The futures not orange....its green! (Alternative energy sources)

Member Name: Sarah_Louise

Product:	Alternative energy sources
Date:	24/02/01 (85 review reads)
Rating:

Advantages: Non-polluting, renewable....the list is endless!

Disadvantages: None when you think of the alternatives!

I suppose all people reading this opinion are at least a tiny bit interested or at least slightly concerned about the current problem the world seems to have stumbled across about this fossil fuel business.

Well if you are - that's great....it's a start isn't it!

I first became aware of this problem when I was a little 'un because my dad had, and still does, work for hydro-electric power stations. He's fanatical about hydrological power, so I guess its rubbed off on me some what!

Then once I'd made my way through primary school I first became aware fully when I was in a year 7 science lesson. This really made me worry....I'd not realised just what we were doing not only to us and other living things on this earth - but to the whole planet! It's disturbing to think about really! (And they say we're the most intelligent species?!?! [but that's a different topic altogether!]).

Now for information about what we can in theory but should in practice be doing to help our planet Earth out a little:

Alternative energy sources can come from all different aspects really, from the wind, sun, water down to geothermal aspects.

Before I leap into the deep end and start talking about the individual alternative energy sources i'll tell you all what the main problem(s) there are with fossil fuels.

~ Introduction ~


Oil and gas:

Phytoplankton are tiny floating plants called algae. The commonest are golden or brown coloured diatoms and dinoflagellates [try saying that in a hurry!].

Oil and natural gas formed by decay processes from microscopic life forms called phytoplankton which floated in the world's oceans millions of years ago. Just like today's phytoplankton, they harnessed the Sun to photosynthesise and store energy.

When these plants died, they sank to the sea floor and became mixed with in with the mud and so were
gradually buried.

Eventually the muddy layers gradually became so thick that it started to harden into rocks.
Heat from the Earth's core and the weight of the rocks gradually changed the energy containing substances in the plants into hydrocarbon liquids and gases.

(Hydrocarbons are simple molecules made up of carbon and hydrogen atoms joined together in chains or in rings).

These molecules, being light and mobile, migrated upwards through the rocks but eventually became trapped beneath impermeable rock structures in the Earth's crust. The oil and gas companies around the world know how to find these trapped reservoirs and release their contents by drilling holes into them. As everyone knows, crude oil and gas from these deposits form the basis for the world's largest energy industry:

oil and gas.


That all sounds great, and it is, or at least it was!

~ Problems ~

Supplies are limited. We're using fossil fuels up too quick. Phytoplankton aren't dieing, sinking and becoming buried quick enough to keep up with the demand!

We also know that every drop of oil we burn adds to the ever increasing environmental problems.

Carbon dioxide is now considered by many scientists to be a major cause in global warming.

Burning is really oxidation; this makes carbon and oxygen combine to liberate heat energy.

But as you can imagine, on combining carbon and oxygen, the main byproduct is CO2.


~ So what can we possibly do to help the Earth? ~


~ Hydro Electric Power ~
(HEP for short!)

This basically consists of a dam holding water back at a higher level than the turbines in the station. This water held within the dam has a lot of potential energy. Once this water is allowed to flow down the pipes, this potential energy is converted into kinetic energy. This increases as it flows faster and further down the pi
pes to where the water then reaches a set of (or just one) turbine blades. These blades are then set turning, which in turn generates electricity.
Simple enough you'd think so what are the advantages and disadvantages?

~Advantages~

Renewable,
non-polluting,
doesnt damage the over-all landscape too badly (if well designed),
not too expensive to keep running (after initial start-up costs),
we have enough rain in the UK!

~Disadvantages~

Very expensive start up costs,
requires a fair amount of maintanance,
could be seen as damaging to the landscape.

So, all in all, the advantages out-weigh the disadvantages don't you think?


~ Solar energy ~

This is the use of the sun's rays. This method uses what's known as "photovoltaic cells" (basically a solar cell) which convert the suns rays into electricity via the "photoelectric" effect (which just so happens to be what Einstein won the Nobel Prize for!).
Now for a basic science lesson:

A photovoltaic cell is an electrical power supply. Incoming radiation provides energy that is transferred to an electric circuit via the motion of charged particals. The 2 materials of a solar cell are designed so that the electrons spontaneously drift from one to the other, giving one a negative charge and the other a positive charge - until drifting is halted by the build up of electric charge.
When radiation is absorbed by the cell, some of the electrons gain enough energy to move freely. Some move back across the boundary, others move around the external circuit and are replaced by more electrons drifting across the boundary.
The continuous flow of charged particles consitiutes an electric current. From applying mathematical formulae to work out which current, time intervals, charges, etc are best you can get a very efficient photovoltaic cell.

~Advantages~

C
heaper than most alternative energy sources,
non-polluting,
can work on a large and on the small scale.

~Disadvantages~

No major ones, but yes, you've guessed it....we live in the UK and the weather here isn't great! Although new technology here is helping that (some of the new photovoltaic cells have tilting mechanisms on now so that they can track absolute best angle (and direction) to the Sun.


~ Wind power ~

This is pretty much like the idea of HEP stations, except without the water!

It basically involves a set of blades rotating, again producing kinetic energy, which can then turn the generators to generate electricity. The ideas involved are pretty much the same.

~Advantages~

Non-polluting (starting to see a pattern with all these alternative energy sources now huh!),
doesn't greatly damage the environment which it is set up in.

~Disadvantages~

Quite expensive start up costs,
some people don't like the look of them, some people who live by them find them rather noisy,
like with solar power it depends on the weather.

So there's 3 solutions to the worlds ever decreasing fossil fuels and ever increasing greenhouse effect.

There are other sources too - e.g. tidal power (I have to confess...don't really know anything about this though!), geothermal energy - which is, as its name suggests, using the heat sources from the earth...by this I mean natural resources - like the earth's core.

For more information on alternative energy sources I'd advise you to visit the "Centre for Alternative Technology" (if you haven't already!), in Machynlleth in North Wales. Infact, why not read my opinion on that too!....aaah, what a plug!

It's a brilliant place but, if you can't make it there, take a look on thier website:

www.cat.org.uk


We really should start pa
ying more attention to these alternative energy sources if we are to remain on this planet (although we're already on-about going and mining on the moon and Mars - so who knows!)

Fossil fuels are rapidly running out, the whole in the ozone layer isn't shrinking....but there's still not many people taking it seriously!

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