SJSU ENVS 119 Final Study Guide Questions Answered Correctly
How is the potential wind power output calculated for a specific site and turbine? (Formula) - Answers
P=0.5 x p x Cp x v^3 x As
p= 1.2kg/m^3
Cp= energy coefficient (.4-.5)
v^3= meters per second (double wind speeds=8 fold in power)
As=m^2 (area swept by blade)
How can the social gap in renewable energy be overcome? - Answers Include more people in the
conversation and what could be the benefit.
Define « intermittent » for wind energy. Why is it a problem? - Answers Wind energy can be on/off
depending on the weather.
Primary source of power for wind energy? - Answers Solar energy
Due to uneven heating of Earths surface
Define payback time for average project in Wind energy. - Answers he amount of time it would take to
save enough money in operation costs to pay for the equipment
How much of CA electricity is likely to be produced from Wind by 2050. - Answers 35%
Passive home design - Answers a system of putting the sun's energy to use without requiring mechanical
devices to distribute the collected heat
Insolation - Answers the delivery rate of solar radiation per unit of horizontal surface
Insulation - Answers A substance that reduces the transfer of thermal energy.
Solar Path - Answers refers to orientation of building so that the sun passes and heats the house
HDD - Answers Correlation on temp. outside vs. temp. inside
How do photovoltaics generate electricity? - Answers a method of converting sunlight to electricity using
layers of materials that either readily give up or absorb electrons
Define: Solar Photovoltaic (PV) - Answers a power system designed to supply usable solar power by
means of photovoltaics
Define: Solar Thermal Energy - Answers energy produced by converting solar energy into electrical
energy through the use of mirrors
, Understand efficiency factor, what is the normal efficiency from PV panels? - Answers Most typical
silicon solar cells have a maximum efficiency of around 15-22%.
Understand energy intermittency of Solar and why energy storage is needed. - Answers solar radiation is
zero at night, and affected by cloud cover and air turbidity during the day.in order that it not be wasted,
as well as offering back-up power in scenarios where renewables are used in some way.
What is EROI and how do you calculate it? - Answers Energy Return on Investment (EROI) is the amount
of energy that has to be expended in order to produce a certain amount of energy.EROI = Energy Output
/ Energy Input
EPBT - Answers Energy Pay Back Time
Why are a majority of renewable energy projects are now able to compete with fossil fuels on the
market place, even without subsidies? - Answers the unsubsidized cost of solar and wind power has
already reached parity with conventional fossil fuels in many parts of the United States.
LCA Category - Answers Life-Cycle Assessment: a technique to assess environmental impacts associated
with all the stages of a product's life from raw material extraction through materials processing,
manufacture, distribution, use, repair and maintenance, and disposal or recycling
system boundaries - Answers the border between a system and the rest of the environment
functional unit - Answers a quantified description of the performance requirements that the product
system fulfills
Define 1st Generation biofuels - Answers refer to the fuels that have been derived from sources like
starch, sugar, animal fats and vegetable oil. The oil is obtained using the conventional techniques of
production. (firewood)
Define 2nd Generation biofuels - Answers also known as advanced biofuels, are fuels that can be
manufactured from various types of non-food biomass. Biomass in this context means plant materials
and animal waste used especially as a source of fuel.
Define 3rd Generation biofuels - Answers refers to biofuel derived from algae. Previously, algae were
lumped in with second generation biofuels.
What are the options to produce a biofuel version of Diesel? - Answers Biodiesel refers to a vegetable
oil- or animal fat-based diesel fuel consisting of long-chain alkyl (methyl, ethyl, or propyl) esters.
Biodiesel is typically made by chemically reacting lipids (e.g., vegetable oil, soybean oil, animal fat with
an alcohol producing fatty acid esters
What are the options to produce a biofuel version of Gasoline (ie: Ethanol) - Answers Most ethanol in
the United States is produced from starch-based crops by dry- or wet-mill processing
How is the potential wind power output calculated for a specific site and turbine? (Formula) - Answers
P=0.5 x p x Cp x v^3 x As
p= 1.2kg/m^3
Cp= energy coefficient (.4-.5)
v^3= meters per second (double wind speeds=8 fold in power)
As=m^2 (area swept by blade)
How can the social gap in renewable energy be overcome? - Answers Include more people in the
conversation and what could be the benefit.
Define « intermittent » for wind energy. Why is it a problem? - Answers Wind energy can be on/off
depending on the weather.
Primary source of power for wind energy? - Answers Solar energy
Due to uneven heating of Earths surface
Define payback time for average project in Wind energy. - Answers he amount of time it would take to
save enough money in operation costs to pay for the equipment
How much of CA electricity is likely to be produced from Wind by 2050. - Answers 35%
Passive home design - Answers a system of putting the sun's energy to use without requiring mechanical
devices to distribute the collected heat
Insolation - Answers the delivery rate of solar radiation per unit of horizontal surface
Insulation - Answers A substance that reduces the transfer of thermal energy.
Solar Path - Answers refers to orientation of building so that the sun passes and heats the house
HDD - Answers Correlation on temp. outside vs. temp. inside
How do photovoltaics generate electricity? - Answers a method of converting sunlight to electricity using
layers of materials that either readily give up or absorb electrons
Define: Solar Photovoltaic (PV) - Answers a power system designed to supply usable solar power by
means of photovoltaics
Define: Solar Thermal Energy - Answers energy produced by converting solar energy into electrical
energy through the use of mirrors
, Understand efficiency factor, what is the normal efficiency from PV panels? - Answers Most typical
silicon solar cells have a maximum efficiency of around 15-22%.
Understand energy intermittency of Solar and why energy storage is needed. - Answers solar radiation is
zero at night, and affected by cloud cover and air turbidity during the day.in order that it not be wasted,
as well as offering back-up power in scenarios where renewables are used in some way.
What is EROI and how do you calculate it? - Answers Energy Return on Investment (EROI) is the amount
of energy that has to be expended in order to produce a certain amount of energy.EROI = Energy Output
/ Energy Input
EPBT - Answers Energy Pay Back Time
Why are a majority of renewable energy projects are now able to compete with fossil fuels on the
market place, even without subsidies? - Answers the unsubsidized cost of solar and wind power has
already reached parity with conventional fossil fuels in many parts of the United States.
LCA Category - Answers Life-Cycle Assessment: a technique to assess environmental impacts associated
with all the stages of a product's life from raw material extraction through materials processing,
manufacture, distribution, use, repair and maintenance, and disposal or recycling
system boundaries - Answers the border between a system and the rest of the environment
functional unit - Answers a quantified description of the performance requirements that the product
system fulfills
Define 1st Generation biofuels - Answers refer to the fuels that have been derived from sources like
starch, sugar, animal fats and vegetable oil. The oil is obtained using the conventional techniques of
production. (firewood)
Define 2nd Generation biofuels - Answers also known as advanced biofuels, are fuels that can be
manufactured from various types of non-food biomass. Biomass in this context means plant materials
and animal waste used especially as a source of fuel.
Define 3rd Generation biofuels - Answers refers to biofuel derived from algae. Previously, algae were
lumped in with second generation biofuels.
What are the options to produce a biofuel version of Diesel? - Answers Biodiesel refers to a vegetable
oil- or animal fat-based diesel fuel consisting of long-chain alkyl (methyl, ethyl, or propyl) esters.
Biodiesel is typically made by chemically reacting lipids (e.g., vegetable oil, soybean oil, animal fat with
an alcohol producing fatty acid esters
What are the options to produce a biofuel version of Gasoline (ie: Ethanol) - Answers Most ethanol in
the United States is produced from starch-based crops by dry- or wet-mill processing
