Chapter 16

drawbacks to wind power

-areas w/greatest wind power potential are often sparsely populated and located far from cities -wind can die down (need a backup) -low level noise bothers some people

how to cool buildings naturally

-block the sun with shade trees -use a light colored roof -use geothermal heat pumps for cooling

problem w/ depending on solid biomass as a fuel

-clearing of forests to provide the fuel reduces the amount of vegetation that would capture co2

ways industries can improve energy efficiency

-cogeneration - uses a combined heat and power system (CHP), steam used to generate electricity is reused (produces two useful forms of energy from one fuel source) -use more energy-efficient electric motors -run at the minimum rate needed for a job -recycling material such as steel`

photovoltaic cells/solar cells

-converts solar energy directly into electrical energy -have no moving parts and they operate safely -less dev countries are starting to get energy through this -could recharge hybrid cars -no co2 emission but used to make panels

4 energy inefficient devices

-data centers - run on full capacity regardless of demand and need large amounts of energy to cool -internal combustion engine - only 20% of money people use for gasoline gets put to good use -nuclear power plant - 80% waste -coal-fired power plant - wastes 65% of energy

benefits of hydrogen

-eliminate most of the outdoor air pollution that comes form motor vehicles and coal burning power plants -reduce threats of climate change

smart grid

-energy-efficient, digitally controlled, ultra high voltage system w/superefficient transmission lines -expensive

ways to capture geothermal energy

-geothermal heat pump system - heat and cool a house by exploiting the temperature difference between the earth's surface and underground -tap into deeper hydrothermal reservoirs of geothermal energy by drilling wells to extract

why are we still wasting so much energy and money?

-gov subsidies to inefficient energy sources -too few gov tax breaks for consumers that invest in improving energy efficiency

advantages of large scale hydropower

-high net energy yield -large untapped potential -low-cost electricity

energy-efficient vehicles

-hybrid car - battery powered electric motors -plug-in hybrid electric vehicle - can travel 30 - 60 miles on electricity alone (Drawback: $$$$$)

save money and energy of existing buildings

-insulate the building and plug leaks -use energy-efficient windows -stop other heating and cooling losses -have energy efficient lighting

disadvantages of large scale hydropower

-large land disturbance and displacement of people -high methane emissions from rapid biomass decay in shallow tropical reserves

drawbacks to biofuels

-loss of biodiversity -farmers reduce water supplies

advantages of passive of active solar heating

-medium net energy yield -low emissions of co2

disadvantages of passive of active solar heating

-need access to sun 60% of time during the day -sunlight can be blocked by trees and other structures -need a backup system on cloudy days

problems to solar thermal systems

-net energy yield is low (means that it need a lot of gov subsidies) -water shortages may limit the production of electricity

problem w/solar cells

-not highly energy efficient (low to medium net energy yield) -$$$$$

biodiesel

-produced from vegetable oil extracted from soybeans, sunflowers, oil palms -topsoil loss and fertilizer runoff when growing these crops -emissions of greenhouse gases

living roofs/green roofs

-reduces the cost of cooling and heating a building by absorbing heat from the summer sun and helping to insulate the structure during the winter

superinsulation

-so heavily insulated that heat from sunlight and human bodies can warm it with little or no need for a backup heating system

How to use more sustainable buildings

-solar energy and chemical cycles principles of sustainability by using energy more efficiently and using more renewable sources of energy resources, etc EX: if a building is facing the sun it can get more of its heat from the sun

advantages to wind power

-wind is abundant -wind farm can be built in 9 to 12 months -small land footprint -don't need cooling like other power plants -high net energy yield

3 major advantages of biofuels

1)biofuel crops can be grown throughout much of the world 2)if these crops are not used faster than they are replenished, there is no net increase in co2 emissions 3)easy to store and transport through existing fuel networks

if renewable energy is so great why is it only 8% of the world's energy source?

1)gov subsidies have been lower for dev of renewable energy than those for fossil fuels 2)gov subsidies for renewable energy is not guaranteed 3)prices we pay for nonrenewable fossil fuels does not include harmful env costs (which makes it cheaper for us)

3 challenges in turning the vision of hydrogen as a fuel into reality

1)hardly any hydrogen gas in the earth's atmosphere so it must be produced by hydrogen (this process is $$$$$ and takes energy, resulting in a negative net energy yield) 2)fuel cells are the best way to use h2 to produce electricity, but current fuel cells are $$$$$... 3)less co2 and air pollution depends on how h2 is produced

3 strategies gov can use to help stimulate or reduce short-term and long term of a particular energy source

1)keep the prices of selected energy resources artificially low to encourage use of those resources 2)allow the prices of selected energy resources to rise to their natural marker levels by removing gov subsidies 3)emphasize consumer education

3 general conclusions for future energy sources

1)there will be a gradual shift from large centralized macropower to smaller micropower systems 2)improved energy efficiency and carefully regulated use of natural gas will be the best way to transition to using mostly renewable energy sources 3)because fossil fuels are still abundant, we will continue to use them

wind power is that world's ____ fastest growing source of energy after ______

2nd solar cells

wind power has the potential to produce ____ times the world's current use of electricity

40

top 4 producers of hydropower

China, Canada, Brazil, US

3 countries where wind farms have been rapidly built on

Europe, China, US

The most simple and abundant chemical element in the universe

Hydrogen

passive vs active solar heating systems

Passive solar energy uses the heat of the sun, while an active solar system uses the sun's radiation, which it converts to electricity to power systems in your home

wind energy production states

Texas, California, Iowa

largest producer of geothermal electricity from hydrothermal reservoir

US

biggest producers of liquid biofuels

US, Brazil, European Union, China

passive solar heating systems

absorbs and stores heat from the sun directly within a well-insulated structure

drawback to ethanol

affordable chemical processes for converting cellulosic material to ethanol are still being developed

hydropower

any technology that uses the kinetic energy of flowing and falling water to produce electricity -indirect form of solar energy

active solar heating system

captures energy from the sun by pumping a heat-absorbing fluid through special collectors, usually mounted on a roof

community solar/solar gardens

communities are installing shared solar-cell arrays

uses of solar biomass

cooking heating generate electricity

we can use ocean tides and waves for energy

dams can be built across the mouths of such bays to capture energy in these flows for hydropower

fuel cell

device that used hydrogen gas as a fuel to produce electricity -reduce co2 emissions and climate change (Drawback: $$$$$ and h2 has negative net energy yield)

geothermal energy

heat stored in soil, underground rocks, and fluids in the earth's mantle

ethanol

made from plants such as sugarcane, corn, etc -process involves converting plant starches or other plant materials into simple sugars

energy efficiency

measure of how much useful work we can get done per unit of energy

biomass

plant materials that we can burn directly as a solid fuel or convert into gaseous or liquid biofuels -indirect form of solar energy b/c it consists of combustible organic compounds produced from photosynthesis

cellulosic ethanol

produced from inedible cellulose that makes up most of the biomass such as plants (leaves, wood chips, etc)

how to improve fuel efficieny

reduce it's weight by using stuff like ultralight and ultrastrong composite materials (doesn't require painting)

wood is a ______ resource only if it is not harvested faster than it is replenished

renewable -less dev countries -> fuel wood crisis: forced to cut through forests faster than it can be replenished to meet needs -solution: have biomass plantations and plant fast-growing trees, shrubs

solar thermal systems/concentrated solar power(CSP)

use different methods to collect and concentrate solar energy in order to boil water and produce steam for generating electricity

solar cookers

used to focus the sunlight for boiling water that's used for cooking