Renewable Energies

Hi Everyone,

In the wake of the Lynas controversial rare earth project at Pahang, let us evacuate the various renewable energies and the pros and cons of each of them.

Renewable energies comes from natural sources and can be reused. It includes hydroelectric, wind, solar and also nuclear.

Hydroelectric

The main source of hydro electricity is water. Water is present in over 70% of the Earth. Hydroelectricity is generated by huge amounts of water located at a very high terrain such as waterfalls and dams. Huge amounts of water streaming down a waterfall will generate a high amount of kinetic energy which in turn generates enough power for electricity.

Currently, hydropower powers over 24% of the electricity in the world and supply more than 1 billion people with power. It is one of the largest renewable energy source in the world.

To know more about how hydroelectric works, please visit How Hydropower Plants Works¹ website powered by HowStuffWorks.com.

Here are some advantages and disadvantages of hydroelectricity:²

Advantages

Constant electricity production
Clean source of energy
Cost less then fossil fuel
Recreational activities

Disadvantages

Expensive to built and needs to be high quality
People need to move out of the valley when a dam is built
May cause serious geological damage

Wind

Wind can be converted into energy through the use of windmills for mechanical power, wind turbines for electricity and wind pumps for water pumping or drainage. A large wind farm may consists of hundreds of wind turbines that are connected to the power network.³

 A wind turbine operating at a wind farm normally generates 65% to 80% of the time. The wind speed may not be at optimum levels. The capacity factor is about 30% to 35%.<sup>4

Here are some advantages and disadvantages of wind energy:4,5</sup>

Advantages

Free and renewable resource
Less expensive to construct
No air or water pollution

^{Disadvantages}  

Noise generated by the wind turbines (rotors)
Negative impact on wildbirds and bats
The glistening blades of windmills are an eyesore
Wind blows intermittently
Good wind sites are loacated in remote locations

Solar

Sun is present everyday in our lives, more so in countries nearer to the Equator. It is also present in Australia during summer.

Leveraging on the presence of sun, it can be used as a source of clean and renewable energy. It is also used in devices such as a calculator.

There are two ways to capture solar energy that is passive and active solar depending on the way they capture, convert and distributable solar energy⁶. Active solar technologies use photovoltaic panels and solar thermal collectors to harness the energy. Passive solar include orienting buildings to the Sun and designing speaces that circulate air. 

Solar energy uses include water heating system, electric vehicles, electricity, running satellites that orbit the earth, power convertors for electric motor drives and for emergency lighting^7,8.

Malaysia is also going to have its solar power plant that is going to be located at Putrajaya. It is an initiative by Tenaga Nasional (TNB)⁹.

Below are the advantages and disadvantages:

Advantages

Solar energy is free
Good for sunny countries especially in areas that have no easy way to get electricity
Efficient energy

Disadvantages

There must be presence of light to generate solar energy
Expensive to build solar stations
Not reliable in a climate that is not sunny

Nuclear

Nuclear through the process of nuclear fission can be used to generate electricity as well. Nuclear power plants has provided about 6% of the world's energy and 13% to 14% of the world's electricity. Among the countries using nuclear energy are the U.S, France and Japan¹⁰. 

It is widely debated that nuclear energy is good. On one hand, nuclear can be a clean energy resource but on the other hand, if safety measures are not implemented thoroughly, it may cause harmful radiation to be released.

The most talked about nuclear disaster were Chernobyl (Russia) and the recent Fukushima nuclear reactors in Japan which was damaged during a tsunami last year. It also prompted the unhappy reaction of residents over the proposed Lynas rare earth project in Pahang, Malaysia.

Advantages^10,12,13

No emission of any poisonous gases
Generates a high amountt of electricity energy in a single power plant
Readily available

Disadvantages


Safety of nuclear reactors are top priority
It may be used to produce nuclear weapons
Health risks and environmental damage


Here are also some myths and facts about nuclear energy from Nuclear Energy Institute:
Myths and Facts About Nuclear Energy

In a nutsheel, each renewable energy has its pros and cons. Which one is the best one of all?

Nuclear energy may have its advantages but many are still sceptical about it. 

The highest risk would be nuclear energy as well. The source of energy that has the lowest risk would be solar and wind. 

Hydroelectric and solar energy are a better renewable energy sources in most parts of Asia because of the climate and weather. Wind energy is used more in western countries and Australia. 

For me, it should be hydroelectric and wind energy. These sources are the cleanest of all. There may be an issue regarding the issue of building a hydroelectric dam as it can damage the environment and wildlife but it is also a source of energy that is low risk.  We can say the same for wind but it may not run at full capacity at all times. Wind energy is not suitable for countries like Malaysia because there isn't enough wind here to generate the electricity.

Solar is the alternative choice being that it may take a long time to generate enough power. It is great for countries that have sunny weather all year round such as Malaysia and Indonesia. 

Nuclear power is clean but the radiation it emits may cause health risks even though the amount of radiation is very small. Safety also remains the top concern for nuclear power reactors for it may be harmful when the radiation is releaded. There is research that shows nuclear power plants are safe though¹¹.

Discussions and more detailed research can also be done to have a better understanding of all these source of energies. It may be further discussed in different posts in the future. This is only a summary of the sources of renewable energy. There can be different opinions on all these as well.

Cheers,

Rogerkoo

¹Bonsor, Kevin.  "How Hydropower Plants Work"  06 September 2001.  HowStuffWorks.com, http://www.howstuffworks.com/environmental/energy/hydropower-plant.htm   
Accessed: 31 March 2012.

² What are the advantages and disadvantages of hydro-electric power - Answers.com, Wiki Answers, http://wiki.answers.com/Q/What_are_the_advantages_and_disadvantages_of_hydro-electric_power, 
Accessed: 1st April 2012 

³ Wind power - Wikipedia, the free encyclopedia,http://en.wikipedia.org/wiki/Wind_power, 
Accessed: 1st April 2012 

⁴ National Energy Education Development Project: Energy Infobooks - Secondary, http://www.need.org/needpdf/infobook_activities/SecInfo/WindS.pdf
 Accessed: 7th April 2012 

⁵ Wind Energy Bascis, Wind Energy Development Programmatic EIS, http://windeis.anl.gov/guide/basics/index.cfm
 Accessed: 7th April 2012

⁶ Solar Energy- Wikipedia, the free encyclopedia, http://en.wikipedia.org/wiki/Solar_energy
 Accessed: 7th April 2012

⁷ Energy Resources: Solar, www.darvill.clara.net/altenerg/solar.htm
 Accessed: 7th April 2012

⁸ Solar | Department of Energy:, http://energy.gov/science-innovation/energy-sources/renewable-energy/solar
 Accessed: 7th April 2012

⁹ The Star Online: Malaysia's first solar power plant:, http://biz.thestar.com.my/news/story.asp?file=/2011/2/23/business/8114613&sec=business
 Accessed: 7th April 2012

¹⁰ Nuclear Power- Wikipedia, the free encyclopedia, http://en.wikipedia.org/wiki/Nuclear_power
 Accessed: 8th April 2012

¹¹ Nuclear Energy Institute - Myths and Facts About Nuclear Energy, http://www.nei.org/newsandevents/nei-backgrounders/myths--facts-about-nuclear-energy
 Accessed: 8th April 2012

¹² Benefits of Nuclear Power, http://www.benefitsofnuclearpower.com/
 Accessed: 8th April 2012

¹³ Pros and cons of nuclear power | Time for change, http://timeforchange.org/pros-and-cons-of-nuclear-power-and-sustainability
 Accessed: 8th April 2012