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 reaching the Earth:
- 43% is used to heat the atmosphere and the ground;
- 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; i
- 0.02% is used by plants in the process of photosynthesis.
|For the environment||
|For the planet||
Solar energy: advantages
1. Renewable energy source
The energy from the sun is limitless in practical terms.
2. Energy alternative
Solar panels (photovoltaic systems) can be used in homes, industries and other facilities, so that dependence on energy from fossil fuels is reduced.
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, solar energy is used to heat water and facilities.
Applications depend on the technology involved.
4. Taking advantage of urban space
The installation of photovoltaic or thermal systems can be done on urban constructions, the roofs of buildings and houses, which makes use of this space for the generation of electrical and/or thermal energy.
5. Low maintenance cost
The maintenance of the solar energy collector systems is under once installed.
6. Technological development
The technological development of the solar energy industry is in constant progress. One of the aspects to be improved is the manufacture of more economically attractive, more durable and more efficient photovoltaic cells.
7. Utilization of desert regions
Deserts are considered unbearable regions, practically abandoned due to the difficulty of surviving when one is not adapted. However, they are an excellent option for the use of solar energy throughout the year.
For example, the El Romero Solar plant in the Atacama desert in Chile produces equivalent energy for the consumption of 240 thousand homes and provides 100% of the energy required for Google’s data center in Chile.
8. Low emission of greenhouse gases
The electricity 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, we are ceasing to use fossil fuels.
9. Availability worldwide and beyond
Solar energy is available worldwide: the sun illuminates every corner of the Earth. Even in outer space. For example, the solar arrays of the International Space Station provide all the electrical energy 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 photovoltaic systems is an acceptable option. For example:
- to operate irrigation systems in the fields,
- for road lighting,
- to operate emergency call booths on motorways,
- for navigation systems and buoys,
- to operate hydraulic pumps, i
- for electric fences.
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Solar energy: disadvantages
1. Large areas of land
The technology to collect and produce large-scale electricity from solar energy requires large tracts of land, so it would compete with land for agriculture or forests. For example, the El Romero Solar plant comprises 776,000 photovoltaic modules that cover an area of 280 hectares in the Atacama desert, in Chile.
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 capture decreases considerably. For example, the rainiest days of winter generate less than a tenth of what can be obtained on a radiant summer day.
4. Variability of sunlight
The angle at which sunlight hits a particular region varies throughout the day. In solar energy collection equipment that is fixed, it is difficult to make the most of solar energy throughout the day.
Sunlight also varies according to 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 centers far from power generation centers
Ideal production sites, such as deserts, are far from large population centers. Although these places provide the most efficient energy generation, the distribution of this energy to consumers presents a logistical problem. For example, El Romero Solar, in the Atacama Desert in Chile, is 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 locating and recycling the cell materials is a serious problem.
7. Low energy production efficiency
Of all the solar energy that reaches the photovoltaic panels, on average only a fifth is transformed into electricity. Although it is possible to increase the efficiency with different materials, the economic cost is very high. However, the efficiency cannot exceed 30% due to the physics of current technologies.
8. Affected by air pollution
Air pollution, smog and dust interfere with the transmission of light. Thus, in cities with noticeable air pollution, the efficiency of solar panels will be diminished.
9. Depends on back systems
To maintain current electricity consumption levels, you need a back-up system:
- Storage system: as batteries, to store energy when the sun is there and use it when the sun is not.
- Backrest systems: either using an electrical generator or connected to the city’s conventional electrical system.
10. Lack of information and technical support
There is a lot of ignorance about how solar powered power generation systems work and how much they produce. This is reflected in the fact that few companies dominate the systems market.
If any equipment or solar panels are damaged, private users are solely dependent on the technical support of the sales companies, whose technical knowledge is very limited.
You may also be interested in seeing:
DeGunther, R. Alternative Energy for Dummies. Wiley Publishing. 2009