Traditional Energy Versus New Energy

Traditional Energy Versus New Energy


The energy produced and used in human society mainly comes from fossil fuels, such as oil, coal, natural gas, and nuclear fuel. Nuclear energy is a conventional energy source in developed countries like Japan. It is considered unconventional energy in China because it is not widely used. Fossil fuels are the basis for leading people into the industrial age and modern economic development, but the consumption of these energy sources cause significant deterioration of the ecological environment. For example, in terms of power generation, the most commonly used fuel in China is coal, which is used for thermal power generation. Data shows that for every 1 kWh of electricity generated by thermal power in China, 1.07 kg of carbon dioxide, 9.93 g of sulfur dioxide, 6.46 g of nitrogen oxides, 1.55 g of carbon monoxide, and a large amount of smoke and heavy metal pollutants are released. These substances are the main factors causing the greenhouse effect and acid rain. Nuclear power seems to be clean and pollution-free, but once a nuclear leak occurs, it can seriously affect the surrounding environment and cause the death of a large number of living things, as seen with the Chernobyl Nuclear Power Plant in the former Soviet Union and the Fukushima Nuclear Power Plant in Japan.
 
Traditional energy sources not only cause significant damage to the environment, but these non-renewable energy resources are now facing exhaustion due to long-term over-exploitation. Given that traditional energy sources are highly polluting and unsustainable, developing clean renewable energy is the only path to sustainable development. New energy sources include solar power, hydropower, wind power, and biomass energy. Among them, hydropower generation causes little pollution, but its limitations are also very obvious: it floods a large area of land, causing ecological damage, and China's hydropower resources are limited. Additionally, it is affected by seasonal variations. If a reservoir collapses, it will cause serious losses. Wind power generation can directly use wind, making it suitable for use in open areas but it requires a large area for system construction. It is affected by geographical location and wind speed, and its conversion efficiency is not high. The cost of using biomass energy is very high, and its scale of development is not large. As a form of renewable energy, solar energy has the following advantages compared with other types: it has the most abundant resource reserves, is the cleanest and safest in terms of usage, and it is currently developing very rapidly. Solar power can be converted into electrical energy and thermal energy through specific methods. The method of converting solar power to electrical energy is called photovoltaic power generation, and the technology of converting it to thermal energy first and then generating electricity from thermal energy is called solar thermal power generation. Among these, photovoltaic power generation is currently the most widely used form.
 
Looking around the world, the photovoltaic industry entered a period of rapid development in the 1990s. The United States proposed the Million Roofs Plan in 1997, and Japan launched the New Sunshine Plan in 1992. By 2003, Japan's photovoltaic module production accounted for about half of the world's total, and four of the world's top ten solar manufacturers were from Japan. Germany's new renewable energy law stipulates the on-grid electricity price for photovoltaic power generation, which significantly expanded the photovoltaic market and promoted the development of the entire photovoltaic industry, making Germany the fastest-growing country in the world in photovoltaic power generation after Japan. The output of solar cells increased from 125.8 MWp in 1997 to 4000.05 MWp in 2007. In terms of installed capacity, development was extremely slow before 2002, reaching only about 2.6 GWp in 2007. In recent years, it has developed rapidly, reaching 68.1 GWp in 2011 and 96.5 GWp in 2012. In 2012, the European market accounted for 59% of the installed capacity, making it the main consumer region. Germany ranked first in the world with an additional installed capacity of 7.6 GW, while China ranked second with at least 3.5 GW.
 
The solar radiation absorbed by China's land surface each year is equivalent to 4.9 trillion tons of standard coal, which is equivalent to the power generation of tens of thousands of Three Gorges Dams. In recent years, China's photovoltaic industry has developed rapidly. In 2007, China's solar cell production was about 1180 MW, while Europe, Japan and the United States produced 1062, 920, and 266 MW, respectively, indicating that China has become the world's largest solar cell producers. Since 2000, China's photovoltaic technology has been connected to the grid for large-scale power generation. The total installed capacity was 100 MW in 2007, 140 MW in 2008, 300 MW in 2009, 800 MW in 2010, 3.3 GW in 2011, and 7 GW in 2012. In 2009, China proposed the Golden Sun demonstration project, most of which consisted of power stations with an installed capacity of about 1 MW. These projects were divided into user-side grid-connected power generation projects, photovoltaic power generation projects in areas without electricity, and large-scale grid-connected power generation projects. User-side grid-connected projects accounted for 80.7%, with 222 projects covering most provinces and cities across the country. In 2012, the second Golden Sun demonstration projects were launched, with a total installed capacity of 2.83 GW. This time, they were mainly large-scale photovoltaic power stations with an installed capacity exceeding 10 MW.
 
Although most of the solar panels made in China are exported to Europe, their application in China is becoming increasingly extensive. China has a large market capacity. However, due to the high cost of photovoltaic systems, they are not widely used at present. It is believed that with further development of technology, reduction of production costs, and higher government subsidies in the future, photovoltaic power generation will further develop. 
 
Solar power generation has always been considered a clean and pollution-free energy source. During use, it only needs to absorb sunlight without consuming other energy and materials, nor does it release pollutants. However, it should be noted that the solar power generation system involves typical terminal environmental protection and process pollution. The terminal here refers to the use process, and the process refers to the manufacturing process. The most important component of the solar power generation system is the solar panel, which is obtained from mining raw materials, production, and processing. The whole process requires silicon purification, silicon crystallization or ingot casting, silicon wafer cutting, cell production, and assembly of solar panels. In these processes, not only do materials or chemicals cause pollution, but also a large amount of electricity used during the period is mainly supplied by the power grid, and the power generation process will inevitably cause pollution.
 
In addition, after the photovoltaic power station’s service life ends, post-processing should also be considered. Incineration or landfill of silicon and metals causes varying degrees of pollution to the land, water, and air. Therefore, we cannot conclude that solar power generation is absolutely pollution-free based solely on the non-pollution observed during the use phase. We should analyze it from a holistic perspective, considering the entire life cycle. Although solar power generation systems show significant advantages during the use phase, the environmental impact of their production and waste treatment processes cannot be ignored. Therefore, a comprehensive assessment of the environmental impact of solar power generation should start from the perspective of the entire life cycle, considering the pollution and resource consumption of each link, optimizing the production process, and improving the recycling rate to achieve true sustainable development.