Alternative Energy – Things you didn’t know

October 23rd, 2006 BY Mat Conway | 31 Comments

As our energy needs rise, as our supplies of fossil fuels run out and as the state of our planet become more precarious, we increasingly need to look at alternative energy sources to meet our requirements and to allow our modern lifestyles. Each of the methods below has been touted both a possible solution and as an environmentally friendly one.

Solar Energy

The sun, a huge burning ball of hydrogen, outputs vast amounts of energy every second. Even the minute fraction that falls on the Earth’s surface is more than enough to supply all our energy needs. In total 122 PW is incident on the surface, that is 122,000,000,000MW; a whopping ten thousand times more than our total energy requirements. The energy produced is clean and solar panels are low maintenance. They are ideal for remote locations where grid connection is difficult or expensive and when used locally you can even overcome the energy loss of transportation.
Sounds great, but like with everything there are problems. The highest power output can be achieved at the equator with 1020 watts per square metre. This rapidly falls off to 125W/m2 at the north of mainland USA. Our most efficient panels can covert 15% of this energy into electricity which, if connected to the grid, must be converted from DC to AC resulting in further power loss. If you factor in the cost of panels, the current shortage of refined silicon and the unreliability of the weather solar panels start to look less attractive.

Wind Energy

Every day you can see the wind blowing, all that wasted energy just wafting away. An estimated 72TW of energy onshore it thought to be available and all you need to tap it are a few wind turbines! Currently less than 1% of the Earth’s energy needs are supplied by wind, coming in at a mere 59GW, with Denmark being the most wind friendly producing 23% of its own energy needs. The energy produced is totally clean and also one of the cheapest around; expecting to produce, on average 18 times more energy than is consumed in its construction, compared to nuclear which is estimated at around 5. People are often worried about the aesthetics of wind farms but what they often forget is the land can still be used for farming, with only 1% of the space being taken up by the wind turbines. One of the biggest concerns about wind turbines, especially with the larger 5MW models, is their affect on bats and birds. Most birds will be fine according to a study by Britain’s Royal Society for the Protection of Birds (RSPB), with the exception of birds of prey; in Norway nine out of their ten sea eagles were killed by turbines. Bats too are a serious problem, even the manufacturers of wind turbines are deeply concerned by the numbers of bats being killed. Research into this is still ongoing. Learn more about wind turbine power here.

Hydroelectric Energy

Hydroelectric is an interesting case. As a renewable energy source it is far from in its infancy, with the first hydroelectric dam being constructed in 1870 in England. Since then it has gone from strength to strength and now provides a staggering 20% of our energy needs worldwide. The biggest complex is the La Grand system of dams in Quebec producing16GW of power. It is easy to vary output to match demand just by letting more or less water pass through and it has proved to be a long lasting technology. Some concerns over pollution have arisen, especially in hotter climates, as plant material breaking down leads to the release of methane. The World Commission on Dams stated that at least 100W/m2 of stored water was needed if it was going to produce fewer emissions than a standard plant. In North American and Canada this figure lies around 8%, so although significantly better than traditional fossil fuels it is still not the cleanest option. The flooding of riverbed drastically alters the local ecosystem both up and down stream, which has knock on effects for the local food chain. The choice as to whether to further develop hydroelectric power around the world is a fairly easy one to make; almost all the suitable sites in the world have already been developed.

Geothermal Energy

All over the globe there are hotspots of underground thermal activity. Geothermal power plants tap into this natural heat source to provide power to homes. Iceland, for example, produces 170MW of energy and heats around 85% of their homes using geothermal power. The largest geothermal plant in the world is located 90 miles north of San Francisco and produces an effective 1GW of power! Most of the arguments over geothermal power are concerned with whether or not it is actually a renewable source as eventually areas will cool down, far quicker when being tapped for power. This could even be on the timescale of decades giving it a very short life span. The Icelandic government states that it should not be considered as renewable in the same way that hydroelectric is. Bearing in mind there are not as many sites for this as wind and solar (which can be used all over the world) and the high costs involved it is not the most promising of the technologies listed here.

Tidal Energy

Tidal power harnesses the energy of large volumes of water moving in and out from the coast. Tides are extremely reliable and predictable which is useful for power management. Tides occur are due to frictional forces with the moon (occurring due to gravity) and the energy dissipated by this 2500GW, enough to supply our current electrical needs, but not by that much with our current usage being estimated at 2000GW. Tidal plants are very expensive and may not see returns for years due to high build costs. The largest plant currently in operation is on the Rance River producing 240MW and was actually built in the 1960s. Scotland is hoping to have a wave power plant constructed by 2010 aiming to replace one large fossil fuel burning station.

Energy from the sun can either be used directly using solar panels, or from resulting winds, or finally from waves. Wave power has a huge potential to generate power, far greater than that of tidal and can be deployed in many more locations. Once constructed they cause no pollution. The trouble is in constructing devices that are both durable and efficient more often that not efficiency has to be sacrificed for a product that will survive long durations at sea. The first wave farm, consisting of three generators at the Pelamis Wave Energy Converter off of the coast of Portugal generates 2.25MW this is actually less than one modern wind turbine that can produce 5MW. Once again Scotland, the world leaders in terms of wave energy science, are planning on the deployment of wave devices in the near future.

The Future

All of these technologies have some problems in common. The first is the intermittency and reliability of the sources. It isn’t always windy, the sun isn’t always shining and waves aren’t always splashing. This causes the inherent problem of providing a constant power supply to users at home. On a country scale this can be solved by using spinning supplies, these would be conventional fossil fuel power stations running at low output, quickly being increased to full output to meet sudden demands. A more eco-friendly way of doing this is to use pumped hydroelectric (water is stored behind a dam until peak demand, released and then pumped back again).

A much better solution is to have a distributed system over an entire continent, when one county is producing too much it pumps its electricity over to someone else. When it’s not windy in Texas it might be blowing in New York. The other problem is that everything we do at the moment is small scale. In the same way that fossil fuels were ok when they weren’t used much, renewable sources can cause problems upon mass deployment. Enough wind farms could change air circulation in the atmosphere and therefore weather patterns. Tidal and wind will affect currents and local ecosystems, too many solar panels would prevent a lot of light falling on the earth and from is being warmed, possibly causing cooling (global dimming). Just as, at the time, we didn’t know what effects mass use of fossil fuels would have it is hard to predict exactly how the widespread use of renewable energy sources would affect the world around us; we must learn from our past mistakes and tread carefully into the future.

  1. Bert
    1

    Wind energy is being considered in my area but, local residence do not want the “eyesore” or shadows on their properties. Many farmers have the oportunity to benifit from wind turbines. They dont want wind turbines in their veiw but what would they say it we were to consider putting a coal or nuclear plant their instead.

  2. Jake
    2

    So we pretty much must have an equal balance between all of the different sources of energy. In my opinion, we should use other energy sources to have the global warming be undone, then start to balance it out, so that the planet doesn’t warm too much or cool too much.

  3. Elizabeth
    3

    I think that alternative energy is a nobrainer.If it can help the enviroment and is more cost efficient then why not use it?

  4. Isabell
    4

    There is only one problem that I can see about using alternative energy,that is the process of swithching to alternative energy from fossil fuels.The equimpment can be costly and some people are just to lazy to make the switch.

  5. Kenneth Schustereit
    5

    I find it interesting that on a recent History Channel program the statement was made that if 10,000 acres of Wyoming were converted for use of photovoltaic panels the array could power the entire US. The program left out the fact that the rest of the state and part of Utah would be needed to house the battery network to power the US when those 10,000 acres were under three feet of snow!
    Come on, folks! I’m in favor of alternative energy too but let’s be realistic here so people with a little common sense won’t be laughing at us!

  6. noah
    6

    I think its great but lets hurry up and build allot more of these thing so we can stop using fossil fuels

  7. Kenneth Schustereit
    7

    Personally, I favor the idea to triple the amount of wind farms in the US and build the new Generation III+ Passively Safe Nuclear Power plants. With the way now open to recycle spent nuclear fuel rods like France has been doing for many years nuclear power is greener and more attractive every day. These new plants use less nuclear fuel therefore requiring less uranium mining and more electrical power with less impact on the environment. Look up the new GE/Hitachi Simplified Economic Boiling Water Reactor on Google. This is an example of safe, efficient, environmentally friendly nuclear power.

  8. Jens
    8

    Halllllllllllllllooooooo

  9. KennethSchustereit
    9

    And here’s where we come up with the most extreme of the environmental extremists. AREP is opposing solar projects in California and some nutcase named Blackburn is opposing wind in Texas. Wind is also being opposed in California and Massachusetts. The most green design for a Generation III nuclear reactor is also being opposed in Texas. This new reactor type is more efficient and uses less uranium fuel per KWh of power produced and produces no green house gasses. The AREP nutcases support photovoltaic solar units on individual homes at an upfront cost of up to $17,000 to $35,000 and the use of nasty lead acid battery systems that produce hydrogen chloride gas! Go figure!

  10. stav
    10

    Wind farms won’t solve anyone’s problems.. the amount of acreage needed to produce a small amount of power makes it impractical inthe long run. In the end nuclear power will be the way we have to go.. and the sooner governments start working on safer more economical ways to harness it, the better off the planet will be.

  11. paco john
    11

    Wind is an ’Island’ technology in as much as the temporary load carring capacity requires an alternate ’conventional’ back up to maintain an even reliable delivery. These conventianial back up (fill in) power supplys are primaraily of two types ; single stage turbines or two stage boilers with excess capicity on standby. Both are very inefficient for this use and result in more energy and/or dirtier energy to have on standby than if the wind source were in the mix at all. Now if you lived as a castaway on an equatorial island and need olny intermittent supply then wind would be ideal.

  12. paco john
    12

    Wind is an ’Island’ technology in as much as the temporary load carring capacity requires an alternate ’conventional’ back up to maintain an even reliable delivery. These conventianial back up (fill in) power supplys are primaraily of two types ; single stage turbines or two stage boilers with excess capicity on standby. Both are very inefficient for this use and result in more energy and/or dirtier energy to have on standby than if the wind source were in the mix at all. Now if you lived as a castaway on an equatorial island and need olny intermittent supply then wind would be ideal.

  13. stav
    13

    As John says, wind is not constant so the power is intermittant, needeing a secondary power source, which sort of defeats the purpose…………………….

    It is a shame that this type of comments forum doesnt have a ’report’ facility, so that we can deal with the random muppets such as the one above…

  14. Scott
    14

    People need to watch Zeitgeist (google it. its a free movie online) in which you will understand the reasons WHY the entire planet isnt using these resources now. It IS a no brainer so why is it we are so brainless about it? The media rules the world and those who dont know arent being told. Spread the word everyone, spread the word.

  15. Kenneth Schustereit
    15

    Neither wind or solar, by themselves, will solve our energy problems. Individual solar/photovoltaic on homes is certainly not the answer unless you have the up front money to invest and know how to maintain battery systems. We need ABWR nuclear to provide the necessary baseload needed to provide uninterupted power.

  16. Greentechdog
    16

    I personally think we as Americans have advantages that other countries don’t always have, Perhaps it’s a matter of expanding our grid options. No one option is going to be right for everyone or for every area. Perhaps solar and hydrodynamics would be efficient in the Southwest, and Geothermic and Wind energy in the Northwest, While other parts of the country would be powered by safe nuclear power as Kenneth suggests. I think we do ourselves a disservice to exclude one form of energy or another until it has been studied fully and gone through the trials. Like Nuclear or Hydroelectric energies have had the chance to do and are still going through. They both have their issues and environmental disadvantages. In my opinion we need to give Solar and Wind or Geothermal energy research and companies time to resolve some of the efficiency hurdles to make it more enviormentally sound and energy efficient. With current trends and concerns about or dependency on foreign oil and just plain old bad practices from the past now is not the time to put all our energy eggs in one basket.

  17. meagan
    17

    Where do the energy come from?

  18. Jhenebive
    18

    …..Ah oKEi i uNdersTand…!

  19. Jhenebive
    19

    Comment already exists or is waiting for approval.

  20. maqueino
    20

    can you say the energy problems??please!

    • Responses to maqueino
      21
      franzel says:
      January 29

      i hate enegy

      • 22
        Dillon Driver says:
        December 13

        Without Energy you wouldn’t have a computer to be typing on

  21. ferdi
    23

    Clearly it has to be wave energy. Waves never stop like the wind or sun, don’t blow up like nukes, don’t blow smoke like coal, and hide beneath the water line. Some sea floor would be destroyed, but that’s a sacrifice, and I’m sure the sea-life would come back to some degree.

  22. sammy
    24

    the problem with alternative energy is the cost and the low energy density in it. we could live off renewable energy, if we used 10% of the energy we use now, which means not buying half as much stuff as we do, using cars a LOT less, less air conditioning, less everything. a consumerist society can’t be powered by alternative energy
    but oil production will peak, then we’ll have less energy available, and society then will break down
    maybe a high energy using civilization just can’t survive as long as many people think

  23. advantages of wind energy
    25

    This is very imformative thank you. Alternative energy is going to be the future with less dependence on oil.

  24. Dillon Driver
    26

    I think Alternative Energy is something that should be used so that we are not wasting fossil fuels that can be used for something else like science, or developing new equipment that can help us in the future.

  25. reallysickofit
    27

    how about this, we stop having so many kids. only one kid per couple till the worlds population is down to 150 million. surely if the human population was down to that level, there wouldn’t be enough people left to do too much damage.

  26. btelis
    28

    very interesting article, thanks for sharing

  27. fotovoltaika
    29

    Thank you for sharing this informations i really didnt know before reading this article…

  28. polis
    30

    Lets make this planet better we must use alternative energy if we want our childrens have a good life.

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    31

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