Question

There are many ways energy conservation can reduce a country's energy use per capita. The table below shows conversion factors for different types of renewable and non-renewable energy. Use the table to answer the questions:

Conversion Factors
1 kWh (kilowatt-hour) 3,412 Btu
U.S Average Utility Rate $0.12/kWh


1) Using green design features is one way of addressing energy conservation. This includes using energy efficient appliances. Calculate the kilowatt-hour of energy used per year by an average 255-watt washing machine, used three hours a day.

2) Calculate the amount of energy and money saved by using a more efficient 180-watt washing machine instead of a 255-watt washing machine. Based on energy savings, provide reasoning for using more green design features in homes.

3) Describe two methods for conserving energy around a home that could reduce energy use per capita for a household.

Answer 1

The energy used by a 255-watt washing machine when used for three hours a day can be calculated as follows:

Power = 255 watts

Time = 3 hours/day = 1095 hours/year (assuming 365 days in a year)

Energy used = Power x Time = 255 x 1095 = 279,225 watt-hours

To convert watt-hours to kilowatt-hours, we divide by 1000:

279,225 / 1000 = 279.225 kWh per year

Therefore, the washing machine uses approximately 279.225 kWh of energy per year.

The difference in power consumption between the 180-watt washing machine and the 255-watt washing machine is 75 watts. If we assume the washing machine is used for three hours a day, the energy savings per day would be:

Energy saved per day = (255 - 180) x 3 = 225 watt-hours

To convert watt-hours to kilowatt-hours, we divide by 1000:

225 / 1000 = 0.225 kWh per day

To calculate the energy and cost savings per year, we multiply by 365 days and the average utility rate of $0.12/kWh:

Energy savings per year = 0.225 x 365 = 82.125 kWh per year

Cost savings per year = 82.125 x $0.12 = $9.86 per year

Using more energy-efficient appliances and implementing green design features in homes can lead to significant energy and cost savings over time. This can also reduce the overall demand for energy, which can help to reduce greenhouse gas emissions and mitigate climate change.

Two methods for conserving energy around a home include:

Installing programmable thermostats: Programmable thermostats allow homeowners to set different temperatures for different times of the day, which can help to reduce energy use for heating and cooling. For example, homeowners can set the thermostat to lower the temperature during the day when they are at work or school, and then have it automatically adjust to a more comfortable temperature when they return home.

Using energy-efficient lighting: Replacing traditional incandescent light bulbs with energy-efficient LED bulbs can help to reduce energy use for lighting. LED bulbs use less energy and last longer than traditional bulbs, which can also lead to cost savings over time. Additionally, turning off lights when they are not needed can further reduce energy use.

Step-by-step explanation: