How to reduce CO2 emissions?
The CO2 emissions per kilowatt-hour of electricity produced by different countries vary greatly, depending on the energy structure used for power generation.
The countries with the highest CO2 emissions are mainly dependent on coal for power generation. Fossil fuels produce one-third of the world’s electricity and one-third of the world’s CO2 emissions. Nuclear energy and renewable intensive energy structures should be the most suitable low-carbon power generation methods. One option to reduce exhaust gas may be to reduce CO2 emissions.
Diversified fuels are critical to issues such as energy security, climate change, and sustainable development. In addition, the excessive dependence on non-renewable energy generation is not feasible in the long run. Therefore, the most important way to solve the energy crisis is to make extensive use of abundant renewable energy resources such as biomass energy, solar energy, wind energy and geothermal energy. Many countries have set ambitious goals for renewable energy. However, the problems related to renewable energy resources and the use of them for power generation are urgently to be solved. Are there enough renewable resources for the world’s energy and technology to produce electricity? How do we need to change our mindset to overcome planning and political obstacles? At present, some traditional renewable energy sources still account for the global renewable resources leading position. For example, hydropower and traditional biomass energy provide 6% and 9% of global energy demand, respectively. At present, only about 2% of the world’s main energy is provided by new renewable energy sources such as wind, solar, small or micro hydropower.
The sun is the source of all energy on the earth. In ancient civilizations like India, it was enshrined as a god. The direct energy of the sun is inexhaustible and constantly regenerating. Solar energy is a natural, free, abundant and available radiant energy; it does not require any input to receive solar energy, and no country has the right to completely control it. Both poor and rich countries receive the radiant energy from the sun equally.
Estimation of CO2 emissions
For sustainable development that does not endanger the climate, the future energy structure can be conceived as ① nuclear fuel intensive; ② natural gas intensive; ③ renewable energy intensive. The carbon dioxide emissions from the burning of fossil fuels in the energy mix can be analyzed with a simple technique. Although the results obtained are not absolutely correct emissions, because these data depend on fuel quality and preparation methods, the trend of the results is still trustworthy. The CO2 emissions contributed by the burning of fossil fuels are as follows:
Petroleum→260gCO2/kWh
Natural gas→195gCO2/kWh
Coal→30gCO2/kWh
Because 1toe (ton oil equivalent) is 11,600kWh, the CO2 emissions produced by the combustion of fuel per ton of oil equivalent are
Petroleum→3.01t CO2/toe
Natural gas→2.262t CO2/toe
Coal→3.828t CO2/toe
By changing the energy structure, CO2 emissions can be greatly reduced. It is worth mentioning that in the energy structure, any reduction in the proportion of fossil fuels means an increase in the proportion of renewable energy and nuclear energy. The reduction of the proportion of fossil fuels in the current (2008) energy structure is feasible, and CO2 emissions can also be controlled by changing the contribution of different fossil fuels. The positive increase in the proportion of renewable energy and clean fuels in the energy structure not only reduces dependence on foreign energy fuels, but also helps: ①improve energy security ②reduce CO2 emissions; ③reduce environmental pollution; ④reduce health concerns harm.
The future prosperity of mankind depends on how to successfully solve two major challenges, namely, ① ensuring the supply of reliable and economical energy, and ② adopting a low-carbon, high-efficiency, and environmentally sound energy supply system. In order to solve these problems, the focus should be shifted to finding energy that can greatly reduce CO2 emissions than fossil fuels, rather than saving existing energy. In this regard, clean energy such as renewable energy will be an important alternative energy source.
In order to ensure that the energy used is provided to consumers in the best structure, sustainable, abundant, economical, clean and green way, issues such as energy security, the use of alternative fuels, and the conversion technology between energy structures are crucial. Most of the technologies needed to convert fossil fuels into clean, renewable energy already exist. In addition, it can be seen that the conversion from fossil fuels to renewable energy is economically feasible from the mutual conversion of the energy structure of several countries. The use of renewable energy in the future energy structure can: ①abolish combustion as the usual way to generate electric energy and vehicle power; ②ensure energy security; ③improve the quality of life.