Energy Resources Flashcards
renewable energy source definition
aresourcewhich can be used repeatedly and replaced naturally
renewable energy source examples (name 4)
Solar origin (wind and hydropower), forests (trees), geothermal energy, hydroelectric power (dams), tidal power •Nuclear fuels can be characterized as both renewable and nonrenewable depending on how they’re used
non renewable energy source definition
aresourceof economic value that cannot be readily replaced by natural means on a level equal to its consumption; their use is not sustainable because their formation takes billions of years
non renewable energy source example
- Fossil fuels (coal, oil, natural gas and certain metals)
define geothermal energy and its advantages
• heat from earth is used. Steam comes from beneath earth’s surface which can be harnessed by several techniques and can generate electricity
- Dry steam geothermal power plant- underground steam flows into turbine to drive generator which produces electricity
- Binary cycle plant
- Advantages= low emissions, small physical footprint, minimal environmental impact, recycle wastewater
define fuel cell energy and its uses
• Generates electricity from hydrogen and oxygen—exhausts nothing but water (because hydrogen combines with oxygen)
- Provide critical energy backup for many large facilities, and they provide primary energy for some remote locations. Fuel cells are even being used to power vehicles and homes. Individual fuel cells can be stacked to provide more power, taller stack = more power it generates
define solar energy
• energyfrom the sun that is converted into thermal or electricalenergy
- Solar panels, has no emissions, doesn’t make noise, doesn’t need water or fossil fuels to produce power
how is solar energy converted? (4 ways)
- Parabolic solar trough- most widely applied approach- uses lenses or mirrors that condense large area of sun into a small beam, beam is directed onto tube that is heated. Fluid enters heat exchanger and boils water, creating steam and pressure that is passed thru turbine to generate electricity. 2. Power towers- advanced version of parabolic solar trough. 3. The Stirling engine- used in many developing countries. 4. Methane production- anaerobic digestion of animal and plant wastes in municipal sanitary landfills yields methane as a byproduct- systems collect methane which is used to generate heat and electricity
Biofuels definition
• can create clean, renewable transportation fuels from plants, trees, and a range of other organic materials — in other words, biomass.
- Biomass is an organic renewable energy source that includes materials such as agriculture and forest residues, energy crops, and algae. Scientists and engineers at the U.S. Department of Energy and its national laboratories are finding new, more efficient ways to convert biomass into biofuels that can take the place of conventional fuels like gasoline, diesel, and jet fuel
bioenergy definition (what organism?)
algae, or more correctly, microalgae, are very small aquatic organisms that convert sunlight into energy. Some of these algae store energy in the form of natural oils. Under the right conditions, algae can make a lot of oil that can be converted into biofuels
marine and hydrokinetic energy definition
movement of the ocean’s waves, tides, and currents carries energy that can be harnessed and converted into electricity to power our homes, buildings and cities
hydroelectric power definition
water flows from a higher elevation to a lower elevation, and a hydropower facility uses turbines and generators to convert this motion into electricity, largest source of renewable power
wind power definition
• use of air flow through wind turbines to mechanically power generators for electric power
how does a wind turbine work?
- a wind turbine blade works sort of like an airplane wing. Blowing air passes around both sides of the blade. The shape of the blade causes the air pressure to be uneven – higher on one side of the blade and lower on the other. And that’s what makes it spin… the uneven pressure causes the blades to spin around the center of the turbine
advantages of geothermal energy
- good for environment- no emissions
- reliable- constant source of energy and is available all year long
- uses less electricity
disadvantages of geothermal energy
- withdrawal of water can lead to subsidence, accidental spillage can lead to increased salinity of soil and pollution of surface waters, problems with release of radon and volatile gases (which accompany the steam)
- land requirements for geothermal system to be installed
advantages of solar energy
- doesn’t need water or fossil fuels to produce power
- can be harnessed in all areas of world and is available mostly every day, will not run out of it
- reduces electricity bills
- low maintenance costs- only clean a few times/year
disadvantages of solar energy
- solar energy is that infrastructure would cost much more than continuing to burn fossil fuels (initial cost of purchasing solar system is high)
- weather dependent
- solar energy storage (in batteries) is expensive
- uses a lot of space more energy want to produce = more solar panels installed
advantages of hydroelectric power
- renewable
- doesn’t pollute
- reliable
- flexible – adjusting water flow and output of electricity is easy
- safe (no fuel involved, besides water)
- dams in particular = Allows large numbers of people to inhabit previously uninhabitable regions and protects plains from periodic flooding, and permits construction of cities that otherwise couldn’t exist
disadvantages of hydroelectric power
- environmental consequences= Alters environment for aquatic life and the lives of people, can alter the way nutrients and minerals travel (leading to decrease in farming in some areas and fishing), displaces many people who live near the site, construction brought up salts from the ground making it less usable for agriculture, increase growth of algae and phytoplankton, erosion caused landslides
- expensive
- if drought occurred, it could affect this source
advantages of wind power
- unlimited, free, renewable
- doesn’t pollute
- cost of wind power is about one-quarter of that for electricity generated using natural gas
- costs are steady and do not fluctuate
disadvantages of wind power
- blades on wind towers produce noise
- interfere with TV reception
- harm birds
- initial cost
- aesthetic impact (visual effects on nature and scenery)