APES 16,17,18 Review

Energy Efficiency

The percentage of total energy input that does useful work in an energy conversion system.

Life Cycle Cost

The initial cost plus the lifetime operating cost.

Co-generation

The production of two useful forms of energy from the same fuel source.

Super-insulated Houses

Heavily insulated houses that are so airtight that heat from direct sunlight, appliances and human bodies warm them with little or no need for backup heating systems.

Strawbale Houses

Houses with walls consisting of compacted bales of certain types of straw covered with plaster.

passive solar heating system

captures sunlight directly within a home and converts it into low-temperature heat for space heating

active solar heating system

collectors absorb solar energy and a fan or a pump supplies part of a building's space-heating or water-heating needs

earth tubes

can be used for indoor cooling. At a depth of 3-6 meters the soil temperatures stay about 5-13 C all year long allowing cool partially dehumidified air to enter a house.

solar thermal systems

collect and transform radiant energy from the sun into high-temperature thermal energy (heat). Generally term to describe all solar power plants.

central receiver system/ power tower

huge arrays of computer-controlled mirrors called HELIOSTATS tract the sun and focus sunlight on a central heat-collection tower that then produces steam from a collection fluid then power

solar thermal plant or distributed receiver system

sunlight is focused on oil-filled pipes running through the middle of curved solar collectors; it creates high temperatures for industrial processes - producing steam to run turbines and produce electricity

parabolic dish collectors

a distributed receiver system (similar to a TV satellite dish) used instead of parabolic troughs to track the sun along two axes and focus the heat to a collection fluid that can then be used to create steam then power.

photovoltaic (PV) Cells

Commonly called solar cells; directly converts solar energy into electrical energy with boron-enriched silicon wafer.

large-scale hydropower project

A high dam is built across a large river to create a reservoir. Some of the water in the reservoir is allowed to flow through huge pipes at controlled rates, spinning turbines and producing electricity.

small-scale hydropower project

A low dam with no reservoir (or only a small one) is built across a small stream. Output in small systems can vary with seasonal changes in stream flow.

pumped-storage hydropower systems

Supply extra power mainly during times of peak electrical demand. During low demand, usually night, conventional power is used to bring water from lower lakes or reservoirs back to a higher elevation to be used again.

Ocean thermal energy conservation (OTEC)

In evaluating the use of the large temperature differences of tropical oceans for producing energy, this would be used with plants anchored to the bottom of tropical oceans in suitable sites.

Saline solar ponds

Usually located near inland saline seas or lakes in areas with ample sunlight; can produce electricity from heat stored in layers of increasing concentrations of salt.

freshwater solar ponds

Can be used to heat water and space. A shallow hole is dug and lined with concrete. As number of large plastic black bags, each filled with several centimeters of water, are placed in the hole and then covered in fiberglass insulation panels. The panels let sunlight in, but keep most of the heat stored in the water during the daytime from being lost in the atmosphere. When the water in the bags has reached its peak temperature in the afternoon, a computer turns on pumps to transfer hot water from the bags into large, insulated tanks for distribution.

biomass

organic matter in plants produced through photosynthesis.

biofuels

Created from many forms of biomass, organic matter can be burned directly or converted into gaseous or liquid forms that can then be used as fuels.

biogas

A mixture of 60% methane and 40% carbon dioxide, liquid ethanol and liquid methanol.

biogas digesters

holds anaerobic bacteria that convert organic plant and animal wastes into methane fuel for heating and cooking.

Ethanol

Can be made from sugar and grain crops by fermentation and distillation.

Gasohol

Gasoline mixed with 10-23% pure ethanol; can be burned in conventional gasoline engines and sold as super unleaded or ethanol-enriched gasoline.

Methanol

Made mostly from gas but can also be produced at a higher cost from wood, wood wastes, agricultural wastes, sewage sludge, garbage and coal.

biomass plantations

Where large numbers of fast-growing trees (especially cottonwoods, poplars, sycamores and leucaenas), shrubs, and water hyacinths are planted to be burned directly and converted into burnable gas, or fermented into a liquid alcohol fuel. Located on semi-arid land.

photovoltaic-photoelectrochemical cell

Uses sunlight to split water into hydrogen and oxygen at an efficiency of 12.4%.

fuel cell

A possibility to power a car in which hydrogen and oxygen gas combined to produce electrical current.

geothermal energy

heat transferred from the earth's underground concentrations of dry steam, wet steam, or hot water trapped in fractured or porous rock

dry steam

steam without water droplets

wet steam

mixture of steam and water droplets

hot dry-rock zones

molten rock that has penetrated the earth's crust heats subsurface rock to high temperatures

warm-rock reservoir deposits

low to moderate temperature; used to preheat water and run heat pumps

taxing energy

government-based approach to include harmful costs of using energy (user-pays) in the market prices

freebates

self-financing system - charges fees to purchasers of inefficient products and uses those funds to provide rebates to buyers of efficient technology

full cost pricing

environmental and health costs are included in the market price of energy

micropower systems

Systems of small-scale decentralized units that generate 1-10,000 kilowatts of electricity. Examples include microturbines, fuel cells, and household solar panels and solar roofs.

R value

A measure of insulation's capacity to resist winter heat loss and summer heat gain. The higher the number the greater its resistance to heat transfer.

low-E

Refers to windows with microscopically thin, virtually invisible, metal or metallic oxide layers that function to increase the R-value by suppressing radiative heat flow.

Troposphere

Innermost layer of the atmosphere. It contains about 75% of the mass of earth's air and extends about 17 kilometers (11 miles) above sea level.

Tropopause

transition boundary that limits mixing between the troposphere and upper zones

Stratosphere

The second layer, stretching 17-50 kilometers (11-31 miles) above the earth's surface.. Its lower portion contains enough ozone (O3) gas to filter out about 99% of the sun's harmful ultraviolet radiation.

Stratopause

boundary between stratosphere and mesosphere

Mesosphere

The third layer of the atmosphere that is not only the coldest layer, but also spans altitudes of roughly 48 kilometers to 80 kilometers (50 miles). Most asteroids break apart in this layer.

Thermosphere

The fourth layer of the atmosphere where altitude spans from 80 kilometers and 460 kilometers. Temperature increases as pressure increases

Greenhouse Effect

The process in which certain gases (carbon dioxide, methane, and water vapor) trap sunlight energy in the Troposphere as heat

Ozone Shield

stratospheric ozone layer that absorbs ultraviolet radiation

Global Warming

an increase in the average temperature of the earth's atmosphere (especially a sustained increase that causes climatic changes)

ozone depletion

When the concentration of the ozone is reduced in the stratosphere

Major classes of Air pollutants

Carbon oxides (CO, CO2) sulfuroxides (SO2, SO3), nitrogen oxides (NOx), volatile organic compounds (VOCs), suspended particulate matter (SPM), photochemical oxidants, radioactive substances, and hazardous air pollutants (HAPs)

Examples of VOCs

methane, propane, chlorofluorocarbons

Suspended particulate matter

Consists of tiny particles of dust, soot, asbestos, salts, and microscopic droplets of liquids such as sulfuric acid and pesticides

Photochemical oxidants

chemicals such as NO2, O2, PANs - they can react with (oxidize) certain compounds in the atmosphere that are usually not oxidized by reaction with oxygen

Examples of radioactive substances as air pollution

Radon-222, Iodine-131, Strontium-90, Plutonium-239, Cesium-137

Hazardous air pollutants (HAPs)

Air pollutants that are potentially harmful and may pose longterm health risks to people who live and work around chemical factories, incinerators, or other facilities that produce or use them. Considered to be especially dangerous air pollutants because they can cause cancer, birth defects, and nervous system problems

Examples of HAPs

Carbon tetrachloride, methyl chloride, chloroform, benzene, ethylene dibromide, formaldehyde

Primary pollutants

pollutants that are put directly into the air by human or natural activity.

Examples of primary pollutants

CO, CO2, SO2, NO, NO2, Most hydrocarbons, Most SPMs

secondary pollutants

pollutants that form from chemical reactions that occur when primary pollutants come in contact with other primary pollutants or with naturally occuring substances, such as water vapor.

Examples of secondary pollutants

SO3, HNO3, H2SO4, H2O2, O3, PANs

Photochemical reaction

Any chemical reaction activated by light

Photochemical smog

A mixture of primary and secondary pollutants formed under the influence of sunlight

Industrial Smog

Consists mostly of sulfur dioxide, suspended droplets of sulfuric acid (formed from some of the sulfur dioxide) and a variety of suspended solid particles and droplets.

Gray-air smog

Given its name because the tiny suspended particles of salt and carbon (soot) gives industrial smog a gray color.

subsidence temperature inversion

Inversion of normal air temperature layers when a large mass of warm air moves into a region at a high altitude and floats over a mass of colder air near the ground. This keeps the air over a city stagnant and prevents vertical mixing and dispersion of air pollutants.

radiation temperature inversion

Typically occurs at night in which a layer of warm air lies atop a layer of cooler air nearer the ground as the air near the ground cools faster than the air above it. As the sun rises and warms the earth's surface, the inversion normally disappears by noon and disperses the pollutants built up during the night.

Acid Deposition

Sulfur oxides and nitrogen oxides, emitted by burning fossil fuels, enter the atmosphere-where they combine with oxygen and water to form sulfuric acid and nitric acid-and return to Earth's surface

acid shock

The sudden runoff of large amounts of highly acidic water into lakes and streams when snow melts in the spring or when heavy rains follow a drought

Sick Building Syndrome

EPA studies have linked pollutants found in buildings to dizziness, headaches, coughing, sneezing, nausea, burning eyes, chronic fatigue, and flu-like symptoms. New buildings are more commonly "sick" than old buildings.

fiberglass

widespread and potentially potent carcinogen in indoor air

formaldehyde

extremely irritating gas; causes chronic breathing problems, dizziness, rash, headaches, sore throat, sinus and eye irritation, and nausea; caused by common building materials, furniture, drapes, upholstery and adhesives in carpets and wallpaper.

asbestos

refers to several different fibrous forms of silicate minerals; it is an incombustible mineral known to cause fibrosis and scarring in the lungs. Also a known carcinogenic material (lung cancer, mesothelioma)

asbestosis

a chronic, fatal disease that can make breathing impossible

mesothelioma

an inoperable cancer of the chest cavity

Radon-222

colorless, odorless, tasteless, naturally occurring radioactive gas that is produced by the radioactive decay of uranium--238 (found in soil, rock and underground deposits of phosphate, granite and shale); the recommended maximum level of exposure is 4 picocuries per liter of air

respiratory diseases

lung cancer, asthma, chronic bronchitis, emphysema

National Ambient Air Quality Standards (NAAQS)

Required by the Clean Air Act for the six criteria outdoor pollutants. (CO, NO2, SO2, SPM, O3, Pb)These 6 outdoor pollutants are regulated through a primary standard (to protect human health) and a secondary standard (to prevent environmental and property damage). Each standard specifies the maximum allowable level per period of time.

emission trading policy (cap and trade)

Each year a power plant is given a certain number of pollution credits or rights that allow it to emit a certain amount of SO2. A utility that emits less SO2 than its limits receives more pollution credits. It can use these credits to avoid reductions in emissions of its other facilities, bank them for future plant expansions, or sell them to other utilities.

electrostatic precipitator

A device used for removing particulates from smokestack emissions. The charged particles are attracted to an oppositely charged metal plate, where they are precipitated out of the air.

baghouse filter

an air pollution control device where particulates are removed by a series of filter bags that physically filter out the particles

cyclone separator

causes smoke stack gases to spiral upward through it in a circular motion, these particles hit the outer walls, settle out, and are collected at the bottom

wet scrubber

used to reduce particulates and SOx in smokestack emissions; fine mist is sprayed as emissions of particulates, soot and SOx pass by; fine mist traps particulates and soot and allows it to fall out of suspension and be collected; SOx passing through mist that has lime (CaO) or limestone (CaCO3) is converted to calcium sulfite (CaSO3) sludge that can be collected and disposed of

Greenhouse Effect

natural situation in which heat is retained in Earth's troposphere

Greenhouse Gases

Gases in the earth's lower atmosphere (troposphere) that cause the greenhouse effect. Examples are carbon dioxide, chlorofluorocarbons, ozone, methane, water vapor, and nitrous oxide.

Global Warming

gradual warming of the earth's average temperature and its atmosphere that may be caused in part by pollution and an increase in the greenhouse effect

General Circulation Models

complex mathematical models that use supercomputers to analyze and make quantitative predictions of future climate change

Climate Noise

the normal short-term ups-and-downs of the global temperature

Albedo

Ability of the earths surface (land, water, and ice) to reflect light.

Aerosols

tiny solid particles or liquid droplets that remain suspended in the atmosphere for a long time

Acid Rain

aerosols that are major components of acid decomposition. slows forest growth and weakness or kills many trees.

Forest Turnover

how fast trees grow and die in a forest.

Climate

the weather average over decades, centuries, and millennial.

Boiled Frog Syndrome

when global warming crosses the threshold and triggers obvious and serious effects on wildlife.

Carbon Taxes

A tax on fossil fuels (especially coal and gasoline) based on their emissions of CO2 and other air pollutants.

Polluter-Pays

Requires industries and consumers to pay directly for the full environmental costs if the fuels they use.

Technofixes

Technological solutions for dealing with possible global warming.

Ozone Layer

Stratospheric global sunscreen.

Freons

The trade name for CFC-11 (trichlorofluoromethane, CCl3F) and CFC-12 (dichlorofluoromethane, CCl3F). They are chemically stable, odorless, nonflammable, nontoxic and noncorrosive.

ODCs

All ozone depleting compounds are collectively called this.