Chapter 13: Achieving Energy Sustainability

Iceland produces how much of its energy through geothermal? In US? Why does it have less growth potential than wind or solar? Drawback of geothermal energy?

-25% -1% -not easily accessible everywhere -hazardous gases and steam can also escape from geothermal power plants

Biomass accounts for roughly ___% of renewable energy and approximately _____% of all energy consumed in the USA. How does mix of biomass used in the USA differ from developing countries?

-50; 4.5 -less than half of biomass in US is from wood, and similar amount comes from biofiels, with only 5% from MSW; in developing world, larger percentage of biomass energy comes from wood and animal manure

Efficiency of hydrogen fuel cells? By product produced? Therefore, do some policy makers believe it to be the future of energy?

-80% -water -yes

What fact about semiconductors is utilized in the generation of electricity by photovoltaic systems (PV)? What is the low voltage direct current converted into for use in home or businesses? Efficiency of PV in converting sunlight into energy?

-certain semiconductors (very thin ultraclean layers of material) generate a low voltage electric current when they are exposed to direct sunlight -higher voltage alternating current -12 to 20%

What two elements must a truly sustainable approach to energy use incorporate? What aspects do they have that allow us to maximize our energy resources? In many cases, why are they one of the easiest appoaches to implement?

-energy conservation and energy efficiency -least expensive, most environmentally sound -require fairly simple changes to existing systems rather than a complete switch to a new technology

As fossil fuels become less available and more expensive, what will likely take their place? Sources of energy other than fossil fuels that can be regenerated quickly (potentially renewable)? Sources that cannot be depleted no matter what (nondepletable)? Together what are these resources called?

-energy efficiency strategies, energy conservation, new energy sources -biomass, wood, biofuel -wind, solar, hydroelectric, geothermal -renewable resources

How is it possible to address the issue of the alteration of river ecosystem dynamics due to water impoundment (dams)? How can the issue of siltation be solved?

-fish ladders (but not all fish species can use them and sometimes predators monitor them for prey) -dredging, removal of sediment with heavy machinery that uses many fossil fuels

How do tidal energy systems capture kinetic energy of water flowing through estuaries ,rivers and bays and convert energy into electricity? Does tidal energy have potential to become a major energy source? Why or why not? What might the necessary construction of transmission lines on or near a coastline or estuary do to the surrounding environment?

-gates and turbines similar to those in run of the river and water impoundment systems -no, difference in water level between high and low tides is not enough to provide sufficient kinetic energy or generate large amount of electricity -disruptive effect on coastal, shoreline, or marine ecology and tourism

Although renewable energy is more sustainable than nonrenewable energy, using any form of energy does what to the environment? Best approach to minimize consequences? `Can any single energy source that we are currently aware of replace nonrenewable ones in a way that is completely nonpolluting, completely renewable, and free of environmental impacts?

-has an impact on the environment -minimizing energy use through conservation and efficiency, later making energy choices wisely depending on environmental, economic, and convenience factors -no

What do ground source heat pumps take advantage of in terms of energy produced by earth? Does Earth's temp about 3 m below the ground stay constant all year? Why? Though it is referred to as geothermal, what does this energy really come from?

-high thermal mass of ground -yes, ground retains Sun's heat more effectively than ambient air -solar energy

How can consumers increase energy efficiency through the products that they choose?Another way that consumers can increase energy efficiency?

-increased technology with increased efficiency; Compact fluorescent light bulbs use 1/4 energy of incandescent, and LED bulbs use 1/6 -switching to products that meet efficiency standards of the Energy Star program set by the US environmental protection agency

What is concentrating solar thermal (CST) systems? How do they produce electricity? Why do they have to be constructed in deserts? Why are they now just becoming more common, although they have existed for 10 years or more? Drawbacks to these plants?

-large applications of soar energy to electricity generation -lenses or mirrors and tracking systems to focus sunlight falling on a large area into small beam, heat of beam used to evaporate water and produce steam that turns a turbine to generate electricity -arrays of lenses and mirrors required are large -no se -large amount of land required, inability to generate at night

How can dam operators influence the amount of electricity produced with a water impoundment (hydroelectric) system? Why is this the most common type of hydroelectricity? Largest dam in the world?

-managing opening and closing of gates, they can control flow rate of water that turns turbine (and generator) -allows for generation of electricity on demand -Three Gorges Dam on Yangtze River in China

What does increasing energy efficiency mean for work and energy? Is energy efficiency closely related to energy conservation? Ways that one can conserve energy that show this?

-obtaining same work from a smaller amount of energy -yes -energy can be conserved by no using an electrical appliance (resulting in less energy consumption), or using a more efficient appliance (same work for more energy)

What did humans use before fossil fuels? What do people in developing countries primarily use? Renewable energy accounts for what percent of energy worldwide? US?

-renewable energy sources -biomass -14 -10

For what population do major hydroelectric dam projects bring renewable energy to? What is the most expensive part (and worst for the environment) of hydroelectric power? What are the benefits of water impoundment hydroelectric systems?

-rural residents in many countries -building the dam -generate lots of electricity without pollution or waste products; electricity is less expensive for consumer; reservoir behind a dam can provide recreational and economic opportunities and a downstream flood control for flood prone areas

What does demand for energy vary with? What may occur when electricity generating plants are unable to handle demand during high use periods? To avoid this, electricity companies must be able to provide enough energy to satisfy? Is this substantially over the average demand; what effects does it have as a result? To meet this, what do many electrical companies have to do?

-season, weather, time of day -brownouts, blackouts -peak demand -yes, substantially more energy than average energy amounts must be provided -keep backup generators of electricity available

Benefits of active solar energy systems (think environmental, economic, etc)

1. generating hot wter or electricity without producing CO2 or polluting air or water 2. CST and PV cells produce electricity on hot sunny days when demand for electricity is highest; reduce need for fossil fuel plants 3. small scale PV systems are cheaper, less expensive than installing electrical transmission lines to home site 4. On grid houses take about 5-20 years for payback, but once initial cost is paid back, electricity generated is almost free

Advantages wind power offers over other energy sources? (name at least 3)

1. nondepletable, clean, free energy resource 2. Once a wind turbine has been manufactured, wind is only significant input, and only fossil fuels required is fuel workers travelling to farm to maintain equipment 3.no pollution and no greenhouse gases 4. wind farms can share land with other uses unlike other forms of renewable energy

Drawbacks of active solar energy systems that have inhibited growth of solar energy use in US? (name at least 3)

1.PV cells are expensive to manufacture and install; initial cost is daunting and has long payback period, even with improved technology 2.manufacturing PV cells requires much energy, water, and involves a variety of toxic metals and industrial chemicals that can be released into environment during manufacturing process 3. For systems with batteries for energy storage, there are environmental effects of manufacturing, disposing of, or recycling batteries, and energy losses during charging, storage, recovery of electricity in batteries 4. End of life recycling of PV cells

tiered rate system

A billing system used by some electric companies in which customers pay higher rates as their use goes up

photovoltaic solar cells

A system of capturing energy from sunlight and converting it directly into electricity

ground source heat pump

A technology that transfers heat from the ground to a building

wind turbine

A turbine that converts wind energy into electricity

Hot water heat pump

A variation of the ground source heat pump, extracts heat from air in garage or basement and transfers it to water in domestic water tank to be used for household activities

Ethanol

Alcohol made by converting starches and sugars from plant material into alcohol and CO2.

fuel cell

An electrical-chemical device that converts fuel, such as hydrogen, into an electrical current.

nondepletable

An energy source that cannot be used up

water impoundment

the storage of water in a reservoir behind a dam

renewable

In energy management, an energy source that is either potentially renewable or nondepletable

Concentrating solar thermal (CST) systems

Large-scale applications of solar energy to electricity generation; use lenses or mirrors and tracking systems to focus the sunlight falling on a large area into a small beam

carbon neutral

an activity that does not change atmospheric CO2 concentrations

smart grid

an efficient, self-regulating electricity distribution network that accepts any source of electricity and distributes it automatically to end users

potentially renewable

an energy source that can be regenerated indefinitely as long as it is not overharvested

Geothermal energy

Heat energy that comes from the natural radioactive decay of elements deep within Earth

biofuel

Liquid fuel created from processed or refined biomass

siltation

The accumulation of sediments, primarily silt, on the bottom of a reservoir.

flow rate

The amount of fluid that flows past a point in a given amount of time (hydroelectric power)

electrolysis

The application of an electric current to water molecules to split them into hydrogen and oxygen

World's first and second leaders in ethanol production (and what each country makes ethanol from)? What factors in using sugar cane for ethanol production make it produce less fossil fuels? In which ratio is ethanol typically mixed with gasoline? What is the result called? In certain parts of midwestern US, what ethanol mix is made?

-US (corn), Brazil (sugar cane) -replanted every 6 yrs (compared to 1 for corn), sometimes harvested by hand -1 part ethanol to 9 parts gasoline (results in more oxygen, producing less air pollutants when combusted) -gasohol -E-85 (85% ethanol, 15% gasoline)

When can tree removal be sustainable? What other positive effect s might it have if in heavily forested areas, trees of a common species are removed? More often, what problems does tree removal cause?

-allow time for forests to regrow -allows other plants to grow and increase habitat diversity, which can increase total photosynthesis -soil erosion, increase water temps in nearby rivers and streams, fragment forest habitats when logging roads divide them -harming species dependent on old growth forest habitat

How can solar panels be used to supply electricity? The vast majority of PV systems are tied to electrical grid, meaning what for customers? What occurs to homes that are "off the grid"? Other uses of PV cells in locations far from the grid where small amount of electricity is needed on a regular basis?

-appliances or lights directly, or used to charge batteries -extra electricity generated and not needed is sent to electric utility which buys it or gives customer credit toward cost of future electricity use -use batteries to store electricity not needed -charging batteries keeping highway emergency telephones working, electricity for streetside trash compactors and "smart" parking meter systems

Which is more expensive, biodiesel or petroleum based diesel fuel? What is biodiesel typically diluted to with petroleum diesel? Can it be used in any diesel engine without modification? Why do higher concentrations of biodiesel only work for modified engines?

-biodiesel, but it depends -"B-20", or 20% biodiesel and 80% petroleum diesel -yes! -biodiesel tends to solidify into a gel at lower temperatures

Like fossil fuels, biomass contains a great deal of _________, and burning it releases that ________ into the atmosphere. Given the fact that both raise carbon concentrations, is it really better for environment to replace fossil fuels with biomass? How does carbon in biofuels differ from carbon in fossil fuels?

-carbon -This depends on how material is harvested, processed, how land is treated before and after harvest, and how long carbon has been stored -carbon found in plants growing today was recently in form of CO2 before it was incorporated into plants through photosynthesis, this could have occurred very recently or a few hundred years ago, while carbon in fossil fuels has been there for many years

Many people in developing world use wood to make which superior fuel? How is this better than wood? What are its two major faults? Where is it primarily used?

-charcoal! -lighter than wood, twice as much energy per unit of weight, produces less smoke than wood and does not need to be tended constantly like wood -more expensive than wood, harvesters who clear an area of land for charcoal production often leave it devoid of trees -urban areas of developing world and people who can afford it

What must a sustainable energy strategy do, since a single energy source cannot take over the role of nonrenewable resources with no ill effects? Important factors? What other considerations are important?

-combine energy efficiency, energy conservation, and development of renewable and nonrenewable energy resources, taking into account costs, benefits, and limitations of each -convenience and reliability -logistical considerations, such as where a source is located and how it is transported

Common appliance that operates like a fuel cell? Important difference? Chemical equation that displays how electricity is generated using a fuel cell? How does the basic process of a fuel cell produce an electric current?

-common battery -in a battery, no additional materials are added, so eventually reactants are used up and battery dies, but in a fuel cell, reactants are added constantly to cell, so it produces energy as long as it has fuel -2H2 + O2 -> energy + 2H20 -protons from hydrogen gas through a membrane while electrons take a different pathway; opposite movement creates an electric current

How is geothermal energy obtained? Three largest geothermal energy producers? Geothermal energy can be used directly as a source of what? How can it be used directly this way? How does Iceland heat its homes (another way to obtain geothermal energy and use it directly)?

-convection currents bring hot magma to source of earth, magma comes too close to groundwater and groundwater is heated, pressure of hot groundwater sometimes drives it to surface or it can be obtained by drilling -US, China, Iceland -heat energy -hot groundwater piped directly into household radiators to heat a home -heat exchangers can collect heat by circulating cool liquid underground, where heat from ground flows to cool circulating liquid then surface

Disadvantages of ethanol relating to car mileage? How does growing material for ethanol production become an advantage? What concern has this lead to for economic analysts? Furthermore, what issue do other scientists have with it?

-decreases mileage since it is less energy dense, 90/10 mix reduces mileage by 2-3% -growing corn uses a significant amount of fossil fuel energy, as well as land that could be devoted to growing food -production periodically contributes to short term food shortages -actually causes a net increase in atmospheric CO2 concentrations

Geothermal energy can be used to generate heat energy and....? What is the process in generating this type of energy? If used unsustainable, why might geothermal energy become nonrenewable? One way to use geothermal energy sustainably?

-electricity! -similar to conventional thermal power plant, except steam comes from water evaporated by Earth's internal heat -heat released by decaying radioactive elements is essentially nondepletable, but groundwater taken up to obtain heat is depletable -returning water to the ground to be reheated

Why is supplying hydrogen for a hydrogen fuel cell difficult? Currently, what two major processes are used to produce hydrogen?

-free hydrogen gas is rare in nature and explosive, tends to bond with other molecules and producing gas requires separating it using heat or electricity -energy intensive process of burning natural gas to extract hydrogen (CO2 is a waste product); electrolysis; energy scientists are currently looking for other solutions

What can liquid biofuels, ethanol and biodiesel, be used to replace (in order)? What can ethanol be produced by? How is biodiesel typically produced? Why are US policy makers encouraging the production of ethanol and biodiesel?

-gasoline, diesel -corn and corn by products (90%), sugar cane, wood chips, crop waste, switchgrass -extracting oil from algae and plants like soybean and palm -reduce imported oil, supporting US farmers and declining rural economies

How do household solar water heating systems work? What occurs in the simplest sola rwater heating systems after cold water has been pumped directly to collector to be heated? In areas that are sunny but experience temperatures below freezing, where is the water kept and what is done to keep it warm? What do solar water heating systems often include so that hot water is available even if it is cloudy and very cold?

-heat energy from sun to be transferred directly to water or other fluid, circulation is driven by pump (active systems) or convection (passive); cold liquid is heated as it moves through a solar collector mounted on roof or wall of building or situated on the ground -heated water flows back to insulated storage tank -water is kept in storage tank; "working" liquid containing nontoxic antifreeze circulates in pipes between storage tank and solar collector, liquid is heated by Sun in solar collector then returned to storage tank where it flows through a heat exchanger transferring heat to water -backup energy source

What is wood used to fuel or create throughout the world? In theory, how is cutting trees sustainable? However, what do most individuals do, making it unsustainable, and what are the effects? Is CO2 released from burned wood balanced by photosynthetic carbon fixation that would occur with new tree growth? How could carbon be released from the soil in the logging process?

-heating cooking, pulp and paper industries, power plants, wood waste and byproducts for energy, etc -forest keeps up with forest removal -intensive cutting, allowing little chance for regrowth; deforestation, net removal of forest with burning of wood results in net increase in atmospheric CO2 -no -occurs with carbon that may have been stored in A or B soil horizons, logging equipment disrupts soil

Second most commonly used form of renewable energy in world/US and most important for electricity generation? How does a hydroelectric power plant essentially work to produce electricity? What does the amount of electricity that can be generated depend on? When it is generated by falling water as a source of energy, what does amount of electricity generated depend on?

-hydroelectric power -moving water contains kinetic energy, and power plant captures kinetic energy and uses it to turn a turbine (similar to steam), which transforms kinetic energy of water into electricity, which is exported to electrical grid -flow rate, vertical distance water falls, or both -vertical distance water falls (greater distance more potential energy and more electricity to generate), flow rate (higher flow rate, more kinetic energy present and more electricity generated)

Energy Expert, Amory Lovins, suggests that what has provided the driving force for moving from one technology to the next? Despite their tremendous potential, renewable energy resources are unlikely to replace fossil fuels immediately in near future, unless countries do what..? Will fossil fuel consumption continue to rise in the near future?

-innovation and technological advances -commit to supporting development and use through direct funding and financial incentives like tax cuts and consumer rebates -increase

What are the current requirements for wind turbines on land? What is the usual practice for land wind turbines? Is the number of wind farms increasing or decreasing in US/around the world? What is the most desirable location? Is the US ahead or behind of other countries in development of offshore wind?

-installed in rural locations and away from buildings and population centers, close to electrical transmission lines with enough capacity to transport electricity they generate to users, political and regulatory reasons and to facilitate servicing equipment -grouped together in wind farms or wind parks -increasing -near offshore coastal locations (capacity up to 50%), or offshore wind parks -behind

Examples of how sustainable designs can improve efficiencies of buildings and communities in which we work? In the location of houses? What purposes do buildings consume a lot of energy for? Many sustainable building strategies involve utilizing which design for buildings?

-insulating foundation around walls and basement floors, orienting house towards sun, planting shade trees in warm climates -building close to where residents live and work -cooling, heating, lighting -passive solar design

What does passive solar heating NOT rely on to supply heat? Examples of its applications? How do solar ovens in particular have positive environmental and social effects?

-intermediate pumps or technology -covering buildings with dark roofing to absorb heat, building homes into side of hill, solar ovens, etc -Use in place of firewood reduces deforestation, and in areas unsafe for travel, one does not have to leave relative safety of home for firewood

Advantage of hydrogen for use in fuel cells, though it may seem counterintuitive to produce it by using electricity and use it for electricity? How can renewable energy sources come into play to produce this hydrogen, that could potentially be a good solution?

-it can act as an energy carrier -renewable energy sources cannot produce electricity constantly, but electricity they produce can be used to produce hydrogen, which can be stored until needed

Passive solar design stabilizes indoor temperatures without..? How are windows utilized in this design? How do placing dark materials on exterior or roof contribute? Conversely, what do light colored materials do? In summer, when Sun is high in the sky for much of day, what feature is used to block out sunlight during hottest period?

-need for pumps or other mechanical devices -windows facing the sun , double paned windows (insulate house while still allowing solar radiation to warm house), carefully placed windows (allow maximum amount of light in building and reduce need for artificial lighting), window shades - absorb more solar energy, warming said house -reflects heat away from building, keeping it cooler -overhang roof

Do ground source heat pumps actually remove heat from the ground? How does a ground source heat pump work? How does its function differ in winter and summer? Can they be installed anywhere on earth? What percent less energy do they use than a standard furnace or air conditioner?

-no -cycles fluid through pipes buried underground -In winter, fluid absorbs heat underground, warmed fluid is compressed in heat pump to increase temp more, fluid allowed to expand causing it to cool and run through cycle again, picking up more heat from ground -In summer, fluid is cooled underground then pulls heat from house as it circulates resulting in a cooler house -yes -30 to 70%

Do run of the river systems store water in a reservoir? Advantages of these systems that reduce their environmental impact? However, they are generally __________ sized, and since they rely on ___________ _________ flows, electricity can be intermittent. Major deficits?

-no -relatively little flooding occurs upstream, changes in river flow are not disrupted -small, natural water -heavy spring runoff canot be stored and no electricity can be generated in hot, dry conditions when water is low

An important aspect of energy conservation is reduction of ________ ____________, which would make it less likely that electric companies would have to do what? One way of reducing peak demand using a pricing structure? Positives of this approach?

-peak demand; build excess generating capacity used only sporadically -customers pay less to use electricity when demand is lowest and more when demand is highest -establish a variable pricing structure, where customers pay less to use energy when demand is lowest and more when it is highest -evens out use of electricity, reducing burden on generating by utility and rewards consumer at same time

Why would switchgrass be a viable alternative to corn as the primary source for US ethanol production? However, why do corn and sugarcane produce ethanol more readily? In contrast what are materials like switchgrass and wood chips like? Have scientists found an efficient breakdown process for large scale production of ethanol from switchgrass?

-perrenial (farmers harvest without replanting, minimizing soil disturbance and erosion), not require as much fossil fuels to produce as corn -sugars are readily and rapidly converted into ethanol -composed primarily of cellulose, which must be broken down into sugars before it can be used in ethanol production -no

How does using recycled building materials contribute to energy conservation? Is it possible to achieve energy efficiency even in very large buildings? Examples of active technologies to reduce energy consumption?

-reduces need for new construction materials, reducing amount of energy needed to produce components of the building (ex: many buildings have recycled denim insulation in walls and ceilings and fly ash in foundation -yes -radiant heating system carrying warm water through tubes in floor (less energy than traditional heating system), solar panels, etc

What common techniques does the hot water heat pump use that are similar to other appliances? How does a hot water heat pump work? In a hot water heat pump, what percent of energy in electricity is transferred to the water? How does the heat pump have such a high efficiency?

-refrigerators, air conditioners, ground source heat pump -extracts heat from surrounding air in basement/garage and pumps it into a tank filled with water destined for kitchen sink or bathroom shower -200 to 250% of energy in electricity used to run it is transferred to water in tank -utilizes energy in electricity and also in surrounding air , meaning that amount of energy required to run pump plus energy extracted from air is greater than electrical energy used to run heat pump

An energy economy based on nondepeletable energy requires what? What are people focusing their attention on currently to solve this? Why? One solution currently being implemented? Problems with current electrical grid?

-reliable energy storage an affordable (at least effective and efficient) distribution networks -improving electrical grid to make it as efficient as possible, removing need for storage capacity -since we do not currently have a cost effective, reliable means of storing energy, we should not depend on intermittent sources such as wind and solar for above 20% of energy production since it could lead to risky instability in grid -smart grid -relies on a system of regional electricity generation plants, that puts greater demands on rest of system when it shuts down

Why is burning manure beneficial? However, what negative effects does it have? How are these negative effects exacerbated by burning manure indoors? What air pollutants are produced by biofeuls in general?

-removes harmful microorganisms from surrounding areas (reducing risk of disease transmission) -releases particulate matter and other pollutants causing a variety of respiratory illnesses, from emphysema to cancer -often occurs in poorly ventilated rooms in developing countries, responsible for 3 million deaths annually (WHO) -particulate matter, CO2, nitrogen oxides

What advanced technologies are used with active solar energy?Main applications of solar water heating?

-solar water heating, photovoltaic solar cells, large scale concentrating solar thermal systems for electricity generation -providing domestic hot water, heating swimming pools (most common in US), heating purposes for business and home

With a kit sold commercially, a skilled individual or automobile mechanic can modify any diesel vehicle to run on 100% what? Is there enough waste vegetable oil for this to significantly reduce fossil fuel consumption? In US, most biodiesel comes from...? Other sources with potential for producing biodiesel? Are emissions of CO and CO2 higher or lower than petroleum diesel? Is it carbon neutral? Explain.

-straight vegetable oil (SVO) as waste from restaurants and filtered as fuel -no, but it is a potential transition fuel -soybean oil or processed vegetable oil -wood/other forms of cellulose, algae(produces greatest yield per hectare and uses least amount of energy and fertilizer) -lower -yes, it should be, but some scientists question whether it really is

What do all fossil fuels and most renewable resources ultimately come from? What is included as biomass? Why does biomass account for more than 10% of energy use around the world? Why are biofuels used in limited quantities?

-the Sun -wood and charcoal, animal products and manure, plant remains, municipal soil waste (MSW), liquid fuels like ethanol and biodiesel -inexpensive and abundant -technological demands associated with use (harder to develop technology than to burn a piece of wood)

To reduce demand for heating at night and cooling during the day, what material can builders use? Examples? What are two other unconventional ways to provide insulation and reduce need for heating and cooling? What is a green roof? Where are they common? Benefits?

-those with high thermal mass -stone, concrete (NOT wood or glass) -building a house into the side of a hill; roofing a building with soil and plants (green roof) -European cities -cool and shade buildings and surrounding environment, improves overall air quality

Limitations of renewable energy as a replacement for fossil fuels?

-transmission of renewable energy over electrical distribution network -cost and storage of energy

In time, researchers will develop solutions to the problem of creating efficient energy storage systems, which may reduce the need for what?One simple and effective aproach to solve this issue? What other technologies have been improving rapidly and have increased research put into them? Best known company making advances in this area?

-transport electricity over long distances -use excess capacity during off peak hours to pump water upwill with electricity to a reservoir, then during hours of peak demand, operators can release water through a turbine to generate necessary electricity cleanly and efficiently -battery technology and hydrogen fuel cell technology -Tesla

What are winds the result of? How is the sun the source of all winds? How does it rank for its growth as use for electricity? Countries with largest wind generating capacity?

-unequal heating on surface of Earth by sun -solar radiation and ground surface heating drive air circulation -first, fastest growing source -China, US, Germany, India, Spain

Why does the burning of fossil carbon result in a rapid increase in atmospheric CO2 concentration? In theory, why should the burning of biomass (modern carbon) not result in an increase in atmospheric CO2? How can biomass not be carbon neutral (and this is why its status as carbon neutral has been debated by scientists)?

-unlocking or releasing stored carbon that was last in atmosphere millions of years ago -returning carbon to atmosphere where it has been recently, and if vegetation is allowed to grow back where biomass is harvested, new vegetation will take up about the amount of CO2 previously released into the atmosphere -it ends up releasing CO2 that would have otherwise remained in the soil

What does second law of thermodynamics tell us? In a typical thermal fossil fuel or nuclear plant, how much of energy consumed goes to final purpose (the rest is lost as waste/heat)? With this included, what is the amount of energy we save the sum of?

-whenever energy is converted from one form to another, some energy is lost as unusable heat -1/3 -energy that we did not use and energy that would have been lost converting that energy into the form which we would have used it (converting it to different form)

How does a wind turbine work? What capacity factor does it have under average wind conditions on land? In a year, how much electricity can it produce? What are capacity factors like for offshore wind turbines?

-wind turns blades of wind turbine, blades transfer energy to gear box, which transfers energy to generator, that generates electricity -25% -more than 4.4 million kw/hrs of electricity (supply 400+ homes) -35-50%

Why would using hydrogen fueled vehicles be a sustainable means of transportation? Efficiency of electric motors? Even if this is multiplied by the efficiency of the hydrogen as a fuel (80%) itself, would it still be more efficient than a modern combusting engine? Would it still be more efficient if natural gas rather than a renewable resource was used to produce the hydrogen? In the case of using renewable resources, is the energy source carbon neutral and pollution free?

-would use an electric motor -60% -YES, modern is only 20% efficient -yes! -yes!

Does the sun provide energy directly as well as indirectly? Amount of solar energy available in a place varies with...? Average amount of solar energy available varies..? Two types of solar energy capturing?

-yes -amount of cloudiness, time of day, season -geographically -passive and active solar heating

Has the cost of renewable energy been falling? Why (costs tend to decline as...)? In general, any technology that has been in widespread use has an advantage over the newer technology because...? What has been instrumental in lowering costs of solar and wind for consumers?

-yes -costs tend to decline as installed capacity grows since from making it and getting more experience, companies learn to produce it less expensively -it is familiar, and because the less expensive it is, more people will buy it leading to further reductions in price; state and federal subsidies and tax incentives also lower price of technology -tax credits and rebates

Can the government apply energy conservation measures? What is one such approach? What are two other actions that the government might take?Some electric companies will bill people using which system?

-yes, they can implement large scale energy conservation measures encouraging or even requiring individuals to adopt strategies or habits that use less energy -improve qualitiy of public transportation -facilitate energy conservation by taxing electricity, oil, and natural gas ; offer rebates or tax credits for retrofitting a home so it operates on less energy -tiered rate system

Negative consequences of water impoundment (Name at least 2)

1. free flowing river must be held back causing flooding of potential agricultural land and canyons or force people to relocate 2. unsuitable for organisms or recreational activities dependent on a free flowing river (human parasites become more common and in hotter more deoxygenized stiller waters not as many species can survive) 3. alter dynamics of river ecosystem downstream (remove natural features, affect life cycles of salmon, trout, etc) by controlling flow of river 4. Release of greenhouse gases to atmosphere during dam construction and after filling reservoir 5. Production of cement for dam construction, and release of methane from anaerobically decomposing plants and animals from the area that the dam usurped 6. Accumulation of sediments in reservoirs (siltation)

Disadvantages of wind generated electricity? (name at least 3)

1. most off grid residential wind energy systems rely on batteries to store electricity (expensive and difficult to dispose of) 2. death of birds by wind turbine blades , but new designs and movement of location away from migration routes is solving some of this 3. Small community who find appearances of wind farms objectionable 4. Annoying sounds 5. slowing of development due to construction of above ground electrical transmission lines, necessary to move electricity to large number of users

Disadvantages of hydrogen as a fuel (primarily for hydrogen fuel cells)? (name at least 3)

1. scientist must learn how to obtain hydrogen without expending more fossil fuel energy than would be saved 2. Suppliers need a distribution network to safely deliver hydrogen; it can be placed in liquid or gas forms, but probably gas, and tank for carrying it would be much larger and there is always the risk of tank rupture

biodiesel

A diesel substitute produced by extracting and chemically altering oil from plants

flex fuel vehicles

A vehicle that runs on either gasoline or gasoline/ethanol mixture (mainly E-85)

modern carbon

Carbon in biomass that was recently in the atmosphere

fossil carbon

Carbon in fossil fuels

passive solar design

Construction designed to take advantage of solar radiation without active technology

wind energy

Energy generated from the kinetic energy of moving air

Tidal energy

Energy that comes from the movement of water driven by the gravitational pull of the Moon.

run-of-the-river

Hydroelectricity generation in which water is retained behind a low dam or no dam

hydroelectricity

electricity generated by the kinetic energy of moving water

Active solar energy

energy captured from sunlight with advanced technologies

energy conservation

finding and implementing ways to use less energy

Progress on technologies to address energy cost and storage may accelerate with what incentives/events/issues? In the immediate future, we are more likely to move towards a sustainable energy mix if...? Other ways to spur conservation of energy? One such initiative like this?

government intervention, taxes on industries that emit carbon dioxide, or a market in which consumers are willing to pay more for technologies with minimal environmental impacts -nonrenewable energy (fossil fuel) becomes more expensive -initiatives that regulate energy mix itself (ex: encouraging that a certain fraction of energy be generated using renewable sources) -Regional Greenhouse Gas Initiative (RGGI) (nine eastern states reduced greenhouse gas emissions from electricity generation plants in past 10 years)