Renewable Energy

Hello, everyone. Today, I want to share my ideas about the ecological engineering. The ecological engineering is the design of sustainable systems, consistent with ecological principles, which integrate human society with its natural environment of the benefit of both. The complexity and diversity of natural systems cause a high degree of spatial variability, it made me thinking about when we do a project design in an area, what natural resources it has in that certain area. Can we use that resources to have better design with destroy the local natural systemIt is related to questions-

  1. What is here?
  2. What will nature permit us to do here?
  3. What will nature help us to do here?

From the three questions made thinking about the energy. Because every city has its typical weather and its special natural resource. For example, windy city has more wind power can be used, more sunshine city has more solar energy can be used. City close to rivers, lakes and ocean, has more hydro power can be used. However, what is the most commonly used energy in our cities? Have we take the advantage of our local natural resources to make city better?

To find the answers of these questions, I want to start with the current problem we have in our society.

Problem: Global warming

Global warming has become an issue of global concern. It is due to continuous accumulation of greenhouse effect, resulting in unbalanced energy absorption and emission from the earth’s gas system. Carbon dioxide (CO2) is an important heat-trapping (greenhouse) gas, which is released through human activities such as deforestation and burning fossil fuels, as well as natural processes such as respiration and volcanic eruptions.





source from: Global Climate Change vital signs of the planet

From these, we know that main reason causes the global warming is due to human activities which consume too much natural resources. It makes me think what are we using so much natural resource for? Where is so much carbon dioxide emissions coming from?


In our daily life, energy is everywhere, car, ships, airplanes, electricity. Every city need energy to support their daily work. The problem is energy generation is the main reason cause of air pollution and the leading cause of global warming emissions. Can you image our life without these energies?

The problem of the Energy

With growing human population, it needs more natural resources to meets the needs of human. As we all known, the resources of our planet are finite. Most of concerns in society is that we are now running out of energy in the future. In the past, we didn’t pay attention to natural environment, which it currently leads to degraded and unstable ecosystems, loss of biodiversity, land degradation, resource depletion, increasing pollution and climate change. After first industrial revolution, we used much more natural resource with growing population and increasing resource consumption, which is exceeds the regenerative capacity of Earth.

Therefore, we know the energy is important, we cannot live without energy, however, it needs a lot of natural resources to provide energy we need. It comes with air pollution and climate change. Based on these problems, scientists find a way to solve these problems, which is get clean renewable energy sources to reduce the needs of high polluted energy sources.

While to use the renewable energy to replace the dirty energy, we need to find out what is most of dirty energy used for.

Energy distribution

Source from: Enerdata

the graphs above show, global energy consumption distribution from 1990 to 2016. From the graph we know that three main energy we used are oil, coal and gas.

Next I am going to use America as an example. Let us see how the United States, which is a developed country and high-tech center, uses these resources.

As we all know, Petroleum, natural gas, coal, renewable energy, and nuclear electric power are primary energy sources. Electricity is a secondary energy source that is generated from primary energy sources. (U.S. Energy Facts Explained)


From the graph, we can it has same distriuction of the world energy distribution, which use oil, gas and coal as three main natural resources to produce energy.

Natural resources to produce energy

In 2016, the total of energy consumed can be divided into 5 sectors were (U.S. Energy Facts Explained):

  1. Electric power—39%
  2. Transportation—29%
  3. Industrial—22%
  4. Residential—6%
  5. Commercial—4%

The electric power generated most of electricity and the other four sectors works based the electricity power. Therefore, we know the electricity power is most important energy to  a country, and they use different types of natural sources to produce electrical power.


Then what kind of sources American use to produce electric power? How much it used to another sector. For example, the renewable energy there is 55% used for electric power, however, it only has 8% used for residential and commercial. Although it has different distribution of energy consumption, I find most of energy are used for electric power and transportation. Therefore, I am going to focus on more about electric power and transportation, which caused most of energy consumed.

Renewable energy

Now, we know  the most of natural resources are used for electri power and transportation. At this stage, coupled with concerns over clmiate change, makes it even more obvious that the electricity generation industry and transport industry must move away from dirty energy and towads renewables once and for all.


Renewable energy is produced using natural resources that are constantly replaced and never run out. On the other hand, we should explore more renewable energy actively such as solar energy, geothermal energy, wind energy, biological energy, etc

I am not going to discuss every renewable energy, just like the primary energy. What I am interested is what is the main energy cause the climate change and air pollution, and find the best renewable energy to replace it? Therefore I am going pick couple of most popular renewable energy we currently used.


Hydroelectricity is electricity produced from hydropower. In 2015 hydropower generated 16.6% of the world’s total electricity and 70% of all renewable electricity and was expected to increase about 3.1% each year for the next 25 years. (from wiki)

Nine of the ten largest power plants in the world are hydro, using dams on rivers. China’s Three Gorges leads with 22.5 GWe, then Itaipu in Brazil with 14 GWe and Xiluodu in China, 13.9 GWe. The main advantage of hydro power, it can use their capacity to reduce river high peak flow in the rainfall days, which can prevent the flood at the local area. In 2012, the global hydropower generation increased by 4.3, which was higher than the historical average. The net growth of power generation all came from China, which accounted for 100% of the annual growth of global hydropower, which was the record of the single largest annual increase of single

As I mentioned before, the dydroelectricity is build base on local condition. It is easy to knwo that it has to be built on the rivers. therefore, this energy is only suit for the city who has rivers. These cities who use coal, gas, oil to produce electric, it can change to hydroelectricity.

wind Energy

Wind power is the use of air flow through wind turbines to mechanically power generators for electric power. Wind power, as an alternative to burning fossil fuels, is plentiful, renewable, widely distributed, clean, produces no greenhouse gas emissions during operation, consumes no water, and uses little land. (from wiki)

The method is to transmit the rotational power of the rotor (composed of aerodynamically propelled blades) to a generator through a propeller shaft. As of 2008, wind-generated electricity around the world is about 94.1 million kilowatts, and the supply of electricity has exceeded 1% of the world’s consumption. Although wind energy is not a major energy source for most countries, it has grown more than fourfold between 1999 and 2005.

Solar Energy

Most of common way to use solar energy is using solar panels to collect the solar energy from the sun and that can be turned into power to produce thermal heat or electricity. Nowadays, many family and companies equipped with solar panels. It is being widely used around the world. 

Another example, Japan is gradually developing zero-energy home. Zero-energy home refers to a house that does not consume conventional energy and is entirely dependent on solar energy or other renewable energy. It can reduce carbon dioxide emissions and save human energy consumption. Japanese government has plan to reach 50% of new building house with zero-energy home in 2020, and 100% in 2030. With the support of Japanese government, I can see the future of Japan live with renewable energy.

Nuclear Energy

There is a lot debate about whether the nuclear energy is renewable energy or not? It has low carbon emmission, and also it has very small environmental impact. It produces radioactive, high-level waste. The differnece is like plastic takes a long time to decomposition, while the hazard of nuclear decrease with time.  Waste that results from nuclear energy production needs to be dealt with safely. From my opion, we do not need to define whether or not the nuclear energy is renewable energy. The only thing I know is the countries who has nuclear knowledge, they are planning to build more nuclear power plant with high efficiency power generated. That is reason why I put the nuclear energy at the list. 


With the development of vehicle, there is a lot problems come with growth of transporation. when there is more vehicles, they consumed more volume of fuels. It resutls in a large amout of pollutants emission. Netherneless, the increase of energy consumption in transport sector has been the fastest in all economic sector.

In America, the transportation sector is a major segment of the US economy: about 1 in 5 dollars in the US is spent annually on transportation products and services, and 1 in 16 Americans is employed directly by this sector. The transportation industry is also an important part of the city’s operations and it is an essential part of our lives. Main energy used for transportation is petroleum, there are so other energy used for transportation, such as gasoline and diesel. With the increasing number of users on the transportation, which create air pollution and contribute to global warming. The transportation sector has the fastest growing carbon emissions of any sector, with some 67 million new cars being produced each year.

At this condition, it is very essential to use green energy instead of polluting energy. The mechanical engineers create new energy cars such hybrid cars, electric cars, solar cars to reduce carbon dioxygen emissions.

Long term vs Short Term

Compare to fossil fuel energy, the renewable energy can be reused long time(hydropower), and free to get (river, solar, wind) with less impact on the enviromental, less carbon emission. In the long-term view, we know it is good to use renewable energy, however it still has weakness which i will talk about it in my vblog. In the short term view, most of energy we are using is fossil fuel energy. It is hard to change current energy consumption, for example we cannot produce all vehicles which can only use renewable energy no matter in techical problem or long term profit. It will takes a long time to change this fuel consumption. 


I hope this blog help you understand more about the renewable energy, and realise what current sition we are experiencing. For me, I think the world has already concerns about the energy and do care environment of every country. With development of renewable energy, I can see the future with more clean environment, and there is harmonious co-existence between man and nature.

In my vblog, I am going do more deep thinking about the renewable energy with talking about advantages and disadvantages, and also i will talk more about the future with long term view of renewable energy.


Thanks for reading


Enova Energy Group:

Wikipedia about Hydroelectric, Solar energy, nuclear energy, wind energy



R.J. Fuller,2005,  Renewable Energy and Sustainability– An Evaluation

Energy Education:

American Physical Society Sites:
world nuclear association:

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