Very unfortunately, nearly all of the energy sources in Hong Kong are non-renewable, and they will run out in the future.
How non-renewable energy generate electricity
Fossil fuel
Fossil fuel is used indirectly to produce electricity. Fossil fuel is burnt to heat water in a boiler and convert it to steam which inturn rotates a turbine like in windmills. This turbine is attached to a generator which is used to generate electricity.
Nuclear
Nuclear power is a power produced from controlled . Commercial plants usually use nuclear fission reactions of uranium atoms. As an electron bombards with a uranium atom, it will split into two other atoms and the reaction produces a large amount of energy. Electric utility reactors water to produce steam, which is then used to generate .
Problems of non-renewable energy
Fossil Fuel
Burning fossil fuels is responsible for environmental problems such as greenhouse gas accumulation, acidification, air pollution, water pollution, damage to land surface and ground-level ozone. These environmental problems are caused by the release of pollutants that are naturally present in fossil fuel structures, such as sulphur and nitrogen.
- Global warming
When these fuels are burned, they produce the gas carbon dioxide, which is a greenhouse gas and is a major contributor to global warming. The burning of fossil fuels increases the carbon dioxide concentration in the atmosphere and hence enhances the greenhouse effect, resulting a gradual rise in global temperature, known as global warming.
Currently, oil burning is responsible for about 30% of all carbon dioxide emissions to air. Natural gas does not release as much carbon dioxide because of its methane structure. The largest emissions are cause by coal combustion.
- Acid rain formation
Burning of coal with high sulphur content will produce sulphur dioxide. Sulphur dioxide will harm human’s respiratory system. When the gas dissolves in rainwater, acid rain will form. Acid rain affects marine lives and affects plants growth. It also attacks buildings and statues made from calcium carbonate.
- Smog
Burning coal without first purifying it contributes to the production of smog (smoke and fog). It affects health my irritating our respiratory system and eyes, and cause headaches
- Water pollution
The use of fossil fuels will cause pollution of water. Oil spills causes great harm to the environment. Most birds affected by an oil spill die unless there is human intervention. Marine mammals exposed to oil spills are affected in similar ways as seabirds. In addition, because oil floats on top of water, less light penetrates into the water, limiting the photosynthetic rate of marine plants and algae. Population of aquatic animals hence decreases. The ecosystem will be affected.
- Other problems arising form using non renewable energy
Coal may result in underground fires that are virtually impossible to extinguish. Coal dust can even explode. This makes coal mining a very dangerous profession.
Nuclear Energy
The waste from nuclear energy is extremely dangerous and it has to be carefully looked after for several thousand years. The possibility of accidents happening can’t be overlooked. When there is an accident of the power plant, radioactive substances in the plant will cause serious unpredictable health problems to humans.
Types of renewable energy
Solar energy
The solar panel collects the sun's heat, absorbs the heat and transfers it to fluid within the engine. The heat causes the fluid to expand and produce mechanical power. The mechanical power is then used to run a generator or alternator to produce electricity.
Biomass
Biomass energy technologies refer to those technologies using nutrients in the plant matters or animal wastes to produce electricity. Biomass energy is considered as renewable energy because the energy content of plant matters originated from the solar energy absorbed during photosynthesis.
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Wind energy
The blade of the wind turbine acts like an airplane wing. When the wind blows, the blade will rotate and cause the rotor to spin. This provides mechanical energy for generating electricity.
Problems of renewable energy
Solar Power
Building and installing solar heating panels are costly. As sun doesn't shine all the time, it is an unstable energy sources. To store up the energy, large heat storage tank is required which is costly.
Wind Power
Wind blows in an unpredictable manner which gives an unstable power supply.
A large number of windmill is need to supply sufficient energy. It is only suitable for places of high altitude.
Biomass
The cost of producing energy from biomass is higher due to the special design of the boilers to facilitate combustion of biomass.
Types of renewable energy suitable for remote places
Wind energy
Wind energy is a cheap and easy way to install wind turbines in remote area. It is suitable for small-scale electricity production. Little facilities are enough for providing electricity to isolated and remote locations. It also reduces the dependence of the locations on fossil fuels.
Solar energy
The energy and heat from the sun is free. Once solar panels or solar thermal collectors are set up, there are no electrical expenses necessary to power them. Solar cells require very little maintenance, greatly because there are no moving parts that must be maintained. Therefore, solar cells can last for a very long period of time. Solar power is incredibly versatile. A variety of inventions may be powered by it, including cars, water heaters, fountains, buildings, and satellites. In remote locations, solar power may be a more realistic energy option than running large lengths of electrical wires to connect to a grid.