EGR 240 Final Exam with all Correct & 100% Verified
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Which of the following energy sources are initially from the sun's energy? (choose all that apply).
geothermal
concentrating solar thermal power
photovoltaic
hydroelectric
wind
nuclear
coal ✔Correct Answer-concentrating solar thermal power
photovoltaic
hydroelectric
wind
coal
Roughly what percentage of the sun's energy hitting the earth ends up hitting the earth's surface?
roughly 40%
roughly 50%
roughtly 60%
roughly 75% ✔Correct Answer-roughly 50%
How does the power from the sun to the earth compare to the average power use by current
civilization?
Total power from the sun is comparable to about 50% of the world's average power use by
civilization.
Total power from the sun is comparable to about 5 times the world's average power use by
civilization.
Total power from the sun is comparable to about 50 times the world's average power use by
civilization.
Total power from the sun is comparable to about 5000 times the world's average power use by
civilization. ✔Correct Answer-Total power from the sun is comparable to about 5000 times the
world's average power use by civilization.
The term insolation means:
The ability of a material to resist the flow of heat.
The average power from the sun hitting a square meter area over a period of time (typically per day
or per year)
The average energy from the sun hitting a square meter area over a period of time (typically per day
or per year)
The ability of photovoltaics to convert light into electricity. ✔Correct Answer-The average energy
from the sun hitting a square meter area over a period of time (typically per day or per year)
Which items below affect the solar insolation of a location? (Select all that apply.)
clouds or haze
altitude
longitude
latitude ✔Correct Answer-clouds or haze
altitude
,latitude
What energy sources are directly powered by solar energy ? ✔Correct Answer-biomass fuels, solar
thermal, ocean thermal, waves, photovoltaic
What energy sources are indirectly powered by solar energy? ✔Correct Answer-Tidal and
geothermal
How much solar power does Earth (in total) receive from the sun? ✔Correct Answer-174 Petawatts
How much total solar power is available on earth's surface? ✔Correct Answer-More than 89 PW
solar power on earths surface
How much total power is available on earth's surface? ✔Correct Answer-about 93,000 TW
How much power do we get from the Sun on average? W/m^2 ✔Correct Answer-188 W/m^2
What is solar irradiance? ✔Correct Answer-power/area
What is solar insolation? ✔Correct Answer-energy/area over a period of time (usually a day or a
year) kWh/m2 per day
Insolation also sometimes called _____ _____ ✔Correct Answer-solar irradiation
What is the average solar insolation on earth's surface? ✔Correct Answer-
What are the two major technologies by which we generate electricity from solar power, and in what
situations is one better than the other? ✔Correct Answer-photovoltaics and solar thermal. csp is
better when the sky is clear with no clouds (i.e. in deserts). pv is needs light but it doesn't have to be
direct (sill ok under haze)
What are photovoltaics? ✔Correct Answer-materials that directly convert light into electricity
what are parabolic troughs? ✔Correct Answer-parabolic mirrors that concentrate the energy from
the sun on a pipe that runs the length of the mirror. tilt during the day east to west to track the
movement of the sun. pipe in the mirrors can carry an oil or molten salt that can withstand very high
temperatures. heated fluid is pumped to a heat exchanger where it is used to heat water to create
steam to drive steam turbines
where is the largest parabolic trough? ✔Correct Answer-SEGS (California): 354 MW
what is a solar power tower? ✔Correct Answer-hundreds or thousands or hundreds of thousands
of mirrors that all focus power to a tower. heat from the sun is used to heat water into steam, which
can then run electric turbines. more efficient than troughs
what is the largest solar power tower in the world? ✔Correct Answer-Ivanpah (California): 377
MW. 3 towers and 300,000 mirrors. each controlled separately to track the sun during the day
what is solar thermal? (concentrating solar power) ✔Correct Answer-concentrates the light of the
sun for heat. that heat can be used to drive a thermal engine to be used to generate electricity
, What is irradiance? ✔Correct Answer-Power delivered per unit area (W/cm2)
Where and what is the largest solar tower plant in the world? ✔Correct Answer-Ivanpah
(California) - 377 MW
3 advantages of solar thermal ✔Correct Answer-established technology, supplemented generation,
thermal storage
3 disadvantages of solar thermal ✔Correct Answer-requires very direct sunlight, utility scale
system
3 types of photovoltaic ✔Correct Answer-crystalline, polycrystalline, amorphous
crystalline ✔Correct Answer-highest efficiencies (~20%), more expensive
polycrystalline ✔Correct Answer-higher efficiencies (~15%)
amorphous ('thin film') ✔Correct Answer-much cheaper, least efficient (<10% currently)
Swanson Effect ✔Correct Answer-predicts that the price of solar modules tends to decline by
about 20 percent for every doubling of shipped volume
Costs beyond solar cells ✔Correct Answer-'balance of system' (wiring, electronics, support
structure, permitting, inspection, etc)
photovoltaic advantages ✔Correct Answer-does not require direct sunlight (still generating when
overcast sky), suitable for all scales of implementations (residential rooftops, commercial rooftops,
utility scale)
How much solar power (figures, numbers) and energy (example) is available? ✔Correct Answer-
solar power: 100,000 TW
energy: 200 W/m^2
_____% of the Sun's light/energy does not reach the Earth? ✔Correct Answer-45%
Which type of solar power potential, PV or CSP, is higher for the SW desert states (CA, NV, AZ, NM)
and which one is better for Midwest and neighboring regions (IL, IA, KY, NC)? ✔Correct Answer-PV
is better for Midwest and for SW desert states
Typical efficiency for commercial and research PV cells ✔Correct Answer-Commercial approx. 20%
efficient; research laboratory approx. 40% efficient.
In what country was the modern PV cell technology invented? ✔Correct Answer-USA
Enumerate and briefly describe two advantages and two disadvantages of solar PV as per the class
teachings ✔Correct Answer-Advantages: low water requirement, low co2 admissions
Disadvantages: not able to quickly respond to changes in demand, not always able to generate
electricity when needed
Answers |Guaranteed to Pass (Already Graded A+)
Which of the following energy sources are initially from the sun's energy? (choose all that apply).
geothermal
concentrating solar thermal power
photovoltaic
hydroelectric
wind
nuclear
coal ✔Correct Answer-concentrating solar thermal power
photovoltaic
hydroelectric
wind
coal
Roughly what percentage of the sun's energy hitting the earth ends up hitting the earth's surface?
roughly 40%
roughly 50%
roughtly 60%
roughly 75% ✔Correct Answer-roughly 50%
How does the power from the sun to the earth compare to the average power use by current
civilization?
Total power from the sun is comparable to about 50% of the world's average power use by
civilization.
Total power from the sun is comparable to about 5 times the world's average power use by
civilization.
Total power from the sun is comparable to about 50 times the world's average power use by
civilization.
Total power from the sun is comparable to about 5000 times the world's average power use by
civilization. ✔Correct Answer-Total power from the sun is comparable to about 5000 times the
world's average power use by civilization.
The term insolation means:
The ability of a material to resist the flow of heat.
The average power from the sun hitting a square meter area over a period of time (typically per day
or per year)
The average energy from the sun hitting a square meter area over a period of time (typically per day
or per year)
The ability of photovoltaics to convert light into electricity. ✔Correct Answer-The average energy
from the sun hitting a square meter area over a period of time (typically per day or per year)
Which items below affect the solar insolation of a location? (Select all that apply.)
clouds or haze
altitude
longitude
latitude ✔Correct Answer-clouds or haze
altitude
,latitude
What energy sources are directly powered by solar energy ? ✔Correct Answer-biomass fuels, solar
thermal, ocean thermal, waves, photovoltaic
What energy sources are indirectly powered by solar energy? ✔Correct Answer-Tidal and
geothermal
How much solar power does Earth (in total) receive from the sun? ✔Correct Answer-174 Petawatts
How much total solar power is available on earth's surface? ✔Correct Answer-More than 89 PW
solar power on earths surface
How much total power is available on earth's surface? ✔Correct Answer-about 93,000 TW
How much power do we get from the Sun on average? W/m^2 ✔Correct Answer-188 W/m^2
What is solar irradiance? ✔Correct Answer-power/area
What is solar insolation? ✔Correct Answer-energy/area over a period of time (usually a day or a
year) kWh/m2 per day
Insolation also sometimes called _____ _____ ✔Correct Answer-solar irradiation
What is the average solar insolation on earth's surface? ✔Correct Answer-
What are the two major technologies by which we generate electricity from solar power, and in what
situations is one better than the other? ✔Correct Answer-photovoltaics and solar thermal. csp is
better when the sky is clear with no clouds (i.e. in deserts). pv is needs light but it doesn't have to be
direct (sill ok under haze)
What are photovoltaics? ✔Correct Answer-materials that directly convert light into electricity
what are parabolic troughs? ✔Correct Answer-parabolic mirrors that concentrate the energy from
the sun on a pipe that runs the length of the mirror. tilt during the day east to west to track the
movement of the sun. pipe in the mirrors can carry an oil or molten salt that can withstand very high
temperatures. heated fluid is pumped to a heat exchanger where it is used to heat water to create
steam to drive steam turbines
where is the largest parabolic trough? ✔Correct Answer-SEGS (California): 354 MW
what is a solar power tower? ✔Correct Answer-hundreds or thousands or hundreds of thousands
of mirrors that all focus power to a tower. heat from the sun is used to heat water into steam, which
can then run electric turbines. more efficient than troughs
what is the largest solar power tower in the world? ✔Correct Answer-Ivanpah (California): 377
MW. 3 towers and 300,000 mirrors. each controlled separately to track the sun during the day
what is solar thermal? (concentrating solar power) ✔Correct Answer-concentrates the light of the
sun for heat. that heat can be used to drive a thermal engine to be used to generate electricity
, What is irradiance? ✔Correct Answer-Power delivered per unit area (W/cm2)
Where and what is the largest solar tower plant in the world? ✔Correct Answer-Ivanpah
(California) - 377 MW
3 advantages of solar thermal ✔Correct Answer-established technology, supplemented generation,
thermal storage
3 disadvantages of solar thermal ✔Correct Answer-requires very direct sunlight, utility scale
system
3 types of photovoltaic ✔Correct Answer-crystalline, polycrystalline, amorphous
crystalline ✔Correct Answer-highest efficiencies (~20%), more expensive
polycrystalline ✔Correct Answer-higher efficiencies (~15%)
amorphous ('thin film') ✔Correct Answer-much cheaper, least efficient (<10% currently)
Swanson Effect ✔Correct Answer-predicts that the price of solar modules tends to decline by
about 20 percent for every doubling of shipped volume
Costs beyond solar cells ✔Correct Answer-'balance of system' (wiring, electronics, support
structure, permitting, inspection, etc)
photovoltaic advantages ✔Correct Answer-does not require direct sunlight (still generating when
overcast sky), suitable for all scales of implementations (residential rooftops, commercial rooftops,
utility scale)
How much solar power (figures, numbers) and energy (example) is available? ✔Correct Answer-
solar power: 100,000 TW
energy: 200 W/m^2
_____% of the Sun's light/energy does not reach the Earth? ✔Correct Answer-45%
Which type of solar power potential, PV or CSP, is higher for the SW desert states (CA, NV, AZ, NM)
and which one is better for Midwest and neighboring regions (IL, IA, KY, NC)? ✔Correct Answer-PV
is better for Midwest and for SW desert states
Typical efficiency for commercial and research PV cells ✔Correct Answer-Commercial approx. 20%
efficient; research laboratory approx. 40% efficient.
In what country was the modern PV cell technology invented? ✔Correct Answer-USA
Enumerate and briefly describe two advantages and two disadvantages of solar PV as per the class
teachings ✔Correct Answer-Advantages: low water requirement, low co2 admissions
Disadvantages: not able to quickly respond to changes in demand, not always able to generate
electricity when needed
