Study sets, textbooks, questions
Upgrade to remove ads
APES Chapter 18
Terms in this set (88)
How efficient are fluorescent light bulbs? Incandescent bulbs?
___% of all commercial energy in the US is wasted.
84% (41% because of second law of thermodynamics)
First law of thermodynamics
Energy cannot be created or destroyed
Second law of thermodynamics
Conversions are never 100% efficient - energy is lost as heat
___% of all energy used is wasted by motor vehicles, furnaces, and living and working in leaking buildings.
The US unnecessarily wastes as much energy as ___ of the world's population consumes.
Life cycle cost
Initial cost + lifetime opportunity cost
Four energy devices that waste large amounts of energy and percentage of waste
Incandescent light bulbs (95% waste)
Nuclear power plants (86-92% waste)
Internal combustion engines (75-80% waste)
Coal-burning power plants (66% waste)
Net energy efficiency
A measure of the useful energy we get from a resource after subtracting the energy used and wasted to make the energy available - Includes efficiency of each step in the process of making energy available for use
Two general principles for saving energy
Reduce number of steps in conversion process as much as possible
Strive for highest possible efficiency in each step
Using waste heat to produce electricity
Two forms of energy from the same fuel source
It saves energy to replace energy-wasting electric motors with what?
Adjustable speed drive motors
Best way to save energy in transportation
Increase fuel efficiency of motor vehicles (it would save money, decrease air and water pollution, decrease CO2 emissions)
Corporate average fuel economy
2016 CAFE standards
37.8 mpg for cars
28.8 mpg for trucks
Tier II CAFE addresses what?
Sulfur and nitrogen emissions
Gasoline consumption would be cut in half if Congress required each vehicle to get ___ mpg.
Weakness of hybrid-electric cars
Energy storage - batteries
What are at least twice as efficient as internal combustion engines?
US Green Building Council
Certifies buildings as meeting strict environmental design standards
Green Council's LEED program
Leadership in Energy and Environmental Design - established building standards with a silver, gold, and platinum scoring system that is being increasingly used in the US.
Best design for energy efficiency - airtight, need air-to-air exchange
Cost 5% more to build but pay for themselves within 5 years
In Sweden, these homes use 90% less energy than a typical home in the US
Use walls made of compacted straw covered with plaster or adobe
Covered with plants, provide good insulation, absorb storm water, outlast conventional roofs, make buildings more energy efficient, reduce urban heat island effect
How to save energy in existing buildings
Insulate them, plug leaks, use energy-efficient heating and cooling systems, appliances, and lighting
Low emissivity - cut heat losses by 2/3 and reduce CO2 emissions
Most energy-efficient methods to heat space
2. geothermal heat pump (geoexchange)
3. passive solar heating (orient towards sun - towards south in Northern Hemisphere)
4. conventional heat pump (in warm climates only)
5. high-efficiency natural gas furnace
Cogenerations units about the size of a fridge that run on natural gas or LPG to produce heat and electricity
Most efficient way to heat water
Tankless instant water heater fired by natural gas of LPG
Hydrogen + oxygen
Waste product: water
A way to show heat loss in energy conversions
Efficiency of nuclear power plant vs passive solar heating
Only 14% of original energy usable in power plant
90% usable in passive solar
Nanotechnology that can help make eco cars
Structural insulation panels
Measure of resistance to heat flow
Two ways to promote improving energy efficiency
Government tax breaks
Other economic incentives
Six types of renewable energy
Solar, flowing water, wind, biomass, geothermal, hydrogen
Why is renewable energy not being developed?
There is no financial incentive
Walls and floors made of what collect solar energy and release it slowly?
Concrete, adobe, brick, stone, water in containers
Energy-saving systems add about ___% to the cost of a house, but the life cycle cost is ___-___% lower.
What do solar thermal systems do?
Collect and transform radiant anergy to high-temperature thermal energy (heat), which can be used directly or converted to electricity.
Central receiver system/power tower
Focused rays - very strong
Computer-controlled mirrors that track and focus the sunlight on a central heat collection tower
What does a solar thermal plant do?
Collects sunlight and focuses it on oil-filled pipes running through the middle of a large area with curved solar collectors - can be large or small
Inexpensive devices that concentrate sunlight to cook food - reduce indoor air pollution, deforestation, save time and labor of collecting wood
Convert solar energy directly into electrical energy - transparent wafers that are energized by sunlight, causing electrons in the semiconductor to flow, creating an electrical current
PV cells key ingredient
Advantages to solar cells
They last up to 30 years, are quickly installed, easily expandable, no CO2 emissions, reliable, quiet, minimal maintenance
Solar cells currently supply ___% of the world's electricity, but by 2040 they could supply ___%.
Using a high dam across a large river to create a reservoir
Using a low dam with little or no reservoir across a small stream with turbines turned by the stream's flow
Using surplus electricity from a conventional power plant to pump water from a lower reservoir to a higher one for release through a turbine when more electricity is needed (peak periods)
Hydropower supplies ___% of the world's electricity.
World's most rapidly growing form of indirect solar energy
Between 1995 and 2004, the use of wind power increase _____-fold and the price decrease _____-fold.
What country gets 90% of its electricity from wind?
What six states could produce enough wind electricity to meed the US's needs?
North and South Dakota, Kansas, Nebraska, Oklahoma, Texas
Advantages of wind electricity
Moderate to high net energy
Comparable to coal in some areas
(Study PPT slide)
Disadvantage of wind electricity
May disrupt birds' migratory patterns
Single solar cell: sides are enriched with what? (two things)
Biomass can be converted into what forms of biofuels?
Solid, liquid, or gas
Biomass makes up ___% of the energy used in the poorest countries.
Examples of biofuels made from biomass
Liquid methanol, wood alcohol, ethanol
Biogas is a mixture of ___% methane and ___% CO2.
BMW's plant in Spartanburg, SC gets over ___ of its electricity and ___ of its heat by burning methane gas from a nearby landfill.
1/4 of electricity
1/10 of heat
Ethanol can be made from what?
Sorghum, sugar cane, sugar beets, corn, rice, sunflowers
What process in the conversion of biomass results in net energy loss?
Using industrialized farming to produce the crops
Gasoline + ethanol
Methanol is generally made from natural gas and can be produced from what three things?
CO2, coal, biomass
Geothermal heat pumps
Use a pipe and duct system to bring heat stored in underground rocks and fluids - heat source in winter, heat sink in summer
Uses buried pipes filled with fluid to move heat in or out of the ground for heating/cooling needs - most energy-efficient, cost-effective, cleanest way to heat a building
No water droplets
Steam and water droplets
Sources of geothermal energy
Wet and dry steam, hot water trapped in porous or fractured rocks, molten rock (magma), hot dry-rock zones, warm-rock reservoir deposits
Anaerobic digestion - break down organic waste, produce biogas (55-70% methane)
___% of Iceland's buildings and ___% of its energy is provided by geothermal energy.
Four problems with geothermal energy
Too expensive to tap except for the most concentrated and accessible areas
May be depleted if heat is removed faster than it can be renewed
Three problems with use of hydrogen as fuel
It is chemically locked up in water and organic compounds
It takes energy and money to produce hydrogen from water and organic compounds (NOT a source of energy - a fuel produced by using energy)
Current versions of fuel cells are expensive but are the best way to use hydrogen
Methods of producing hydrogen
Reforming, thermolysis, from algae, coal gasification
Why might hydrogen be safer than gasoline?
It disperses into the atmosphere quickly
Is hydrogen easier or harder to store than electricity?
Major changes to make to shift towards sustainability
Reduce dependence on fossil fuels
Reduce CO2 emissions
Phase in full-cost pricing of fossil fuels
Tax breaks for sustanability
Invest more in public transportation
More research, government subsidies
Small power systems that generate 1-10,000 kilowatts of power
Ways the government can increase/decrease the use of stuff
Subsidies, taxes, tax breaks, regulations
Two basic strategies for stimulating or dampening the use of a particular resource
Price regulation stuff
Keep energy prices artificially low to encourage selected resources
Keep prices artificially high to discourage use
Increase taxes on fossil fuels
Encourage improvements in energy efficiency
Absolute best ways to achieve sustainability
Low-temperature solar heating (passive) and improved energy efficiency
Sets found in the same folder
APES Chapter 16
#OMG APES REVIEW
APES Chapter 5
APES Chapter 20
Sets with similar terms
chapter 15 and 16 APES Test
Renewable Energy Resources
APES Chapter 16
APES Chapter 16
Other sets by this creator
Stats Test 2
Stats Test 1
SPN 430 Midterm Identifications
SPN 430 Midterm: Authors