Chapter 16 Flashcards
Renewable Energy Alternatives
Feed-in tariff system
utilities must buy electricity from anyone who can produce it from renewable sources
Green-collar jobs
jobs in design, installation, and maintenance for the shift to renewable energy
Solar energy
energy from the sun (enough is received each day to power human consumption for 25 years)
Passive solar energy collection
designing buildings to maximize sunlight absorption in winter and keep the interior cool in summer
Thermal mass
materials that absorb, store, and slowly release heat
Active solar energy collection
uses devices to focus/move/store solar energy
Flat plate solar collectors
dark, heat-absorbing metal plates in flat glass boxes that absorb solar heat from the roof and transfer it to hot water tanks inside
Concentrated solar power (CSP)
gathers solar energy from a large area and focuses it to a single point
Solar cookers
portable ovens that use reflectors to focus sunlight and cook food
Photovoltaic (PV) cells
convert sunlight to electrical energy by transferring electrons across silicon plates
Thin-film solar cells
variation of PV technology where photovoltaic materials are compressed into ultra-thin sheets, less efficient but cheaper
Net metering
value of excess power a consumer provides is subtracted from the monthly utility bill
Intermittent resource (solar power)
daily/seasonal variations in sunlight prevent a consistent energy supply without storage capacity
Wind power
generated by movement of air from differentially heated air masses
Wind turbines
convert mechanical energy of wind into electrical energy
Nacelle
holds machinery that rotates when wind turns rotor blades
Wind farm
group of turbines
Geothermal energy
thermal energy from beneath the Earth’s surface, which manifests itself in certain areas at the surface
Ground-source heat pumps (GSHPs)
transfer heat from the ground into buildings in winter, then back into the ground in summer
Enhanced geothermal systems (EGS)
pump cold water into dry underground rock, allow its heating, then draw it back up to generate power
Tidal energy
energy from large differences in height between high and low tide
Ocean thermal energy conversion (OTEC)
experimental approach that uses temperature gradient in the ocean (which absorbs much heat at the surface) to generate power
Hydroelectric power/hydropower
generates electricity by turning turbines with the kinetic energy of flowing river water
Storage technique
stores and releases water through turbines in a dam for hydroelectric power
Run-of-river technique
diverts some river water through a pipe/channel, passes it through a powerhouse, and returns it to the river for hydroelectric power
Pumped storage hydropower
transports water from a lower to a higher reservoir when demand for power is weak and prices are low; allows water to flow back downhill through a turbine when demand increases again
Bioenergy
energy derived from biomass
Biomass
organic material from living/recently living organisms, which contains chemical energy from sunlight and photosynthesis
Biopower
biomass used to generate electricity
Co-firing
wood chips/pellets are combined with coal
Gasification
power plants vaporize biomass at high temperatures to spin turbines
Pyrolysis
produces a liquid biopower fuel that can be burned to generate electricity
Biofuels
liquid fuels produced from biomass that power automobiles
Ethanol
produced by fermented biomass (typically carbohydrate-rich crops) in a process like brewing beer
Biodiesel
fuel from vegetable oil/used cooking grease/animal fat
Cellulosic ethanol
ethanol from cellulose, which is found in all plant material and has no food value, and can be produced rapidly from native plants
Fuel cells
use hydrogen as a stored power source
Electrolysis
process that uses electricity to split water molecules into hydrogen/oxygen gas molecules (2H2O –> 2H2 + O2)
