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Advantages of renewable energy
The first advantage of renewable energy is that it can be renewable, has an extremely large reserve, can be endless. Forms of energy such as solar, wind, geothermal, ocean waves, rain... are available and free to use, without fuel costs. Biomass energy also has large reserves and low fuel costs. Compared to traditional energy sources such as coal, oil, natural gas, which are increasingly depleted, only meeting human energy needs for about 50-70 years, this advantage is a strength. outstanding.
The second advantage of renewable energy is that it is abundant and can be widely exploited in all different areas of the earth. For example, with solar energy, people can exploit it anywhere, as long as there is sunlight, it can be used to generate heat to make hot water, heating, and generating electricity through the system. Solar power with solar panels… Or with wind energy, this energy source has been used for hundreds of years to move sailing boats, hot air balloons, windmills for irrigation systems. … or the current trend is to produce electricity from wind in many countries around the world.
Despite many great advantages, renewable energy also has some disadvantages, such as:
Due to the influence of nature, renewable energy is less stable than traditional energy sources. Solar energy can only be exploited during the day on sunny days, and at night or on cloudy and rainy days, the system will not work. Or with wind energy, wind turbines can only generate electricity at times when the wind speed is in the range of 4-25 m/s. Wind speed must be at least 4 m/s for the wind turbines to start running smoothly and generate electricity, but if it exceeds 25 m/s, the turbines will stop working to avoid damage in windy conditions. strong.
Requires advanced technology and high cost is also a drawback of renewable energy. To take advantage of renewable energy sources to generate electricity, it requires advanced technology and relatively high investment costs. Currently, the cost of electricity generation from renewable energy is generally higher than the cost from fossil energy. However, the development of renewable energy in the global trend has helped to reduce costs and increase efficiency, gradually improving this shortcoming.
Solar energy collected on Earth is the energy of the stream of electromagnetic radiation coming from the Sun to Earth. We will continue to receive this stream of energy until the nuclear reaction on the Sun runs out of fuel, about 5 billion years from now.
This energy can be obtained directly through the photoelectric effect, which converts the solar photons energy into electricity, as in the solar cell. The energy of the photons can also be absorbed to heat objects, i.e. convert to heat, used for solar water heaters, or boil water in the solar tower's thermoelectric machines, or heat systems such as solar air conditioners.
The energy of the photons can be absorbed and converted into energy in the chemical bonds of photochemical reactions.
A natural photochemical reaction is photosynthesis. This process is thought to have stored solar energy in non-renewable fossil fuel sources that the industries of the nineteenth to twenty-first centuries had been making use of. It is also the process that energizes all natural biological activities, for livestock traction and firewood, traditional renewable bioenergy sources. In the future, this process could help create renewable energy sources in biofuels, such as liquid fuels (biodiesel, vegetable oil fuel), gas (biogas) or solid. .
Solar energy is also absorbed by the Earth's hydrosphere and Earth's atmosphere to produce meteorological phenomena containing exploitable forms of energy reserves. The Earth, in this energy model, resembles the water heater of the early heat engines, converting the heat absorbed from the Sun's photons into the kinetic energy of the currents of water, steam and air. , and alter the chemical and physical properties of these flows.
The potential of rainwater can be stored in dams and run the generator of hydroelectric plants. One form of making use of the energy from rivers and streams that existed before hydroelectricity was the water mill. The currents of the sea can also move the generator of a power plant using the currents of the sea.
The flow of the air, or wind, can generate electricity by turning a wind turbine. Before wind power generators were introduced, windmills were used to grind grain. Wind energy also causes wave motion across the sea surface. This movement can be utilized in power plants using waves.
Oceans on Earth have a greater specific heat than air and therefore change temperature more slowly than air when absorbing the same heat of the Sun. The ocean is hotter than air at night and colder than air during the day. This difference in temperature can be exploited to run heat engines in power plants that use the heat of the sea.
When the absorbed heat from the Sun's photons evaporates the seawater, some of that energy is stored in separating the salt from the salt water of the sea. The power plant uses the reaction of fresh water - salt water reclaim this energy when it brings fresh water from the river back to the sea.
ko thể tái tạo lại được sau khi đã sử dụng
nếu như dùng lãng phí quá thì nguồn năng lượng ko tái tạo sẽ vĩnh viễn "bay khỏi trái đất"
đắt, làm ô nhiễm môi trường
n our daily life, energy play a very important role, so we should save energy. I think there are many ways to save energy and now I will share with you some ways to save energy effectively. Firstly, we should turn off all the electric appliances when we don't use them such as: lights, fans, air conditioner...… Secondly, we can use solar energy or wind energy instead of electric energy in our house. It will help us save more money. Thirdly, we can go to school or go to work on foot, by bike or by public transport instead of motorbike or car. By these ways, the energy will be saved.
Bài dịch
Trong cuộc sống hằng ngày của chúng ta, năng lượng đóng một vai trò vô cùng quan trọng, vì thế chúng ta nên tiết kiệm năng lượng. Tôi nghĩ có nhiều cách tiết kiệm năng lượng và bây giờ tôi sẽ chia sẻ với các bạn một số cách tiết kiệm hiệu quả. Đầu tiên, chúng ta nên tắt tất cả những thiết bị điện khi không sử dụng như đèn, quạt, điều hòa…. Thứ 2, chúng ta có thể sử dụng năng lượng mặt trời hay năng lượng gió thay cho điện ở trong nhà của chúng ta. Nó sẽ giúp chúng ta tiết kiệm được rất nhiều tiền. Thứ 3, thay vì đi ô tô hay xe máy, chúng ta có thể đi bộ đi học hoặc đi làm. Bằng những cách này, chúng ta có thể tiết kiệm được rất nhiều năng lượng.
With fast growth of civilization there is also an ever mounting need for energy. Energy may be in the form of fuels or electricity. Petrol is a liquid fuel which is used widely nowadays. But this kind of fuels is likely to be exhausted at the rate man is using it recently.
To meet the challenge, various methods have been suggested. One is to minimize the man’s demand in using the energy. Non-essential consumption should be minimized. During certain days of the year, people all over the world turn off the electricity for 1 hour to save the energy. Modern gadgets consuming energy should only be used when they are absolutely necessary.
Energy conservation is possible through modernization of plant and equipment. People should replace the obsolete equipment by the modern ones.
Energy can be saved on transport by the following methods. People should commute by the rail rather than by cars and vans. The transport must be improved with a view to sparing the energy. Cities must be planned in such a way that the commuting distance from this place to others is minimized.
In industry, many things could be done to reduce waste of energy or to economize energy. The machine maintenance needs to be tightened; heater must be utilized properly. When systems are streamlined, economy in fuel is obvious. Instead of using materials requiring higher energy, those which require lower energy should be used.
We hope man with his ever rising urge for existence will cope up with this urgent problem and find alternatives.
Cho bạn nào có câu hỏi giống mình mà vẫn chưa tìm được câu trả lời. Solar energy brings us both benefits and drawbacks. One of the biggest advantages is that it is a renewable energy source. Energy can be produced as the sun lasts forever. Therefore, solar energy can really be called as a long- term energy source. Furthermore, that is a non- energy source of pollutants such as zero carbon dioxide or other gases in electricity generation. Beside those benefits, solar energy also has some drawbacks. The initial installation cost of solar cells is quite high, so not all people can use it. Also, it can not effectively work in cold weather due to the scarcity of sunlight. In conclusion, we can't deny the advantages of solar energy, but it still exists some disadvantages.
We need energy to live and work. Our major source of energy is oil. Oil is one kind of fossil fuel. The amount ot fossil fuels in the world is limited. Therefore, we must save it, and at the same time, we must find new sources of energy. Geothermal heat and nuclear power are alternative sources of energy. They can give us electricity. Other alternative sources are the sun, waves and water. These sources are not only unlimited and available but also clean and safe for the environment. People should develop and use them more and more in the future.
Coal is a combustible black or brownish-black sedimentary rock usually occurring in rock strata in layers or veins called coal beds or coal seams. The harder forms, such as anthracite coal, can be regarded as metamorphic rock because of later exposure to elevated temperature and pressure.
Coal gasification can be used to produce syngas, a mixture of carbon monoxide (CO) and hydrogen (H2) gas. . The use of coal as fuel causes adverse health impacts and deaths. Coal mining and coal fueling of power station and industrial processes can cause major environmental damage.
Nowadays, energy is being run out more and more so it is one of the most important things of our life. We need to save energy because nobody of us can lives without energy. So why don't we start to do it right in our home? We have many ways to save energy in our home. One of those ways is using electricity, water and gas economically. Such as we should turn off the light in room when we go out or in unnecessary situations, avoid wasting water, shut the kitchen stove when stop cooking. Use a microwave instead of a stove to reheat food. Use rechargeable batteries instead of disposable batteries... Besides, we should use electrical equipments which are energy - saving. Such as using lights and fans that have low capacity, or using equipments which reserve electricty. Not only do these help us to save money but also they work effectively.
In addition, we should frequently check electrical equipments in our home in order to fix opportunely. In summary, we need to save energy so that energy isn't run out and continues to serve human's life.
Đoạn văn này nói về việc tiết kiệm năng lượng ở nhà , coi như có bảo vệ năng lượng nhé !
Nowadays, energy is being run out more and more so it is one of the most important things of our life. We need to save energy because nobody of us can lives without energy. So why don't we start to do it right in our home? We have many ways to save energy in our home. One of those ways is using electricity, water and gas economically. Such as we should turn off the light in room when we go out or in unnecessary situations, avoid wasting water, shut the kitchen stove when stop cooking. Use a microwave instead of a stove to reheat food. Use rechargeable batteries instead of disposable batteries... Besides, we should use electrical equipments which are energy - saving. Such as using lights and fans that have low capacity, or using equipments which reserve electricty. Not only do these help us to save money but also they work effectively.
In addition, we should frequently check electrical equipments in our home in order to fix opportunely. In summary, we need to save energy so that energy isn't run out and continues to serve human's life.