Chap18 APES
Describe how we can save energy in homes by using (a) superinsulated houses, (b) strawbale houses, and (c) eco-roofs.
(A.) Typically cost about %5 more to build than a conventional home, but can use 90% less energy for heating and cooling that the typical American house. (B.) Depending on the thickness of the bales, plastered strawbale walls have an insulating value compared to a conventional house. Their also great insulators(C.)Can provide good insulation, abosorb storm water and realease it slowly, outlast conventional roofs, and making buildings and homes more energy efficient.
Describe 3 ways to cool houses naturally.
3 ways to cool houses naturally include: superinsulation and superinsulating windows, open windows to take advantage of breezes, and use fans to keep air moving.
List 6 ways to reduce energy waste in existing homes.
6 ways to reduce energy waste in existing homes is by insulating them, plugging leaks, and using energy-efficient heating and cooling systems, appliances, and lightning.
How much of the energy used in the United States is wasted? What percentage is wasted because of the second law of thermodynamics, and what percentage is wasted unnecessarily?
84% fo energy used in the United States is wasted. 41% of energy is wasted because of the second law of themodynamics. 43% of energy is wasted in the U.S. unnecessarily.
What are (a) a wind turbine and (b) a wind farm? List the advantages and disadvantages of using wind to produce electricity.
A.) Wind turbin are greater heating of the earth at the equator than at the poles and the earth's rotation set up flows of air called wind. Indrect form of solar energy can be captured by wind turbines and converted into electrcity. B.) Wind farm are clusters of wind turbines to produce electricity. Advantages: Moderate to high net energy, High efficiency, moderate capital cost, low electricity cost(and falling), very low environmental impact, No CO2 emissions, quic construction, easily expanded, can be located at sea, and land below turbines can be used to grow crops or graze livestock. Disadvantages: steady winds needed, Backup systems needed when winds are low, high land use for wind farm, visual pollution, noise when located near populated areas, may interfere in flights of migratory birds and kill birds of prey.
List the advantages and disadvantages of using (a) hybrid-electric cars and (b) fuel-cell cars.
A.)Advantages: Powered by a battery and small internal combustion engine that recharges the battery. Availabel now and get fuel from regular filling stations. Disadvantages: People believe SUVs and trucks are safer than midsize automobiles. B.) Advantages: Fuel Cells running on hydrogen and producing little pollution. Disadvantages: Depends on building a new network of hydrogen filling stations,Expensive at first.
List the advantages and disadvantages of (a) burning solid biomass as a source of energy, (b) using ethanol as a vehicle fuel, and (c) using methanol as a vehicle fuel.
A.)Burning solid biomass as a source of energy Advantages Large potential supply in some areas, moderate costs, No net CO2 increase if harvested and burned sustainably, plantation can be located on semiarid land not needed for crops, plantation can help restore degraded lands, can make a use of agricultural,timber, and urban wastes. Disadvantages: Nonrenewableif harvested unsustainably, moderate to high environmental impact, CO2 emissions if harvested and burned unsustainably, low photosynthetic efficiency, soil erosion, water pollution, and loss of wildlife habitat, plantations coudl compete with cropland, often burned in inefficient and polluting open fires and stoves. B.)Ethanol Fuel Advantages: High octane, some reduction CO2 emissions, reduced CO emissions, Can be sold as gasohol, potentially renewable. Disadvantages: Large fuel tank needed, Lower driving range, net energy loss, much higher cost, corn supply limited, may compete with growing food on cropland, higher No emissions, corrosive, hard to start in cold weather. C.)Methanol Advantages: High Octane, some reduction in CO2 emissions, lower total air pollution(30-40%), can be made from natural gas, agricultural wastes, sewage sludge, and garbage, can be used to produce H2 for fuel cells Disadvantages: Large fuel tank needed, half the driving range, coores, metal, rubber, plastic, high CO2 emissions it made from coal, expensive to produce, hard to start in cold weather.
List the advantages and disadvantages of concentrating solar energy to produce high-temperature heat or electricity.
Advantage: Moderate net energy, moderate environmental impact, No CO2 emissions, Fast construction(1-2 years) and costs reduced with natural gas turbine backup. Disadvntage: Low efficiency, high costs, needs backup or storage system, need access to sun most of the time, highland use, and may disturbe desert areas.
List the advantages and disadvantages of producing hydrogen from water or organic compounds and using the hydrogen as a source of energy.
Advantages: Very high efficiency, Moderate net energy at accessible sites, Lower CO2 emissions than fossil fuels, Low cost a favorable sites, low land use, low land disturbance, moderate environmental impact Disadvantages: not found in nautre, energy is needed to produce fuel, negative net energy, CO2 emissions if produced from carbon-containing compounds, nonrenewable if generated by fossil fuels or neclear power, high costs( but may eventually come down), will tkae 25 to 50 years to phase in, short driving range for current fuel cell cars, no fuel distribution system in place, excessive H2 leaks may deplete ozone.
What is cogeneration, and how efficient is it compared with producing electricity by a conventional coal-burning or nuclear power plant?
Cogeneration is combined heat and power. The systems have an energy efficiency of 80-90% (compared 30-40% for coal-fired boilers and nuclear power plants) and emit two-thirds less CO2 per unit of energy produced than conventional coal-fired boilers do.
What is energy efficiency? What are nine advantages of improving energy efficiency?
Energy efficiency is a measure of the useful energy produced by an energy conversion device compared to the energy that ends up being converted to low-quality, essentially useless heat. Nine advantages of improving energy efficicency include:
What do most experts believe is the best way to save energy in transportation? Why isn't this being emphasized in the United States?
Experts believe the best way to save money and energy is to increase the fuel efficiency of motor vehicles. These are not being emphaiszed int he US because inflation -adjusted price of gasoline in US today is low, 2/3 of US consumers perfer SUV's, pickup trucks, minivans, and other large, inefficient vehicles, and the failure of elected officials to raise CAFE stards since 1985 becaues of opposition from automakers and oil companies.
What are the four most efficient ways to heat a house? What are the most efficient and least efficient ways to heat water for washing and bathing?
Four most efficient ways to heat a house include Super insulated house, geothermal heat pumps, passive solar (100% of heat), and passive solar(50% of heat) plus high-efficiency natural as furnace (50% of heat). Most efficient way to heat water for washing and bathing include Tankless instant water heater and LPG water heater. While natural gas and electric rsistance heaters are the least efficient.
What is geothermal energy? Describe three types of geothermal reservoirs. List the advantages and disadvantages of using geothermal energy to produce heat and electricity.
Geothermal energy consists of heat stored in soil, underground rocks, many fluids in the earth's mantle. Examples are volcanic rock, geysers, and hot springs. Advantages: very high efficienty, moderate net energy at accessible sites, lower CO2 emissions than fossil fuels, low cost at favorable sites, low land use, low land disturbance, moderate environmental impact. Disadvantags:Scarcity of suitable sites, Depleted if used too rapidly, CO2 emissions, moderate to high local air pollution, Noise and color (HS2), Cost too high expect at the most concentrated and accessible sources.
Distinguish among large-scale hydropower, small-scale hydropower, and pumped-storage hydropower systems. List the advantages and disadvantages of using hydropower plants to produce electricity.
Large-scale hydropower- (large damn built across a river to create a dam) Small-scale-( a low damn with now, or only a small reservoir) Pumped-storage hydropower-(surplus energy from a conventional power plant is used to upmp water from one reservoir to another at a higher elevation, released when energy is needed. Advantages: Moderate to high net energy, high efficicency(80%), large untapped potential, low-cost electricity, long life span, No CO2 emissions during operation in temperate areas, may provide flood control below dam, providees water for year-round irrigation of cropland,and reservoir is useful for fishing and recreation. Disadvantages: High construction costs, high environmental impact from flooding land to form a reservoir, High CO2, emissions from biomass decay in shallow tropical reservoirs, floods natural areas behind dam, converts land habitat, danger of collapse, uproots people, decreases fish harvest below dam, decreases flow of natural fertilizer (silt) to land below dam.
What is net energy efficiency and how can it be improved??
Net energy efficiency is a measure of how much useful energy we get from an energy resource after subtracting the energy used and wasted in making the energy available. It can be improved by producing both heat and electricity from an energy source and by using energy-efficient electric motors and lightning.
Distinguish between a passive solar heating system and an active solar heating system, and list the advantages and disadvantages of these systems for heating buildings.
Passive solar heating system- system abosrbs and stores heat from the sun directly within a structure.. Active solar heating system- absorbs energy from the sun by pumping a heat-absorbing fluid through special collectors usually mounted ona roof or special racks to face the sun. Advantage: Energy is free, net energy is moderate to high, quick installation, No CO2 emissions, very low air and water pollution, very low land distrubance(built into roof or window) and moderate cost(passive). Disadvantages: Need access to sun 60% of time, blockage of sun access by other structures, need heat storage system,highcost(active) active system needs maintenance and repair, and active collectors unattractive
What is a solar cell? List the advantages and disadvantages of using solar cells to produce electricity.
Solar cell is a tranparent wafer containg a semiconductor material. Advantages: Fairly high net energy, work on cloudy days, quick installation, easily expanded or moved, No CO2 emissions, low environmental impact, last 20-40 years, low land use(if on roof or built into walls or windows), Reduces dependence on fossil fuels. Disadvantages: Need access to sun, low efficiency, need electricity storage system or backup, high land use( solar- cell power plants) could disrupt desert areas, high costs ( but should be competitve in 5-15 years), DC current must be converted to AC.
List ten things you can do to reduce your use and waste of energy.
Ten things I can do to reduce my use and waste of energy is to : -drive a car that gets at least 15 kilograms per liter and join a carpool -use mass transit, walking, and bicycling. -superinsulate your house and plug all air leaks. -turn off lights, TV sets, computers, and other electronic equipment when they are not in use. -Wash laundry in warm or cold water. -Use passive solar heating. -For cooling, open windows and use ceiling fans or whole-house attic or window fans. -Turns thermostats down in winter and up in summer. -Buy the most energy- efficient homes, lights, cars, and appliances availabe. -Turn down the thermostat on water heaters to 43-49 degrees C(110-220degreees F) and insulate hot water heaters and pipes.
Describe the coming energy efficiency and renewable energy revolution.
The coming energy efficiency will be used by 45 people getting 99% of its space and water heating and 95% of its daylight lighting from the sun. It uses 1/10 the usual amount of electricity for a structure its size. The revolution of new energy sources includes an advancement and wider use of solar cells that convert sunlight directly into electricity, and a hydrogen revolution. Energy efficient fuel cells could use hydrogen to produce electricity to run cars and appliances, heat water, and heat and cool buildings. Burning hydrogen creates produces water vapor and no CO2.
Explain why the real cost of gasoline to consumers in the United States is several times the price they pay at the pump.
The real cost of gasoline to consumers in the US is several times the price they pay at the pump because hidden costs really pay for Government subsidies and tax breaks for oil comapnies and roads, pollution clean up, Military protection of oil supplies in the Middle East, and Environmental, health, and social costs such as increased medical bills &insurance premums, time wasted in traffic jams, noise pollution, etc.
What are three important ways to save energy in houses and other buildings?
Three important ways to save energy in houses and other buildings is getting heat from the sun, super insulating them, and using plant-covered ecoroofs.
List two reasons why there is little emphasis on saving energy in the United States, despite its important benefits.
Two reasons why there is little emphasis on saving energy in the US is becaue low-cost(artificially) oil and gasoline and Lac of sufficient government tax breaks and other economic incentives for consumers and businesses to invest in improving energy efficicency.
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