Chapter 16
Which of the following is one of the three current major drawbacks of solar energy?
This resource is intermittent in nature.
Ogden and Sperling also discuss the challenges of using hydrogen as our major fuel. Identify the statement that is one of the challenges.
Time is needed to develop mechanisms to store hydrogen on vehicles.
Which of these statements is NOT true of wind power?
Wind turbines take up large amounts of land that is then unsuitable for other purposes.
Recently, how has Germany reduced its dependence on fossil fuels?
by utilizing the feed-in tariff system
A typical wind farm in the United States consists of __________.
many very large wind turbines clustered in a region with a low human population
Corn-produced ethanol ________.
results in higher food prices for corn and corn products
What happens to unused electricity generated by solar panels on a home? The extra electricity is __________.
sent back into the electrical grid for others to use
Which energy source's annual growth rate is about four times greater than that of tidal power?
solar
The first stage in generating power from a hydrogen fuel cell is to ________.
split hydrogen atoms into hydrogen ions (H+) and electrons
What is the ultimate source for geothermal energy?
the radioactive decay of elements deep within Earth
In contrast to Ogden and Sperling, Joseph Romm views hydrogen fuel-cell cars as an "environmental dead end." Which of the following statements from the pro-hydrogen essay would he dispute?
"Technologies that use hydrogen, notably fuel cells, are making rapid progress."
In what year did uranium oxide production peak in the United States?
1980
Based on the yearly average values, calculate one person's residential electricity needs for a year.
4,440 kWh per year
Approximately what percentage of overall U.S. energy consumption does bioenergy contribute?
5%
If efficiency of photovoltaic cells improves to 40%, how many square meters of photovoltaic cells would be needed for one person's yearly electricity use?
7.12 m2
If a home uses a large supply of solar panels to generate electricity, but has no battery system, surplus electricity that is produced is usually __________.
released into the power grid for others to use, generating a credit to the homeowner
The year 2030 goal set by the US Department of Energy is to generate __________.
20% of electricity using wind-powered systems
Assume that photovoltaic conversion of solar energy has 10% efficiency. Calculate how many square meters of photovoltaic cells would be needed to supply one person's electricity for the year, based on the yearly average values.
28.5 m2
What was the net amount of uranium imported into the United States in 2005?
45 million pounds
How much uranium oxide did the United States produce in 2005?
5 million pounds
Bagasse and sugar cane-based ethanol are major items in the energy resources of ________.
Brazil
Which projection has nonrenewables comprising roughly 50% of our energy production in 2050?
Projection 2
Use the information given by authors of both essays to select a strategy that achieves both short-term and long-term greenhouse gas emission reductions.
Invest in both hybrids and hydrogen fuel-cell research
Joan Ogden and Daniel Sperling view hydrogen as an ideal future fuel. Which of the following reasons do they discuss?
Several countries have committed billions of dollars in public funds to developing hydrogen energy.
How is cellulosic ethanol different from traditional corn-based ethanol?
It can be made from the nonfood portions of plants and from wood.
B20 represents ________.
a ratio of biodiesel to petrodiesel in alternative vehicular fuels
Of the following, ________ represent proper ranking of the U.S. total primary energy consumed from the greatest to least used.
fossil fuels, nuclear, bioenergy, hydroelectric, new renewables
Harnessing energy by designing buildings to maximize or minimize the absorption of incident solar radiation are ________.
passive solar energy collection
Ethanol produced from bioenergy starts with ________ produced by ________.
starch; corn and sugar cane
Which of the following is a challenge to using solar-generated electricity in places not connected to a power grid?
the lack of efficient and inexpensive battery technology
Ogden and Sperling argue that hydrogen is one of the only transportation fuels that can dramatically reduce greenhouse gas emissions. How might Romm respond to this statement?
No. Hydrogen cars are not a good use of renewable energy. We can achieve much greater greenhouse gas reductions by using renewable electricity to displace a future natural gas or coal power plant.
Based on the yearly average values, calculate the solar radiation per square meter for one year.
1,560 kWh per year
In the solar panel system presented in the video, which of the following was necessary to generate usable electrical current for a home?
DC power had to be converted to AC.
What is an example of an energy source that is renewable and has less environmental impact than fossil fuels?
bioenergy
Hydropower uses the __________ energy of water to generate electricity.
kinetic
Which of the following statements about ethanol is true?
Growing corn for ethanol requires substantial inputs of fossil fuel energy.
What is the basis for the use of hydrogen fuel cells?
It is extremely energy-efficient.
________ leads the world in percentage of its electricity derived from hydropower.
Norway
Which of the following best describes the energy conversion sequence in the solar panel system described in the video?
Photons carrying energy from the sun chemically react with silicon crystals to generate a flow of electrons.
Producing electricity using wind instead of fossil fuels __________.
generates no carbon dioxide in the process
The form of energy delivered to an electrical generating turbine in a geothermal facility is in the form of ________.
hot water or steam
The United States generates more electricity from ________ than from any other renewable energy source.
hydroelectric
Where would you most likely find a solar thermal power plant in the United States?
in the southwestern states
According to the data in Step 2, which source represents 32% of renewables?
none of them
More and more wind farms are being located ________ because winds are stronger there.
offshore
Designing buildings to maximize absorption of sunlight during winter and to keep the interiors cool during summer is referred to as ________.
passive solar energy collection
What is the process behind tidal energy?
the difference between high and low tides
What this figure does not tell you is ________.
the proportion of U.S. energy consumption that comes from non-renewable sources
If current trends continue, the United States is likely to
decrease domestic production and increase imports and exports.
Regarding PV cells, what is released from the "p-type" layer and transferred to the "n-type" layer, thus initiating an electrical current?
electrons
________ built the first offshore wind farm in 1991.
Denmark
Vegetable oil ________.
can be burned as fuel
Which of the following statements is NOT accurate regarding geothermal power?
Geothermal power generators are one of the true fully sustainable energy sources.
Commercially available household photovoltaic systems cost approximately $20,000. The average cost of electricity in the United States is approximately $0.09 per kilowatt hour. At these prices how long would it take for the photovoltaic system to generate $20,000 of electricity? Assume the system will produce enough kilowatt hours for a four-person household in Topeka, Kansas.
12.5 years
U.S. hydropower dam construction was greatest during the ________.
1930s to 1960s
Why is there little to no growth expected for hydropower?
Almost all rivers that can be dammed for power generation have been dammed already.
Describe the trends in uranium oxide domestic production from the peak production year to 2005.
Domestic production declined dramatically.
What sort of threat does wind energy pose to certain kinds of wildlife?
Flying creatures such as birds and bats are killed when they fly into wind turbine blades.
If solar, wind, and geothermal sources do play a larger role in U.S. electricity generation in the future, predict what graph (b) might look like in 2050. Select all that apply.
The renewable slice of the pie chart would get bigger. Solar, wind, and geothermal would make up a larger portion of the renewables bar.
How is the sun's energy production different from the process in which energy is produced in current nuclear power plants?
The sun releases energy through nuclear fusion, whereas our current nuclear power technology releases energy through nuclear fission.
________ strongly influences the amount of energy generated from hydropower.
The volume of water released and the height of the fall
Which of the following would indicate that a home is using solar power to generate electricity and is NOT using batteries?
There are solar panels on the roof and power lines going to the home.
Assuming that renewable energy sources will contribute more and more to power generation in the future, do you expect the growth rates for these renewable energy sources to increase or decrease over the next 30-year period (2000 to 2030)?
These growth rates are relative to small absolute numbers. They will most likely decrease as the total contribution by renewables increases.
The major problem impeding the widespread use of solar panels on residential buildings is the __________.
cost of solar panels
According to the data in Step 1, by how much would solar have to grow to match the current level of hydroelectric power?
about 60 times
Corn-based ethanol production has a number of drawbacks, including ________.
all of the above are drawbacks of corn-based ethanol production
Assume that the depletion of nonrenewables requires renewables to account for more than 30% of our energy production by 2040. What annual growth rate of renewables must be achieved in order to meet that goal?
at least 15% annual growth rate
Worldwide, the most widely used renewable energy resource is ________.
bioenergy
Of the following renewable energy resources, which one has the highest life-cycle greenhouse gas emissions?
biomass
What is electrolysis?
the splitting of water into component hydrogen and oxygen
The ultimate source of energy that drives wind power is __________.
the sun
The only energy source(s) from ocean water so far put into commercial production are ________.
tidal electrical generators
Massive solar thermal power plants generate electricity by __________.
using sunlight to boil water, generate steam, and turn the blades of a turbine
Electricity in a wind turbine is generated __________.
when spinning magnets move past a coil of copper wire