Energising Alternatives!

We have spent the last two weeks studying the mechanisms behind the greenhouse effect, and also the enhanced greenhouse effect. Remember that the greenhouse effect is a natural part of Earth’s atmosphere – it helps capture heat from the Sun, and means that Earth’s climate is suitable for human life.

You need to understand that the reason that the Earth’s is habitable is that it is at a very special distance from our Sun. The Energy that our Sun gives off provides enough heat at the distance that the Earth orbits to keep water liquid. If we were much closer, water would boil into steam (like Mercury or Venus), and if we were much futher away, water would freeze into ice (like Mars or the other outer planets). This is the so-called “Habitable Zone” (or sometimes the “Goldilocks Zone” – because it is not too hot, not too cold, it’s just right) of our Sun. Earth is on the outer edge of this zone, and so the natural ability of the Earth’s atmosphere to store heat keeps the Earth environment survivable. (If you want to know more about this, try these links: 1, 2, 3, 4)

This Habitable Zone depends on a lot of things, but especially on our Sun. if it was bigger or smaller, hotter or colder, younger or older, the distance at which a planet would be in the habitable zone changes – the diagram to the right shows how this changes. But the sun is not the only factor – the Earth’s Greenhouse effect is also part of what keeps the Earth warm.

This is why we study the Greenhouse Effect, and particularly the enhanced greenhouse effect.

To enhance something means to increase it’s effect – so the enhanced greenhouse effect is like the greenhouse effect, but stronger. Remember the basic ideas behind the greenhouse effect is that certain gases (like water vapor, methane and carbon dioxide) allow the Earth’s atmosphere to trap heat. The enhanced greenhouse effect is due to increased amounts of these greenhouse gases in the atmosphere, particularly carbon dioxide.

A lot of scientists (particularly “climatologists”) are concerned that the increased effects of the enhanced greenhouse effect may cause the climate to change – to become much hotter or colder. This has been called (catastrophic) anthropogenic warming (CAGW). Catastrophic means that it is dramatic and dangerous; Anthropogenic means that it is caused by the actions of humans and the society; Global Warming means that the average temperatures across the world are increasing. This is a very complex argument, and a lot of the discussion about it is very heated. In this class, we are not going into details about these speculations, nor will it be part of any assessment. If you are interested in learning more about this, you can ask me for a variety of sources that will allow you to investigate and form your own informed opinions.

Regardless of the potential effects of extra greenhouse gases, it is a good idea to minimise pollution. Pollution can cause all sorts of problems – from the possibilities discussed above to simple things like smoke and smells, unpleasant effects on health and hygiene, to damage to the local environment. The cartoon to the left makes this point, but it misses another point – one that we have discussed in class.

We have to consider where the most of the greenhouse gases come from, particularly carbon dioxide. The most of carbon dioxide is produced by power generation – electricity! We currently produce most of our power from fossil fuels which are burnt to generate electricity, so it would be great to be able to produce power without producing as many greenhouse gases. The problem is that we need specific things from our electricity – and the power generation that we have is very good at providing these things. Alternative (or renewable) energy generation . What are these needs?

Well the first and foremost is the need to provide a constant supply – it must be regular and available when it is needed. This is called “Base Load Supply”. Some forms of renewable power are only available at certain times of the day or in certain places or environmental conditions – this is called the “intermittency” issue.

The next issue is how quickly it can generate power – from when you activate the system, how long is it before electricity is available to use? This is called the Latency issue. Some ways of generating power can take a long time to “spin-up”.

Finally, there is the consideration of any other side-effects of the power generation method – cost? danger? there are as many different possible problems as possibilities.

You have read this far; now it is your turn. Each of you must comment on this post to discuss one of the following possible power generation technologies:

  1. Hydro power (Tidal or Ocean)
  2. Solar Power (Solar Farm or Concentrated Solar/ Molten Salt)
  3. Wind Power (Horizontal or Vertical)
  4. Geothermal Power (Either Hot rock or Hot water)
  5. Biomass
  6. Any other system that you are interested in (other than Hydropower (Dam) or Nuclear power (Fission))

You have to put the following sections in your reply:

  1. A basic definition of how the generation technology works
  2. At least two advantages of the generation technology (either directly, or in comparison to fossil fuel power)
  3. At least two disadvantages of the generation technology (as above)
  4. At least one link to an internet resource about your chosen technology (e.g. a newspaper article, youtube video, slideshare powerpoint, animation or other relevant resource).

See you in class!

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22 Comments on “Energising Alternatives!”

  1. Jacqueline Crozier Says:

    Geothermal power is thermal energy generated and stored in the Earth which is accessed by drilling water or steam wells in a process similar to drilling for oil. This is a good idea for significant cost saving, reducing reliance on fossil fuels, and job creation and economic benefits, geothermal power also has environmental benefits. However, geothermal power does have its disadvantages. These include high installation costs and the fact that geothermal power is only suited to particular regions, you could also run out of steam, or release harmful gasses.

    en.wikipedia.org/wiki/geothermal_energy

    http://www.eere.energy.gov/geothermal/m/gpp_animation.html

    conserve-energy-future.com/Advantages_Disadvantages.php

  2. BIAK HLAWN CEU Says:

    BIAK HLAWN CEU

    ‘WIND POWER’

    Wind power is a form of solar energy. They are caused by the uneven heating of the atmosphere by the sun, the irregularities of the earth’s surface, and rotation of the earth. Wind flow pattern are modified by the earth’s terrain, bodies of water, and vegetation. With the invention of wind turbines, we can now harness the wind’s energy and use it instead of purchasing electricity from the utility companies that are derived from non-renewable sources.

    The terms wind energy or wind power describes the process by which the wind is used to generate mechanical power or electricity. Wind turbines convert the kinetic energy in the wind into mechanical power. This mechanical power can be used for specific tasks (such as grinding grain or pumping water) or a generator can convert this mechanical power into electricity.
    Wind turbines make electricity by working as an opposite of a fan. Instead of using electricity to make wind, it uses wind to make electricity. The wind turns the blades, the blades spin a shaft, which connects to a generator that produces electricity. But if the wind speeds get too high, a brake is deployed to slow the blades down and prevent damage being done to the system.

    Advantages:
    • The wind is free and with modern technology it can be captured efficiently.

    • Once the wind turbine is built the energy it produces does not cause greenhouse gases or other pollutants.
    Disadvantages:
    • When wind turbines are being manufactured some pollution is produced. Therefore wind power does produce some pollution.
    • Wind turbines generally produce allot less electricity than the average fossil fuelled power station, requiring multiple wind turbines to be built in order to make an impact.

    LINK: http://youtu.be/CyHOl-hetbU

  3. Jade Says:

    Solar Power
    The operation of the solar cells is based on the principle of the Photovoltaic action. Solar power works by taking energy from the sun and converting it into electrical energy.The solar cell is made up of two layers of semiconductive material joined together.When one layer is exposed to light, many electrons acquire enough energy to break away from the parent atoms and cross the junction.This process forms negative ions on one side of the junction and positive ions on the other. The advantages of solar power is that you save money of your electrical bills,generate your own electricity, reduce your carbon emissions,get paid for any excess power you export back to the grid,add value your to house and reduce your greenhouse gas emissions.The disadvantages of solar power is that the solar cells are very expensive,the solar panels only work during the day time so become useless during the night,Pollution can be a problem to solar panels as they can degrade the efficiency of the photovoltaic cells and a large area is needed for the solar panels which can be a issue if you live in a inner city apartment

    link – Book- Electronics Fundamentals : Circuits,Devices and Applications

    Website:http://www.clean-energy-ideas.com/articles/ disadvantages_of_solar_energy.html

    http://www.truenergy.com.au/solar-power/how-does-solar-power-work.xhtml

    Youtube video – How solar panels work

  4. Brooke Triangolo Says:

    Brooke Triangolo

    Solar Power

    Solar power works when the sunlight carries energy down to earth. This energy is called Photons. When the Photons strike the semiconductor in the Solar panels, electrons from the meterial itself get knocked out to form an electric current. This is electricity that people can use everyday!

    Advantages:
    solar energy is a completely renewable resource. This means that even when we cannot make use of the sun’s power because of nighttime or cloudy and stormy days, we can always rely on the sun showing up the very next day as a constant and consistent power source.
    Solar cells make absoulutely no noise at all. They do not make a single peep while extracting useful energy from the sun. On the other hand, the giant machines utilized for pumping oil are extremely noisy and therefore very impractical.

    Disadvantages:
    Solar power cannot be harnessed during a storm, on a cloudy day or at night. This limits how much power can be saved for future days. somedays you may still need to rely on oil to power your home.
    The solar cells and soloar panels that are needed to harness solar energy tend to be very expensive when you first purchase them.

    Link: http://www.clean-energy-ideas.com

  5. Biak T.Khun Says:

    Tidal power is the generation of electrical power through the harnessing of the ebb and flow of the tides.

    A barrage is built across a river estuary or bay. The barrage has gates, which allow water to flow into the barrage with the incoming tide. The ebb and flow of the tides turn a turbine which generates electricity.
    Advantages:
    1) Offshore turbines and vertical-axis turbines are not expensive to build and do not have a large environmental impact.
    2) The barrage can help to reduce the damage of very high tidal surges or storms on the land.

    Disadvantages:
    1) A barrage across an estuary is very expensive to build and affects a very wide area-(the environment is changed for many miles upstream and downstream. Many birds rely on the tide uncovering the mud flats so that they can feed. Fish can’t migrate, unless “fish ladders” are installed.

    2) Needs a very big piece of sea to be cost effective and only produces power for about 10 hours of the day

  6. Chloe Says:

    Solar Power
    How does it work?
    Solar power prodces more energy in the summer, solar poer cells convert sunlight into energy.Solar power works by when the electricity flows into your solar power electricity systerm, this is either used in your home or building or back to your electric untilty service for later on use.
    Advantages
    Solar energy is completey renewable.
    Very little maintance is required to keep solar cells running.
    Disadvantage
    Solar power cannot be harnessed during a storm or a cloudly day or at night.
    The solar cells and solar panels that are needed to harness solar energy tend to very expensive when you first purchase them.

    LINK
    http://m.youtube.com/watch?v=NDZzAIcCQLQ

  7. Wendy Says:

    Wind Power:
    How Wind Power Works~
    Wind power is a process of energy production created by man to supply us with more “earth friendly” ways to produce energy. Wind turbines are used to capture the wind, and when the blades spin the shaft connected to them helps the generator produce energy.

    Advantages To Wind Power~
    1.It is less harmful way to produce energy and creates low carbon emissions.
    2. Wind turbines do not take up a lot of space, preserving space for houses and farms.

    Disadvantages To Wind Power:
    1. There is no guarantee that wind will constantly blow. Wind is not necessarily a regular occurrence meaning that a regular energy production is not guaranteed.
    2. Wind Turbines do not produce enough energy for a large amount of the population. It would take a lot of wind turbines and a lot of land to create enough energy to power cities let alone countries and the world.


  8. […] 2012- Sustainable Energy InitiativeGlobal Warming Effects (That You’ll Never See Coming)Energising Alternatives! // IE Evitar seleccion de texto document.onselectstart=function(){ if […]

  9. Vicky Says:

    Wind power captures the energy in moving air. Wind is actually a function of solar energy. As the sun heats the earth’s surface, it does so unevenly which creates wind cycles. By tapping into these wind cycles, we’re able to create wind power, mostly in the form of electricity. Wind turbines are the tools most often used to capture wind energy and windmills were and are used to create mechanical power for pumping water and running machinery. There are both small and large wind turbines. Some are used individually to provide electrical energy to remote locations, while others are combined into large wind farms that are connected to the electric grid to provide electricity to larger communities. Wind turbines can be installed on land or offshore where winds are more consistent and strong. A wind turbine works like a fan, with the only difference that a turbine uses the wind to make electricity. Almost all wind turbines producing electricity consist of rotor blades, which rotate around a horizontal hub. The hub is connected to a gearbox and generator, which are located inside the nacelle. The nacelle is the large part at the top of the tower where all the electrical components are located. Most wind turbines have three blades, which face into the wind. The blades are turned around by the wind, this spins the shaft, which connects to a generator and electricity is made.

    Advantages:

    1. Wind energy is friendly to the surrounding environment, as no fossil fuels are burnt to generate electricity from wind energy.
    2. Wind turbines take up less space than the average power station. Windmills only have to occupy a few square meters for the base, this allows the land around the turbine to be used for many purposes, for example agriculture.
    3. Another advantage of wind energy is that when combined with solar electricity, this energy source is great for developed and developing countries to provide a steady, reliable supply of electricity.

    Disadvantages:

    1. The main disadvantage regarding wind power is down to the winds unreliability factor. In many areas, the winds strength is too low to support a wind turbine or wind farm, and this is where the use of solar power or geothermal power could be great alternatives.
    2. Wind turbine construction can be very expensive and costly to surrounding wildlife during the build process.
    3. Another disadvantage is that many reports of bird and bat mortalities are noticed in areas surrounded by wind turbines.

  10. Emily Stones Says:

    Solar Power
    Solar power is when sunlight is converted to power. Sun light contains energy and when the suns light hits an object or surface the energy turns to heat, but when light hits certain materials it can turn into an electrical current instead which we can use for power. Solar power can be used or stored for later.
    Advantages:
    1. Solar power is 100% renewable.
    2. Oil, which is what most people us to power their homes, isn’t renewable, making solar power a better choice.
    3. Solar powers make no noise so they wouldn’t disturb a home.
    Disadvantages:
    1. The solar cells and panels that are needed to start up solar power can be expensive.
    2. Solar power can not be made at night or in dark weather conditions.
    3. Solar power requires a large area to make enough energy for running a home.

  11. Maddison Veares Says:

    Tidal power is simply the making of electrical power through the flow of waves and tides. The water is first trapped in a sort of gate this gate is apart of something known as a Barrage. A Barrage is a complicated way of saying an incredibly massive DAM! Once the water has been trapped inside the gates it is no longer known as waves or water, its new name is Hydrostatic Head. Other gates open and Hydro-electric generators are now operated. This generators turn and power and renewable energy is created. Two advantages of this process is that it is incredibly cheap to maintain and run and its very predictable not to mention reliable. It is predictable because the tides and waves can be predicted. Not only does the plant need a large area of coast it also only produces energy for 10 hours a day. Other disadvantages include disruption of sea life and water is not replenished which leads to dirt and pollution remaining in the sea and around the dams.

    Bibliography-
    http://library.thinkquest.org/06aug/01335/tidal.htm#2

  12. Emily Stones Says:

    🙂


  13. Geothermal
    Geothermal energy uses heat from the ground to create electricity. When holes are drilled into the hot rocks underground, steam comes up and is purified. This is then used to drive turbines, which drive electric generators. Some times, water may need to be pumped down underground, if there isn’t groundwater there already.
    Geothermal energy is renewable, as long as too much cold water isn’t pumped down to the rocks; this would cool them down therefor stopping the steam from coming up.
    Advantages:
    -does not create any pollution, and dos not contribute to the greenhouse effect.
    -the power stations do not take up much room
    -once the power station has been built, the energy is almost free.
    -no fuel is needed
    Disadvantages:
    -expensive to build
    -can only be built on certain spots, where there is the right type of rock that is in a suitable spot to drill to.
    -hazardous gases and minerals may come up from the ground. These can be hard to dispose of safely.
    -the power station may run out of steam, and this could last for decades
    Bibliography:
    -http://www.darvill.clara.net/altenerg/geothermal.htm#renewable
    -http://www1.eere.energy.gov/geothermal/m/gpp_animation.html

    🙂


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