APES Energy Unit

Refrigerator AA uses 500 watts per hour when the motor is operating. The motor needs to run an average of 12 hours per day, every day, to stay at a constant, cold temperature. This model of refrigerator lasts an average of 20 years before it needs to be replaced and costs $1,000. Each kWhkWh of electricity costs $0.12. The homeowner is considering purchasing a new model of refrigerator, Refrigerator BB. This model uses 50 percent less energy per year. Which of the following would be the estimated cost savings for the homeowner in a year if she replaces Refrigerator AA with Refrigerator BB?

$131.40

Natural gas is often priced in units of dollars per therm. One therm equals 100,000100,000 BTUsBTUs. A certain family uses 600600 therms of energy to heat its home annually using a natural gas furnace that is 8080 percent efficient. The family is considering replacing its current furnace with one that is 9696 percent efficient. Assuming the cost of a therm is $0.30$0.30, which of the following would be the family's annual savings in the cost of home heating?

$28.80

In many parts of the United States, homeowners use a significant portion of their energy budget to heat their home in the winter. It has been determined that lowering a thermostat by 3°F3°F in the winter can reduce the energy costs by about 1010 percent in many homes. An individual homeowner lowers their thermostat by 33 degrees exactly halfway through the billing period. For the month that the thermostat was lowered, the heating bill was $95$95. How much money did the family save in the month in which they lowered the thermostat setting halfway through the billing period?

$5.00

Solar energy systems have been increasing the percentage of energy they contributed to the global energy supply. One of the fastest growing types of solar energy systems uses photovoltaic (PV)(PV) cells. The graph below shows the solar power generated in one day in a country in the Northern Hemisphere in the month of July. Which of the following time periods has the highest energy output?

12 pm-2 pm

A family of four lives in a three-bedroom house and uses an average of 900kWh of electricity per month. The family cools their house for three months during the summer with two window-unit air conditioners that each use 350kWh of electricity per month. Which of the following is the percentage of the family's total annual electricity that is used to run the two air conditioners for the three summer months?

19.4%

Refrigerator AA uses 500 watts per hour when the motor is operating. The motor needs to run an average of 12 hours per day, every day, to stay at a constant, cold temperature. This model of refrigerator lasts an average of 20 years before it needs to be replaced and costs $1,000. Each kWhkWh of electricity costs $0.12. How many kilowatt hours (kWhkWh) per year does refrigerator AA use?

2,190kWh

Based on the data above, approximately how much greater is the average cost of electricity produced in the United States from offshore wind than from hydroelectric power?

2.3 times greater

Which of the following is the approximate projected rate of change in renewable energy consumption from 2010-2040 ?

2.33 quadrillion BTUs per year

A state is looking to reduce the cost of transportation, which uses 7.10×10^14 BTUs per year. Currently the cost of 106106 BTUsBTUs is $20.00. How much will the state save in one year if they implement regulations requiring all transportation methods to be 20% more efficient.

2.84×10^9dollars

How many BTUsBTUs were consumed in the United States in 2017 by consumers that used petroleum as a fuel source?

36 quadrillion BTUs

An individual has been driving a passenger vehicle to work, averaging 6060 miles a week in a car that averages 2222 miles per gallon. The individual plans to purchase a hybrid vehicle that averages 5050 miles per gallon. If the individual drives to work 5050 weeks a year, how much gas will they save if they switch to a hybrid vehicle for their commute?

76 gallons

Which of the structures in the diagram is the site where the nuclear power plant accidents at Three Mile Island and Chernobyl occurred?

A (Control Rods)

Which of the following best describes a potential negative environmental effect of fossil fuel extraction?

Air pollutants, such as methane and particulate matter, are emitted into the atmosphere.

Which of the following identifies the air pollutants most commonly released during the burning of biomass?

Carbon dioxide ( CO2CO2 ), particulate matter ( PMPM ), and carbon monoxide ( COCO )

Which of the following describes an environmental problem that can result from the combustion of fossil fuels to generate electricity?

Carbon dioxide is a product of the combustion fossil fuels, and it can lead to global climate change when released into the atmosphere.

In an apartment building, exhaust from a gas-powered electrical generator is captured to produce hot water to heat a swimming pool. Which of the following is illustrated by this process?

Cogeneration

Which of the following best describes the total consumption of all fossil fuels in 2040 compared to the consumption of nuclear energy in 2040?

Consumption of fossil fuels will be approximately 13 times greater than consumption of nuclear energy.

After the Industrial Revolution, the use of fossil fuels increased significantly. Despite the documented environmental effects of these resources and the availability of renewable resources, the use of nonrenewable sources continues. Which of the following statements best explains why there is continued widespread use of nonrenewable fossil fuels in energy production in the United States?

Established technology and transportation infrastructure for fossil fuels allows these resources to be converted into energy to meet consumer demand.

Which of the following describes a step in the generation of electricity using fossil fuels that can most directly lead to an environmental problem?

Fossil fuel is burned to boil water.

Which of the following best describes an environmental problem associated with hydrologic fracturing, or fracking?

Fracking fluids can escape from the drill hole and contaminate surface water and groundwater.

Which of the following best describes a potential advantage of using geothermal energy instead of solar farms for power generation?

Geothermal energy can be harnessed without destroying large tracts of habitat, whereas solar farms require large amounts of space.

Which of the following best describes a disadvantage of geothermal energy production?

Geothermal energy implementation in homes and businesses has a high upfront cost, and electricity is needed to operate pumps.

Geothermal energy is used to run large and complex power stations as well as small and relatively simple pumping systems. Which of the following most accurately explains how geothermal energy is produced and utilized in these applications?

Geothermal energy uses the natural insulating power of Earth to create temperature differentials that are used to heat buildings in the winter and cool them in the summer.

Which of the following is required to convert geothermal energy into electricity?

Groundwater

Which of the following is a disadvantage of using hydrogen fuel cells?

Hydrogen gas is not readily available on Earth.

Which of the following best explains energy transformation in hydrogen fuel cells?

Hydrogen reacts with oxygen to produce water, which releases energy.

Throughout the world, especially the less-developed countries, burning wood or other biomass for heating or cooking in homes is common. One negative environmental impact of this practice is the production of particulates indoors, which can be a health hazard to humans. Which of the following describes the best strategy for mitigating this potential problem?

Installing effective ventilation systems in dwellings

Wind energy is increasingly relied upon to help meet global energy needs. Wind energy can be used to generate electricity using wind turbines. Which of the following correctly identifies the sequence of energy conversions that occur in a wind turbine?

Kinetic energy →→ mechanical energy →→ electrical energy

Natural gas, a nonrenewable fossil fuel, is often seen as an alternative fuel in the worldwide transition to a renewable energy future. Which of the following statements best explains why natural gas is often used as a fuel when countries are transitioning from nonrenewable to renewable energy sources?

Natural gas burns more efficiently and cleanly than other sources of carbon-based fossil fuels, thus contributing to a reduction in atmospheric carbon dioxide.

Which of the following PVPV panel systems is least effective at producing energy?

No tracking, tilted EAST

If peak electricity use occurs around 2p.m.2p.m. in the Los Angeles area and avoiding brownouts is more important to the installers of the PVPV panels than annual energy output, which of the following PVPV panel systems would be best to use in the area?

No tracking, tilted WEST

Which of the following is a characteristic of nonrenewable energy sources that distinguishes them from renewable energy sources?

Nonrenewable energy sources typically take a longer time to replenish than renewable energy sources do.

Which of the following best describes a benefit of increasing the number of offshore wind farms rather than onshore wind farms?

Offshore winds farms will produce up to three times as much electricity as wind farms on land because of increased wind speeds offshore.

Which of the following statements is best supported by the data shown in the graph?

PV panels that can track the Sun and are constantly moving to always directly face the Sun produce the most electricity daily and annually.

Which of the following best identifies a benefit of using renewable energy sources rather than nonrenewable energy sources?

Renewable energy sources are replenishable and are virtually inexhaustible by human consumption, whereas nonrenewable sources do not form in a short period of time.

Which of the following statements best describes a difference between nonrenewable and renewable energy sources?

Renewable energy sources can be replaced naturally at current consumption rates, whereas nonrenewable energy sources cannot be replaced easily.

Which of the following statements about the global distribution and use of fossil fuels is best supported by the data on the map?

Saudi Arabia and Australia produce large volumes of fossil fuels with relatively low energy demand.

Which of the following statements correctly explains the role of fossil fuels in the production of energy?

The combustion of fossil fuels heats water to produce steam, which then turns a turbine.

Which of the following best describes how the use of hydrogen fuel negatively impacts the environment?

The energy needed to produce the hydrogen fuel may come from fossil fuels, whose use contributes to ocean acidification and global climate change.

Which of the following statements about geothermal energy is accurate?

The location of geothermal energy sources ranges from short distances below ground to miles below the surface.

Which of the following statements correctly describes a difference between biomass-fired power plants and traditional fossil-fuel-burning power plants, such as coal-fired plants?

The operational costs of biomass plants are very high when compared with traditional fossil fuel plants.

Which of the following best describes the method of vehicle transport that is the most environmentally sustainable?

The use of a vehicle powered by hydrogen fuel cells because there are no carbon emissions

Which of the following is a drawback to using biofuels, such as ethanol, as a fuel source?

There is high energy investment in producing and processing the crops needed for ethanol production.

Which of the following is the most practical solution to maximizing energy production at wind farms while minimizing the risk to wildlife?

Turn off turbines during periods of maximum migration.

Which of the following would be most likely to be used as a fuel source for electricity generation in the plant displayed in the diagram?

Uranium-235

Solar energy systems have been increasing the percentage of energy they contributed to the global energy supply. One of the fastest growing types of solar energy systems uses photovoltaic (PV)(PV) cells. The graph below shows the solar power generated in one day in a country in the Northern Hemisphere in the month of July. Which of the following best describes how a homeowner using an off-the-grid PVPV solar system, in the same country as seen in the graph above, can power a home between 9:00 PM and 6:00 AM?

Using excess energy from a sunny day stored in batteries for power

Which of the following is an example of the process of cogeneration?

Using wastewater from electricity production for heating homes

Which of the following best describes an environmental problem that is often linked to the process of fracking?

Wastewater from fracking operations is injected into porous rock formations, which can induce seismic activity.

Which of the following gases is released from the structure labeled C in the diagram?

Water vapor

Wind energy is increasingly relied upon to help meet global energy needs. Wind energy can be used to generate electricity using wind turbines. Which of the following best describes electricity generation using wind turbines?

Wind turbines can be constructed on either vertical or horizontal axes.

Which of the following best describes why people in less developed countries use wood as a primary energy source?

Wood, in the form of firewood and charcoal, is often readily available.

Geothermal energy plants are a viable alternative energy source because they

use the heat from Earth's interior to create steam that is used to generate electricity and then can be pumped back into the ground

A hydrogen fuel cell-powered car driving on a highway is different from gasoline-powered cars because hydrogen fuel cell-powered cars only emit

water vapor and heat

Which of the following best explains the process of electricity generation in a hydrogen fuel cell?

At the anode, hydrogen is oxidized and electrons flow in a circuit to the cathode. At the cathode, oxygen reacts with the hydrogen to produce water. Water and heat are by-products of the reaction.

Wind energy is increasingly relied upon to help meet global energy needs. Wind energy can be used to generate electricity using wind turbines. Which of the following are often used for energy storage of wind power?

Batteries

Which of the following best describes an advantage of burning biomass rather than burning fossil fuels in developing countries?

Biomass production is cheaper than fossil fuel extraction, making it more readily available for use.

Which of the following is an environmental benefit associated with substituting ethanol for gasoline?

Burning ethanol produces fewer air pollutants than burning gasoline alone.

At which of the following locations in the nuclear power plant would an accident most likely result in the release of fission products?

C

In the diagram above, which letter correctly identifies the step where kinetic energy is converted to mechanical energy?

C

If a country possesses large oil and gas reserves within its borders, which of the labeled rock types must be present in the underlying geology of the country?

C Sedimentary Rock