The advantages and disadvantages of solar energy refer to the benefits and risks of using technologies to capture and use light energy from the sun.
Of all the solar energy that reaches the Earth
- 43% is used to heat the atmosphere and the soil;
- 35% is returned to space when reflected back to Earth;
- 22% is used in the water cycle: evaporation, precipitation and condensation;
- 0.2% is used in wind generation; and
- 0.02% is used by plants in the process of photosynthesis.
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Solar energy: advantages
1. Renewable energy source
The energy from the sun is unlimited in practical terms.
2. Alternative energy
Solar panels (photovoltaic systems) can be used in homes, industries and other facilities, reducing dependence on fossil fuel energy.
3. Diversity of applications
We can use solar energy for different purposes:
- to generate electricity: through photovoltaic systems (solar panels).
- to generate heat: through thermal systems, we use solar energy to heat water and facilities.
The applications depend on the technology involved.
4. Use of urban space
The installation of photovoltaic or thermal systems can be carried out on urban constructions, roofs of buildings and houses, making use of this space for the generation of electrical and/or thermal energy.
5. Low maintenance cost
The maintenance of solar energy collection systems is low once installed.
6. Technological development
The technological development of the solar energy industry is constantly advancing. One of the aspects to be improved is the manufacture of photovoltaic cells that are more economically attractive, more durable and more efficient.
7. Exploitation of desert regions
Deserts are considered unbearable regions, practically abandoned because of the difficulty of surviving when one is not adapted. Nevertheless, they are an excellent option for the use of solar energy throughout the year.
For example, A south American Solar plant comprises 776,000 photovoltaic modules that cover an area of 280 hectares in Chile’s Atacama Desert. This plant, with a capacity of 246 MWp, produces energy equivalent to the consumption of 240 thousand homes and provides 100% of the energy required by Google’s data center in Chile.
8. Low emission of greenhouse gases
The electricity that is generated by solar energy is practically pollution-free when compared to fossil fuels. The emission of greenhouse gases is reduced for two reasons:
- Once installed, the operation of photovoltaic systems does not release greenhouse gases;
- By obtaining energy by this means, fossil fuels are being abandoned.
9. Availability worldwide and beyond
Solar energy is available all over the world: the sun illuminates every corner of the Earth. Even in outer space. For example, the solar arrays on the International Space Station provide all the electrical power required by the members of the various expeditions.
10. Access to electricity in remote locations
In some places where access to the public electricity grid is restricted, the use of PV systems is an acceptable option. For example:
- to run irrigation systems in the fields,
- for ground track lighting,
- to set up emergency call boxes on the highways,
- for navigation systems and buoys,
- to run hydraulic pumps, and
- for electric fences.
You may be interested in renewable and non-renewable energy.
Solar energy: disadvantages
1. Large areas of land
The technology to collect and produce electricity on a large scale from solar energy requires large areas of land, so it would compete with land for agriculture or forests. For example, the El Romero Solar plant comprises 776,000 photovoltaic modules covering an area of 280 hectares in Chile’s Atacama Desert.
2. High investment cost
The initial purchase investment of the photovoltaic system is high, as it requires, apart from the photovoltaic modules, the inverter, the charge regulator,. the wiring, the batteries and the installation.
3. Depending on the climate
On cloudy and rainy days the efficiency of solar energy collection decreases considerably. For example, on a bright summer day you can get 10 kilowatts per hour per square meter; on the rainiest winter days it does not exceed 1 kilowatt per hour per square meter.
4. Variability of sunlight
The angle at which sunlight strikes a particular region varies throughout the day. In fixed solar energy collection equipment, it is difficult to make the most of solar energy throughout the day.
Sunlight also varies with the time of year. For tropical countries, the number of hours of light is approximately the same throughout the year; however, countries in temperate zones receive fewer hours of light during autumn-winter.
5. Population centres far from power generation centres
Ideal production sites, such as deserts, are located far away from large population centers. Although these sites provide the most efficient generation of energy, the distribution of this energy to consumers presents a logistical problem. For example, A South American solar plant, in the Atacama Desert in Chile, is located 645 km from the capital, Santiago.
6. Disposal and recycling of toxic materials
The biggest environmental problem associated with photovoltaic systems is the use of toxic chemicals such as cadmium sulfide and gallium arsenide in their manufacture. These chemicals are highly toxic and persist in the environment for centuries, so disposal and recycling of these materials in disused cells is a serious problem.
7. Low energy production efficiency
Of all the solar energy that reaches the photovoltaic panels, on average only one fifth is transformed into electricity. Although it is possible to increase efficiency with different materials, the economic cost is very high. However, efficiency cannot exceed 30% due to the physics of current technologies.
8. Affected by air pollution
Air pollution, smog and dust interfere with light transmission. Thus, in cities with significant air pollution, the efficiency of solar panels will be reduced.
9. Depends on backup systems
To maintain current power consumption levels, a backup system is required:
- a storage system, such as batteries, to store energy when there’s sunshine and use it when there’s no sunshine.
- Backup systems: either using an electric generator or connected to the city’s conventional electric system.
10. Lack of information and technical support
The lack of information at the public level regarding the operation and productivity of electricity power generation systems is reflected in the fact that few companies are dominant in the systems market.
If any equipment or solar panels are damaged, individual users rely exclusively on the technical support of the selling companies, whose technical knowledge is very limited.