Search for notes by fellow students, in your own course and all over the country.
Browse our notes for titles which look like what you need, you can preview any of the notes via a sample of the contents. After you're happy these are the notes you're after simply pop them into your shopping cart.
Document Preview
Extracts from the notes are below, to see the PDF you'll receive please use the links above
Chapter 13
Name: Sarah Montgomery
Date: 2
...
16
Section: Achieving Energy Sustainability
Questions/Main
Ideas/Vocabulary
Period: F
Notes/Answers/Definitions/Examples/Sentences
Nonrenewable
An energy reservoir that is being depleted much faster than it is
being replenished
...
Non depletable
These are sources that cannot be depleted no matter how much
they’re used
...
Before fossil fuels and even today in
underdeveloped countries, renewable energy was all that was
available to people (in modern sub-Saharan Africa, it’s 86% of
energy and mostly not harvested sustainably)
...
If harvested unsustainably, there’s
cons: wood= deforestation, wind= killing birds and bats,
hydroelectric= killing fish, solar panels= lots of water and metal
...
You could lower your
thermostat, ride your bike to work, use power strips, etc
...
People also conserve by using more energy efficient appliances
...
LED
lights use 1/6 as much energy as incandescent bulbs
...
Also, important to consider the heat losses that mean we’re
actually saving more energy
...
Peak demand
The greatest quantity of energy used at any one time
...
When plants are
unable to handle the demand, things like blackouts happen
...
Passive solar design
A technique of building that takes advantage of solar radiation to
maintain a comfortable temperature in the building
...
Also,
double-paned windows insulate while still allowing incoming
solar radiation to warm the house
...
Also, people use
recycled materials for building
...
Materials with high
thermal inertia stay ho once they’ve been heated and cool once
they’ve been cooled
...
Biofuels
Liquid forms of biomass
...
5%
total in US
...
The Sun is the ultimate source of fossil fuels
...
Burning biomass fuels produces a variety of air pollutants,
including particulate matter, carbon monoxide, and nitrogen
oxides, which are components of photochemical smog
...
Depending on the plant it comes from, the carbon dioxide could
have been captured through photosynthesis a few months ago
(like corn plants) or several hundred years ago (like large trees)
...
This carbon has been buried for millions of years
...
Carbon neutral
An activity that does not change atmospheric CO2
concentrations
...
Net removal
Removing more timber than is replaced by growth of forest is an
unsustainable practice that leads to deforestation
...
Pulp and paper industries, power plants, and other
industries use wood waste for energy
...
Tree removal is sustainable only if trees get time to regrow
...
Also,
charcoal fire produces less smoke and needs less attention
...
It can be beneficial because
it removes microorganisms from the surroundings, reducing the
risk of disease transmission
...
The problem is
exacerbated when the manure is burned indoors in poorly
ventilated rooms
...
5 million deaths annually
...
It is
made by converting starches and sugars from plant material into
alcohol and carbon dioxide
...
The US is the world leader in ethanol production,
manufacturing 9 billion gallons in 2008
...
Ethanol is usually mixed with gasoline, most commonly at a
ratio of one part ethanol to nine parts gasoline
...
Biodiesel
A substitute for regular petroleum diesel
...
Flex-fuel vehicles
Can run on either gasoline or E-85
...
Also, growing corn to produce ethanol uses a lot of fossil
fuel energy and a lot of land
...
Biodiesel
A direct substitute for petroleum-based diesel fuel
...
Higher
concentrations of biodiesel work effectively only in modified
engines
...
Most biodiesel comes from soybean oil or processed vegetable
oil
...
Some species of
algae appear to have great potential for producing biodiesel: it’s
grown everywhere, produce greatest yield of fuel, and utilize
least energy and fertilizer
...
Hydroelectricity
Electricity generated by the kinetic energy of moving water
...
Although impounding water from rivers and streams behind
dams is the most common approach, run-of-the-river and tidal
energy systems also work
...
The
further distance the water calls, the more potential energy, the
more electricity
...
They reduce environmental impact bc relatively little flooding and
seasonal changes are not disrupted
...
Water impoundment
Storing water in a reservoir behind a dam
...
Dam operators control the
gates, thus determining the flow rate of water and amount of
electricity
...
The Three Gorges Dam on the Yangtze
River is the largest dam in the world
...
It uses
gates and turbines similar to those used in the run-of-the-river
and water impoundment systems to capture the kinetic energy of
water flowing through estuaries, rivers, and bays and convert it
into electricity
...
In some places, the difference between high and low tide isn’t
enough
...
Sustainability of
hydroelectricity
Major dams have brought a lot of renewable energy
...
They generate a lot of electricity without air
pollution, waste products, or CO2
...
Also,
the reservoir behind a dam can be used for recreational and
economic opportunities and provides flood control
...
It also affects the species dependent on
free-flowing rivers
...
Also, the plants that are flooded decompose
and release methane
...
Siltation
The accumulation of sediments on the bottom of a reservoir
...
The only way to reverse siltation is by dredging: removal of the
sediment, usually with machinery that runs on fossil fuels
...
Several applications, like window placement and building homes
into hills
...
Active solar energy
Technologies that capture energy of sunlight with the use of
other technologies
...
Solar heating systems
Range from providing domestic hot water and heating swimming
pools to a variety of building heating purposes
...
The circulation of the liquid is either driven by
a pump or by natural convection
...
The heated water
flows back to an insulated storage tank
...
The systems
typically include a backup energy source so that ho water is
available in coldness/ cloudiness
...
It uses certain semiconductors to
generate a low-voltage electric current that is converted into
higher-voltage alternating currents for use in buildings
...
They’re used in several ways; solar
panels can be used to supply electricity or batteries, majority of
systems are tied to the electrical grid (extra electricity is sent to
the electric company which buys it or gives the customer credit),
or are used in locations far from the “grid” where small amounts
of electricity are needed on a regular basis
...
They use
lenses or mirrors and tracking systems to focus the sunlight
falling on a large area into a small beam
...
They’re best constructed in expansive desert
areas (large and lots of sun)
...
They also produce electricity when it
is needed most: on hot, sunny days (people need AC)
...
Bad: PV (photovoltaic) solar panels are expensive and the
payback period is long (but in the US, recent tax breaks are
making solar electricity and water heating more attractive)
...
Also, panels have to
be recycled properly
...
Harvesting geothermal
energy
Hot groundwater can be piped directly to household radiators for
heating a home
...
Steam from water evaporated by Earth’s internal heat turns
turbines to create electricity
...
However, we have to
be careful not to collect too much groundwater or else the cycle
can’t keep going
...
Currently in operation in CA, NV, HI, and UT
...
Ground source heat
pumps
They take advantage of the high thermal inertia of the ground
...
Earth’s temperature about 3 m (10 ft
...
The heat tapped is solar energy
...
Winter: The slightly warmed fluid is
compressed in the heat pump to increase its temp even more,
and the heat is distributed throughout the house
...
Summer: Fluid is cooled underground and pulls
heat from the house as it circulates
...
Winds are the result of the unequal heating of Earth’s surface by
the Sun
...
US obtains less than
1% of electricity from wind; largest amounts in CA and TX
...
It is practical to group turbines
into wind farms/parks
...
People want to build one off of Cape Cod in MA
...
Wind is Nondepletable, clean, and free
...
Therefore, wind electricity produces no pollution or greenhouse
gases
...
However, most off-grid residential wind energy systems require
batteries t store energy—batteries are expensive to produce and
hard to dispose of/recycle
...
Also, the blades kill many birds and bats
...
In a battery, electricity is generated by a reaction between two
chemical reactants, such as nickel and cadmium
...
Eventually the reactants are used up and the
battery died
...
2 H2+ O2 à energy + 2H2O
The basic process forces protons from hydrogen gas through a
membrane, while the electrons take a different pathway
...
Using a hydrogen fuel cell requires a supply of hydrogen that is
a challenge because free hydrogen gas is rare and explosive
...
Currently, most commercially available
hydrogen is produced by an energy-intensive process of burning
natural gas in order to extract its hydrogen, leaving carbon
dioxide as a waste product
...
Electrolysis
An alternative process to producing hydrogen; an electric current
is applied to water to “split” it into hydrogen and oxygen
...
Is hydrogen a viable
energy alternative?
Hydrogen fuel cells are considered by some policy makers to be
the future of energy and the solution to many of the world’s
problems; they’re 80% efficient and their only by product is
water
...
Also, suppliers
need a safe distribution network; in a fuel cell vehicle, it’d
probably be stored in a gas in a large tank under high pressure
...
Using solar
wind to produce hydrogen would lower the environmental cost
even more, and the energy supply would be renewable
...
The challenge of a
renewable energy strategy
Innovation and technologic advances provide the driving force
for moving from one energy technology to the next
...
Improving the electrical
grid
US needs to upgrade its existing electrical infrastructure
...
The
distribution system is outdated and subject to overloads of
outages which cost the economy over $100 billion per year
...
An energy economy based on Nondepletable energy
resources requires reliable electricity storage and affordable
distribution networks
...
Our current infrastructure relies on a system of large energy
producers—regional electricity generation plants
...
Some energy
experts maintain that a better system would consist of a large
number of small scales electricity “parks” that rely on
nonrenewable and renewable sources
...
Smart grid
An efficient, self-regulating electricity that accepts any source of
electricity and distributes it automatically to end-users
...
Smart appliances would use electricity at
the best time
...
The cost of renewable energy has been falling
...
Researchers will develop solutions to the problem of creating
efficient energy storage systems
...
·
Renewable energy resources include Nondepletable energy resources, like the Sun wind
and moving water, and potentially renewable energy resources, like biomass (available as
long as used sustainably)
·
Turning down the thermostat and driving fewer miles are examples of steps people can
take t conserve energy
...
Reducing demand for energy can be an
equally effective or more effective means of achieving energy sustainability than developing
additional sources
...
In theory, it its carbon neutral
...
Run-of-the-river impound little or no water; less electricity but less impact
...
Geothermal can heat
buildings directly or be used to generate electricity—however, plants can be located only in
places where it is accessible
...
The only waste product from a hydrogen fuel cell is water, but obtaining
hydrogen gas for use in fuel cells is energy intensive
...
·
Although many scenarios have been predicted for the world’s energy future, conserving
energy, increasing energy efficiency, a greater reliance on renewable energy sources, and
new tech to improve energy distribution and storage will all be necessary for achieving energy
sustainability
MULTIPLE CHOICE
·
Which of the following is not an example of a potentially renewable/Nondepletable energy
source?
o © nuclear energy
·
Renewable energy sources are best described as
o (e) those that are reusable, and therefore eliminate waste energy released into the
environment
·
An energy efficient building might include al of the following except
o (a) building materials with low thermal inertia
·
Which of the following is not solar based?
o © tides
·
which of the following demonstrates the use of passive solar energy?
o (e) photovoltaic solar cells and solar ovens
·
a stud of small wind turbines in the Netherlands tested the energy output of several
models