Photovoltaic solar panels
The climate change and the global warming are facts that we must consider seriously to start chnage our way of life. We must stop using fossil fuel and other energies that are damaging the planet. For this reason, the renewable energies are the best solution although are still not much used around the world. The main objective in this assignment is explain clearly the solar energy and the benefits of using it instead of fossil fuel energy.
In this space I want to talk anout the solar energy panels which can provide energy to our buildings and make it more sustainable. Althought I advanced that their are not green at all.
First of all, there are two main types of solar energy technology:
1) Photovoltaic (PV) solar panels. These devices convert sunlight into electricity.
2) Solar thermal collectors use the same solar energy that photovoltaic panels do, but they generate heat instead of electrical power.
But, I want to focus this post explaining what exactly are the photovoltaic solar panels, what are the main applications, problems that we can find in these devices and finally the potencial of using solar energy.
Description of photovoltaic solar panels
These devices generate electricity directly from the sunlight via an electronic process that occurs naturally in certain types of material, called semiconductors. Electrons in these materials are freed by solar energy and can be induced to travel through an electrical circuit, powering electrical devices or sending electricity to the grid.
Here I attach a video which explains really clearly what the solar panels are, and how they work.
To understand how the photovoltaic panels works we should know they are formed from solar cells. And, depending on the amount of electricity needed we must combined some solar panels:
- Solar cells: Solar cells are the basic building blocks of all photovoltaic systems. They are made out of semiconductor materials such as silicon or gallium arsenide. When they are exposed to light they generate electricity through a process known as the photovoltaic effect.
- Solar panels: Although the solar cell is the basic element of a PV system, the primary component you will work with is the solar panel. When you specify your system, you won't be specifying solar cells, you'll be specifying solar power panels.
- Solar arrays: Two factors that will have an impact on your solar array design are the power density and size of your solar panel. Combined, these factors will determine the overall size of your solar array. Power density measures how much power your selected solar panel produces per square foot.
This picture shows the different parts that formed the solar panels.
Uses & Applications of photovoltaic solar cells
There are a lot of different products with photovoltaic cells to create electricity using the sunshine. They are used in isolated lamps in parks, in toys and electrical gadgets, camping equipment, to charge batteries for computers/phones, road signs, etc. But the main objective is to create electricity for the buildings. For that, the cells are found in different ways and sizes so they can be placed on the roofs, facades, windows, etc.
Solar panels can be found in small scale used by building/residences or families to produce their own electricity but there are also large electrical companies selling clean energy who own large surfaces full of photovoltaic solar panels.
Problems of photovoltaic solar panels
The main problem of these kind of renewable energies is the high costs. Although there are other problems that sum up to the expensive cost can be a decisive reason to not use the solar energy in our buildings.
1) Solar panels use expensive semiconductor material to generate electricity directly from sunlight. Semiconductor factories need clean manufacturing environments and are expensive to build and maintain.
2) The efficiency of solar cells currently ranges from around 20% up to a top range of around 40%, although this continues to improve. The rest of the sunlight that strikes the panel is wasted as heat.
3) Installing solar panels on a house is expensive and requires experienced people. These systems used fixed solar panels since alignment systems are too expensive for the average homeowner. The initial investment outlay is a significant facor in why there is a lack of support for solar power from consumers.
4) But these large, inexpensive tracks of lands are found far from cities where the power is needed. Expensive transmission lines are needed to bring the power the power to a distant market.
5) The maintenance is very important. The panels must be clean to operate at their most efficient way. Their efficiency drops drastically even when a small portion is blocked by fallen a film of dust.
6) Another important problem is the fact that the power production only takes place when the sun is shinning. When solar panels are not producing energy, it takes longer to recoup their installation and maintenance cost.
Although this renewable energy has some problems I think we must consider the benefits that it offers to the planet. Asking specialists in the field we can choose the perfect option for our home and reduce the existing problems at the minimum.
Possible solutions
1) Scientists need to discover more efficient semiconductors that are more efficient at electricity production. In that way, if more efficient panels are developed, less space will be required to produce the same amount of power.
2) Develop more efficient production techniques. Mass production of panels in efficient factories will help bring down production costs and make them cheaper for consumers to buy.
3) New transmission technology is needed to bring the clean energy to market. Energy storage systems will also help smooth out the production problems caused by climate and atmospheric interruptions.
Until all of these problems are being solved, the promise of pollution-free energy from the sun will continue to be only marginally used in our society.
Potential of using solar energy and photovoltaic cells
As is known the solar energy is an essential factor for the life. It is found in every place in the world and it should be free for everyone and to use it to produce the electricity in our home. For the reason, it seems unbelievable that we are wasting the solar energy and using other kind of energies which moreover are harmful for the humans and the planet.
- Can be used in homes industries and utilities
- The transmission costs are reduced ifi the panels are placed in roofs, façades, etc.
- Improved public health.
- Not harmful for the planet. Reduce the pollution emitted.
- Unlike fossil fuels it is an unlimited energy supply.
Permormance of the photovoltaic panels
After knowing better what the photovoltaic panels are I try to understand the performance of these panels First of all it could be easy to think that they are really efficient because we can find them in different formats and used in multiple applications. But actually the best photovoltaic panels are only working at 30-40% of their capacity so there is still a long way to go to make this technology really worthwhile. Behind this apparently green product there is a damaging process for the planet.
This is why it is important to analyse the performance of these panels taking into account other factors such as carbon footprint, ecological footprint, cost efficiency or modularity.
First of all, we can't say that photovoltaic panels are totally green because to produce them chemical solutions and fossil fuels are used. To understand exactly what the problems are, and how they might be addressed, it's helpful to know a little something about how photovoltaic panels are made.
The majority of solar cells today start as quartz, the most common form of silica (silicon dioxide), which is refined into elemental silicon. There's the first problem: The quartz is extracted from mines, putting the miners at risk of one of civilization's oldest occupational hazards, the lung disease silicosis.
The initial refining turns quartz into metallurgical-grade silicon, a substance used mostly to harden steel and other metals. That happens in giant furnaces, and keeping them hot takes a lot of energy. And also turning metallurgical-grade silicon into a purer form called polysilicon which creates the very toxic compound silicon tetrachloride. Although once constructed the solar panels produce clean energy the process of making them is not green at all.
However, the thin-film solar cells eliminates many of the environmental and safety hazards from manufacturing, because there's no need for certain problematic chemical such as hydrofluoric acid or hydrochloric acid. But that does not mean you can automatically stamp a thin-film solar cell as green.
Moreover, the modularity allows to create smaller or bigger surface with solar panels depending on the electricity requirements of the building. Using standard solar panels this work is fast and easy. The unique, modular relationship between solar cells, solar panels and solar arrays makes it possible to configure a system to meet most power and space requirements.
But all of this effort is useless if the demand of solar panels is not enough. Fortunately, it is supposed that the demand of solar panels in Europe increased approxmately about 15% in 2015. Knowing the necessity of leaving the fossil fuel and other polluting energy suppliers we could say that the renewable energies will increase their demand in the following years. And maybe that fact produces a price reduction in this field.
After investigating in this field I understand the great possibilities of this product but I have also seen the dark side due to it's production process. I think if this can be improved in the next years, photovoltaic solar panels will be one of the best power supplies that we can use, specially in countries like mine, Spain.
Since I have been living in Groningen I have realized how this energy is wasted in my home country. I see more solar panels in The Netherlands (where there is half as much sun) than in Spain.
