Energy Assignment Part 1

For EACH of the energy types that you research you should look at the pros and cons, how we use it, the benefits, drawbacks etc. Make sure that you are familiar with how they work. 

From the following list choose THREE: 
-Coal
-Nuclear
-Solar
-Tidal
-Wind
-Hydrothermal
-Geothermal

Nuclear Energy


 Nucleur energy comes from Uranium; a non renewable resource that must be mined. It is the energy released during nuclear fission or fusion, especially when used to generate electricty.
Fusion = energy released when atoms are combined or fused together to form a larger atom.
Fission = atoms split into smaller atoms, releasing energy.
*Nuclear Power Plants can only use nuclear fission to produce electricty.

How it works
heat to make the steam is created when uranium atoms split. Pressurized water reactors keep water under pressure so that it heats, but does not boil.

Pros
-lower carbon dioxide (and greenhouse gases) released into the atmosphere in power generation
-relatively low operating costs
-known, developed technology "ready" for market
-large power-generating capacity able to meet industrial and city needs
-existing and future nuclear waste can be reduced through waste recycling and reprocessing
-reliable
-cheap electricity
-this energy has a continuous supply and is widely available

Cons
-high construction costs due to complex radiation containment and procedures
-high subsidies needed for construction and operation, as well as loan guarantees
-subsidies and investment could be spent on other solutions (such as renewable energy systems)
-high-known risks in an accident
-unknown risks
-long construction time
-requires large infrastructure and investment
-waivers are required to limit liability of companies in the event of an accident
-waste lasts 200-500 thousand years
-radioactive waste
-nuclear radiation
-impact on aquatic life
-major impact on human life
-Uranium is scarce and exists only in a few places
-non renewable

Solar Energy



Energy harnessed from sun's radiant heat and light.

Solar Photovoltaics (PV) = system using panels composed of solar cells to supply usable solar power.Used primarily for grid-connected electricty. Can be ground-mounted, installed on building rooftops, or designed into building materials at the point of manufacturing

How it works
direct conversion of light into electricty at the atomic level. Absorbs photons of light and releases electrons. When free electrons are captured, electric current results can be used as electricty.

Pros
-clean energy. no combustion. no greenhouse emission from use
-inexhuastible and abundant "fuel" supply
-available nearly anywhere
-well suited for distribution generation
-technology exists today and is rapidly improving
-generates electricty directly from sunlight
-no moving parts required
-power generation is silent. no noise or pollution
-little or no transmission required
-matches well with air-conditioning need
-require minimal maintenance
-excess heat can be used for co-generation

Cons
-intermittent source. not available at night or under clouds
-relatively high cost, especially with storage
-requires inverter to produce AC current
-requires storage or grid connection for continuous round-the-clock use
-less available for heating demand (time of day, season)
-exotic materials required in many thin-film systems
-requires a relatively large amount of open space
-relatively low efficiency
-relatively low energy intensity
-fragile materials
-possible aesthetic issues

Tidal Energy



Form of hydropower that converts the energy of tides into useful forms of power; mainly electricty. Tidal energy is a predictable form of renewable energy, which can be harnessed by:

-Tidal Range: barrages or lagoons constructed to capture tide; turbines in lagoons/barrier generate electricity as tide floods into reservoir

-Tidal Stream: flow of water as tide ebbs and floods, manifests itself as tidal current. Devices seek to extract energy from kinetic movement of water

How it works
energy obtained from changing sea levels through tidal energy generators. These large underwater turbines are placed in areas with high tidal movements, designed to capture kinetic motion of ebbing and surging of ocean tides to produce electricity

Pros
-tides go in and out twice a day = reliable = easy to predict
-renewable
-produces no emissions
-requires no fuel
-high efficiency
-environmental impacts are local, not global
-effective at low speeds
-long life-spans
-low labor costs
-minimal visual impact
-consistent power

Cons
-upfront capital costs are very high as most of the schemes require massive concrete constructions
-tidal power stations only generate electricity when tide is flowing in or out (ten hours a day)
-widespread environmental and ecological damage to aquatic system
-equipment may be damaged by strong currents and freak waves
-non-continuous, storage or grid-backup required
-locations often remote
-can change tidal level of surrounding area
-barrages may restrict access to open water
-captures dirt, waste, and pollution near the coast
-decreases salinity in tidal basins
-reduces kinetic energy in ocean
-shifting tides
-reduced sea usage = shipping and recreation areas