Solar + Thermal +Wind = ELECTRICTY

Have you heard about solar energy, the energy harnessed from the sun? How about Thermal energy, the energy harnessed deep within the earth? Or how about Wind Energy, the energy harnessed from the air currents? If you did, did you know these different energy sources can be combined to produce yet another energy source? It is called Solar Chimney Technology. Yes literally a chimney similar to chimneys found in household only bigger!

(Image from http://www.renewableenergymagazine.com)

According to http://www.renewableenergymagazine.com, a solar chimney power plant consists of a circular transparent collector raised a certain height from the ground, with a chimney at the collector centre. A single turbine or multiple turbines are located at or near the base of the chimney and are connected to an electric generator or generators.

So how does the Solar Chimney work?

(Image from http://en.wikipedia.org/wiki/Solar_chimney)

(Image from http://en.wikipedia.org/wiki/Solar_updraft_tower)

Radiation from the sun penetrates the collector (Solar Energy) and strikes the ground surface beneath (Thermal Energy), which is heated and in turn heats the adjacent air (Wind Energy), causing it to rise. The warm rising air is trapped underneath the collector, but rises up into the central chimney, causing the air under the collector to be channeled into the chimney as well. The air flowing into the chimney drives the turbine or turbines which subsequently generates electricity cited by http://www.renewableenergymagazine.com).

(Image from http://www.solar-chimney.biz)

So why use Solar Chimneys?

• Solar chimney power plants utilize beam and diffuse solar radiation. Therefore, although reduced, the plant still generates power under cloudy conditions.
•  The ground (soil) underneath the collector of a solar chimney power plant acts as a natural energy storage mechanism, which allows the plant to generate power at night.
• Construction materials that are used for such a plant are relatively inexpensive and readily available.
• The plant does not require any non-renewable fuels in order to operate and does not produce any emissions. This also means that the plant would never have to deal with escalating fuel costs.
• At suitable plant sites such as desert areas, solar radiation is a very reliable input energy source. Consequently, energy produced by solar chimney power plants will not produce power spikes which may occur with schemes such as wind energy generation.
• Solar chimney power plants do not require any cooling water making them ideal for use in water resource poor areas.
• Low maintenance cost.
• Improved ventilation rates on still, hot days
• Reduced reliance on wind and wind driven ventilation
•  Improved control of air flow though a building
• Greater choice of air intake
• Improved air quality and reduced noise levels in urban areas
• Increased night time ventilation rates
• Allow ventilation of narrow, small spaces with minimal exposure to external elements

(Cited by http://www.renewableenergymagazine.com and http://en.wikipedia.org/wiki/Solar_chimney)

Posted by: Dan Kevin Trinidad

Heats up

Ever been on a steam bath before? If you did, did you know where it originated from and how it is made? Well the first steam baths where used and designed by the ancient Greeks and Romans. They used pipes and pumps that bring the hot water up to the pool areas, wherever the natural springs exist (cited by http://en.wikipedia.org/wiki/Steambath). Did you know that these natural hot springs are heated by the core of our very own planet?

 (Image from http://en.wikipedia.org)

Geothermal Energy is heat generated from the Earth. It came from hot shallow rocks and water and even in deep beneath the earth. It can be used to generate electricity. So how do people utilize this and use it as a form of alternative energy? According to www.nationalgeographic.com, there are three types of geothermal power plants: Dry Steam, Flash and Binary.

(Image from www.inlportal.inl.gov)

Dry Steam is the oldest form of geothermal power plant. It pulls out steam from fractures in the ground and uses it to drive the turbine to produce electricity.

(Image from www. technologystudent.com)

Flash Power Plants pull high pressured hot water into cooler, low pressured water, the steam that is generated will be used to power up the turbine.

(Image from http://www1.eere.energy.gov)

Binary Power Plants the hot water is passed by a secondary fluid. It causes the fluid to evaporate that drives the turbine.

Geothermal Energy has its advantages and disadvantages, Geothermal Energy can be extracted without the use of any burning of fuel, and especially no emission of smoke and it is available all the time. On the other hand, its release of hydrogen sulfide, a gas that smells like rotten egg and another is the disposal of a toxic fluid (cited from www .nationalgeographic.com).






Posted by: Kevinross Bool

Biological Power

Plants provide us with many things, food that we eat, air that we breathe and many more others, including energy. Through the process of photosynthesis, plants absorb energy from the sun; the energy stored can be used as a renewable energy source called biomass (cited by http://en.wikipedia.org/wiki/Renewable_energy).

Biomass is derived from living, or recently living organisms. It can be used directly as an energy source, or turned into other products like biofuel. Example of biomass sources are trees, food crops, algae, agricultural, forestry byproducts, and garbage (cited by http://en.wikipedia.org/wiki/Biomass, www. nationalgeographic.com).

(Image from http://blog.helblingsearch.com)

So how is biomass converted to energy? According to http://dsc.discovery.com, biorefining is the process of “refining” biomass to produce fuel, energy and chemicals. Burning wood is an example of turning biomass into energy. Steam that is generated from burning can be used to power turbines to generate electricity. 

(Image from http://reepedia.com)

Methane gas, found in dead organisms, can be used as an alternative for petroleum fuels.

Biomass lessens solid waste products, using it as energy, fuels and electricity are cheaper, but its environmental impact is as great as fossil fuels. Biomass produces carbon monoxide, nitrogen oxide and other pollutants in the air, resulting in global warming (cited by http://en.wikipedia.org/wiki/Biomass).

(Image from http://www.shutterstock.com) (Image from http://4.bp.blogspot.com)

Posted by: Dan Kevin Trinidad

Biofuel

Tired of hearing all those oil price hikes? Or of those smoke coming out of a car into your face?

(Image from https://lh3.googleusercontent.com)

(Image from http://penyields.files.wordpress.com)

Did you know that fuel combustion from cars is one of the main contributors for air pollution? Fuels that are burned by cars produce carbon dioxide. Because of these reasons, Biofuels are gaining popularity. Fossil fuels such as coal and petroleum came from decomposed plants and animals under the ground for million of years. But these fuels are limited only. Biofuels, on the other hand are extracted from plants, which can be replanted and reproduced (cited by www.nationalgeographic.com).

How does biofuel be an alternative to petroleum fuel? Different kinds of sources of biofuels produce different kinds of biofuels.

(Image from http://www1.eere.energy.gov)

Bioethanol came from sugar and starches. It is produced by the action of microorganism and enzymes through fermentation. Ethanol fuel is the most common biofuel, it can also be a replacement or be mixed in gasoline, because of the high octane rating of ethanol it increases an engine’s compression ratio for increased thermal efficiency (cited by http://en.wikipedia.org/wiki/Biofuel).

(Image from http://www.hielscher.com)

Biodiesel came from oils and fats through the process of transesterification. Biodiesel can be used in any diesel engine if mixed with mineral diesel. Biodiesel contains a lesser amount of carbon than oxygen and hydrogen; it improves combustion and reduces emission of un-burnt carbon (cited by http://en.wikipedia.org/wiki/Biofuel#Biodiesel).

Unfortunately despite the advantages of biofuels, there are still its disadvantages. According to www.thegreencarwebsite.co.uk, Biofuels affect biodiversity; forests might be sacrificed to give way for new biofuel plants. The debate of food vs. fuel, farmers might produce crops for fuel rather than for food. Carbon emissions, some studies show that some plants when burned produces the same amount of carbon as of fuel fossils.


Posted by: Dan Kevin Trinidad

Hydroelecticity / Hydropower

Water is the most essential component of life. Without it, we cannot live. But did you know that water can be used in different activities rather than drinking, or washing? Yes, that’s right! Water can also be used to generate electricity. It is called Hydropower or Hydroelectricity. So what exactly is hydropower? Well according to http://environment.nationalgeographic.com,  Hydropower is electricity generated using the energy of moving water. It is the most widely used form of renewable energy, accounting for 16 percent of global electricity consumption, and 3,427 terawatt-hours of electricity production in 2010, which continues the rapid rate of increase experienced between 2003 and 2009 (cited by http://en.wikipedia.org/wiki/Hydroelectricity). 

(Image from talegrapgh.co.uk)

(Image from flowersplane.com)

Ever heard of a Dam? A dam is barrier, typically of concrete, constructed to hold back water and raise its level, the resulting reservoir being used in the generation of electricity or as a water supply.
These types of structures are built mostly where there is a natural lake or a big river in a valley to efficiently get the energy out of the flowing water. The reason for holding back the water in dams is to create more pressure so that when the water is released, it can create more electrical power.


The Good thing in hydroelectric power is, it is a renewable source of energy.  The water stays in the water cycle and keep producing energy endlessly.

(Image from photobucket.com)

 

Here are some advantages and disadvantages of hydropower.

Advantages: 

1. Once a dam is constructed, electricity can be produced at a constant rate.

2. Dams are designed to last many decades and so can contribute to the generation of electricity for many years / decades.

3. The lake's water can be used for irrigation purposes.

4. When in use, electricity produced by dam systems do not produce green house gases. They do not pollute the atmosphere.

Disadvatages:

1. Dams are extremely expensive to build and must be built to a very high standard.

2. People living in villages and towns that are in the valley to be flooded, must move out. This means that  they lose their farms and businesses.

3. The high cost of dam construction means that they must operate for many decades to become profitable.



Posted by: Mary Rose Tolentino