APES Review 5 Energy Resources and Consumption

energy

Ability to do work

convection

Process by which, in a fluid being heated, the warmer part of the mass will rise and the cooler portions will sink.

conduction

Form of heat transfer where heat energy is directly transferred between molecules through molecular collisions or direct contact.

high quality energy

organized & concentrated; can perform useful work (fossil fuel & nuclear)

low quality energy

disorganized, dispersed (heat in ocean or air wind, solar)

power

the rate of doing work

power units

are watts and horsepower

turbine

machine that converts mechanical energy (wind, moving water, steam) into electrical energy by use of a generator

generator

A device that uses electromagnetic induction to induce electrical current by rotating loops of wire through a magnetic field

first law of thermodynamics

Energy can be transferred and transformed, but it cannot be created or destroyed.

second law of thermodynamics

when energy is changed from one form to another, some useful energy is always degraded into lower quality energy (usually heat)

fossil fuel

a nonrenewable energy resource formed from the remains of organisms that lived long ago; examples include oil, coal, and natural gas

coal seam

A layer of coal, usually 1 to 2 m thick.

natural gas

Fossil fuel consisting of methane that occurs naturally underground

methane

colorless, odorless, flammable gas present in natural gas and formed by the decomposition of organic matter; can be produced by living organisms

exploratory wells

used to drill and sample a particular area for fossil fuel deposits, can provide estimate the proven reserve

crude oil

petroleum as it comes out of the ground and before it has been refined or processed into useful products.

pressure extraction

when mud, saltwater, and CO2 are pumped into the ground to pressurize the oil so it comes to the surface

anthracite

the cleanest-burning coal; almost pure carbon.

underground mining

involves the sinking of shafts to reach underground deposits. In this type of mining, networks of tunnels are dug or blasted and humans enter these tunnels in order to manually retrieve the coal.

strip mining

a process in which rock and soil are stripped from the earths surface to expose the underlying materials to be mined

overburden

Overlying layers of soil and rock over mineral deposits. - Removed during surface mining

oil reserves

oil that has been discovered, but remains unused in the ground

shale oil

Slow-flowing, dark brown, heavy oil obtained when kerogen in oil shale is vaporized at high temperatures and then condensed. Can be refined to yield gasoline, heating oil, and other petroleum products

tar sands

Unconventional form of oil, liquid petroleum can be extracted with hot water, however not widely used because of the cost and environmental impacts.

electrostatic precipitators

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.

natural gas pros

ample supply, high net energy yield, low cost, low pollution emissions and environmental impact, easily transported, low land use, good fuel (fuel cells, gas turbines)

natural gas cons

Releases CO2 when burned, methane can leak- pipelines, shipped across oceans (Explosive LNG), burned off and wasted because of low price

coal pros

Ample supplies, high net energy yield, low cost

coal cons

highest environmental impact, severe land use and disturbance, severe land/air/water pollution, severe human health impacts, high CO2 and CH4 emissions, mercury and heavy metals, radioactive isotopes, SOX

petroleum pros and cons

cheap, easily transported, high-quality energy. Cons: reserves depleted soon, pollution during drilling, transport and refining, land subsidence, burning oil produces CO2

nuclear fission

Nuclear change in which the nuclei of certain isotopes with large mass numbers (such as uranium-235 and plutonium-239) are split apart into lighter nuclei when struck by a neutron. This process releases more neutrons and a large amount of energy.

parts of a nuclear reactor

core, control rods, moderator, steam, generator, turbine, containment building

nuclear power pros

(A) Large fuel supply

(B) Low environmental impact (without accidents) and emits 1/6 amount of CO2 as coal

(C) Less Land disruption

(D) Low risk of accidents

nuclear power cons

Waste product (spent fuels) and other radioactive waste difficult to store and contain; Must first be stored in pools to cool the fuel or in specialized dry storage; Water used in cooling process causes thermal pollution; Half life of uranium used for fuel is 704 million years; No long term storage yet; 9 year average between time of construction to operation

half life

length of time required for half of the radioactive atoms in a sample to decay

meltdown

Severe overheating of a nuclear reactor core, resulting in melting of the core and escape of radiation.

thermal pollution

a temperature increase in a body of water that is caused by human activity and that has a harmful effect on water quality and on the ability of that body of water to support life

nuclear accidents

Three mile Island (U.S.) had a meltdown occured through one half of one reactor core. Chernobyl (Ukrain) was worst, with an explosion that destroyed the reactor and sent clouds of radioactive debris into the atmosphere. Recent example Fukushima, Japan with earthquake and tsunami leading to meltdown and explosions.

radioactive waste

Particles from a nuclear reaction that emit radiation; contact with such particles may be harmful or lethal to people and must therefore be safely stored for thousands of years.

Yucca Mountain

in Nevada as a permanent storage site for high-level radioactive wastes from commercially operated nuclear power plants

nuclear fusion

2 isotopes of light elements (H) forced together at high temperatures till they fuse to form a heavier nucleus. Happens in the Sun, very difficult to accomplish on Earth, prohibitively expensive.

hydroelectric

pertaining to the generation and distribution of electricity derived from the energy of falling water or any other hydraulic source

hydroelectric pros

renewable

electricity with no pollution

no mining

easy to make and cheap after dam is built

fish ladders

A stair-like structure that allows migrating fish to get around a dam.

issues with dams

Change rivers (Nile) , canyons, wildlife. Limited lifespan (50-75 years) because of silting (build up of sediment behind dam). Displacement of population from reservoir behind dam

hybrid vehicle

A vehicle that uses both an electric motor and internal combustion engine for propulsion. This type of vehicle gets

better gas mileage and has lower emissions than conventional

vehicles.

mass transit

solution to an urban problem; methods of moving large numbers of people. Ex: Buses, subway

passive solar

Features of ______ designs are adobe walls used for heat storage, windows on the south side of the house, summer cooling vents on the roof, and flagstone floor used for heat storage.

active solar

A method of capturing the sun's energy and distributing it using pumps and fans.

photovoltaic cell

solar energy cells, usually made from silicon, that collect solar rays to generate electricity

hydrogen fuel cells

combines hydrogen gas and oxygen gas fuel to produce electricity and water vapor. Fuel efficient, reduce fossil fuel use if hydrogen isn't extracted from one.

biomass

plant materials and animal waste used as fuel; wood, charcoal, animal waste

ethanol

a fuel made from corn and wheat that is used like gasoline but is a renewable resource

biodiesel

A diesel-equivalent, processed fuel derived from biological sources (such as vegetable oils), that can be used in unmodified diesel-engine vehicles.

wind turbine

A propeller driven by the wind and connected to a generator. The wind makes it turn the generator, which produces electricity.

wind energy pros

Clean emissions

Free energy source

Affordable power

tidal energy

energy produced by the rise and fall of ocean levels; used to generate electricity

geothermal

A resource uses the earths thermal energy to heat water and uses the steam to turn a generator to produce electric energy.

fracking

The pumping of water at high pressure to break apart rocks in order to release natural gas