to determine energy efficiency of household electrical devices

  13. Electrical Efficiency Try this: A toaster oven uses 1200 J of energy to produce 850 J of thermal energy. Calculate the efficiency of the toaster oven. LG: to understand how energy efficiency is calculated & use it to determine energy efficiency of household electrical devices

  14. Electrical Efficiency Try this: A toaster oven uses 1200 J of energy to produce 850 J of thermal energy. Calculate the efficiency of the toaster oven. Given: Eout = 850 J Ein = 1200 J Unknown: % efficiency Select: Ein % efficiency = _____ x 100% Eout LG: to understand how energy efficiency is calculated & use it to determine energy efficiency of household electrical devices

  15. Electrical Efficiency Try this: A toaster oven uses 1200 J of energy to produce 850 J of thermal energy. Calculate the efficiency of the toaster oven. Solve: % efficiency = 850 J x 100% 1200 J = 71% therefor the toaster oven is 71% efficient LG: to understand how energy efficiency is calculated & use it to determine energy efficiency of household electrical devices

  16. Electrical Efficiency Cost of Operating Electrical Devices: LG: to understand how energy efficiency is calculated & use it to determine energy efficiency of household electrical devices

  17. Electrical Efficiency Example: a laptop computer uses a 75 W adapter when it is plugged in. Electricity costs 5.6¢/kWh. Calculate how much it would cost to operate the laptop for 1 year for 24 hours per day. LG: to understand how energy efficiency is calculated & use it to determine energy efficiency of household electrical devices

  18. Electrical Efficiency Example: a laptop computer uses a 75 W adapter when it is plugged in. Electricity costs 5.6¢/kWh. Calculate how much it would cost to operate the laptop for 1 year for 24 hours per day. Given: power = 75 W = 0.075 kW LG: to understand how energy efficiency is calculated & use it to determine energy efficiency of household electrical devices

  19. Electrical Efficiency Example: a laptop computer uses a 75 W adapter when it is plugged in. Electricity costs 5.6¢/kWh. Calculate how much it would cost to operate the laptop for 1 year for 24 hours per day. Given: power = 75 W = 0.075 kW time = 24 hours per day for 365 days = 8760 hours cost = 5.6¢/kWh LG: to understand how energy efficiency is calculated & use it to determine energy efficiency of household electrical devices

  20. Electrical Efficiency Example: a laptop computer uses a 75 W adapter when it is plugged in. Electricity costs 5.6¢/kWh. Calculate how much it would cost to operate the laptop for 1 year for 24 hours per day. Unknown: cost to operate Select: cost to operate = power x time x cost of used electricity LG: to understand how energy efficiency is calculated & use it to determine energy efficiency of household electrical devices

  21. Electrical Efficiency Example: a laptop computer uses a 75 W adapter when it is plugged in. Electricity costs 5.6¢/kWh. Calculate how much it would cost to operate the laptop for 1 year for 24 hours per day. Unknown: cost to operate Select: cost to operate = power x time x cost of used electricity Solve: cost to operate = 0.075 x 8760 x 5.6 = 3679¢ ($36.79) LG: to understand how energy efficiency is calculated & use it to determine energy efficiency of household electrical devices

  22. Electrical Efficiency Example: a laptop computer uses a 75 W adapter when it is plugged in. Electricity costs 5.6¢/kWh. Calculate how much it would cost to operate the laptop for 1 year for 24 hours per day. Unknown: cost to operate Select: cost to operate = power x time x cost of used electricity Solve: cost to operate = 0.075 x 8760 x 5.6 = 3679¢ ($36.79) LG: to understand how energy efficiency is calculated & use it to determine energy efficiency of household electrical devices

  23. Electrical Efficiency Try this: Calculate the cost of operating a 1500W hair dryer to dry your hair for 6 minutes per day for 3 days. The cost of electricity is 5.6¢/kWh LG: to understand how energy efficiency is calculated & use it to determine energy efficiency of household electrical devices

  24. Electrical Efficiency Try this: Calculate the cost of operating a 1500W hair dryer to dry your hair for 6 minutes per day for 3 days. The cost of electricity is 5.6¢/kWh Given: power = 1500 W = 1.500 kW time = 6 minutes per day for 3 days = 6 min x 3 = 18 min = 0.30 hours cost = 5.6¢/kWh Unknown: cost to operate LG: to understand how energy efficiency is calculated & use it to determine energy efficiency of household electrical devices

  25. Electrical Efficiency Try this: Calculate the cost of operating a 1500W hair dryer to dry your hair for 6 minutes per day for 3 days. The cost of electricity is 5.6¢/kWh Select: cost to operate = power x time x cost of used electricity Solve: cost to operate = 1.500 x 0.30 x 5.6 = 2.52¢ LG: to understand how energy efficiency is calculated & use it to determine energy efficiency of household electrical devices

More Related