Solar energy
Is the energy directly from the sun, especially in the form of light. When the Earth orbits the sun, it receives 1400/W/m2. 20% is absoved by the atmosphere and 40% is reflected by the clouds. The other 40% can be used as thermal or photovoltaic energy.
Solar photovoltaic energy
is the conversion of the sunlight into electricity by the photovoltaic effect. This is the chemical reaction to the exposure of the photovoltaic cells to the solar energy . When the photons in the sunlight hit the solar panel, they are absorbed by semiconducting materials, such as silicon. Then the electrons are knocked loose from their atoms, allowing them to flow through the material to produce electricity.
Applications of solar photovoltaic energy
All products, which are operated by electrical energy, can use solar photovoltaic energy. Small objects and even big photovoltaic power stations, which can provide electricity to a village, can be connected to a power grid or be independent from the power grid.
Applications of solar thermal energy
It can be used to heat household water, swimming pools water or residential and industrial buildings.
Diference between systems with or without power grid
Off-grid systems, or isolated systems, are constituted by batteries. They store the photovoltaic energy which can be used when the energy production is not enough.
The power grid systems provide all the necessary energy to the system and they also resort to the same grid when the energy production is not enough.
Elements of the photovoltaic system with power grid
These systems are constituted by: photovoltaic modules, an invertor and /or a regulator, a fixation structure and the electrical components (electrical panel, electrical cables, circuit breaker, fuses, plugs and sockets and switch .)
Elements of an isolated system
These systems are constituted by photovoltaic modules, an invertor and / or a regulator, batteries, a fixation structure, electrical components: (electrical panel, electrical cables, circuit breaker, fuses, plugs and sockets and switch .)
Photovoltaic modules
A photovoltaic module or a photovoltaic panel is a packaged interconnected assembly of photovoltaic cells. They increase the input offset and the output voltage, creating more energy.
Amorphous Silicon Module
An amorphous silicon module is constituted by amorphous silicon cells, which have a disordered nature of the material. This module has got a low cost production but it has got an inferior efficiency with conversion losses in the first year.
Single Crystal Silicon Module
This module is constituted by single crystal silicon cells, which structure is one of the most purest: about 98%. These modules are more efficient and they can achieve 18%. These modules are the most installed ones but they are also the most expensive due to their strict preparation process.
Polycrystalline Silicon Module
This module is constituted by polycrystalline cells which demand a less strict preparation process than the single crystal silicon cells. This module has got a low cost production. Its efficiency is also inferior, 12,5%.
Photovoltaic installation in domestic buildings
A photovoltaic installation in domestic buildings always requires a preexisting connection to the power grid. It must also be connected by cable to the supply power of the building.
Necessary construction work in order to install the photovoltaic panels
The photovoltaic panels can be easily incorporated either into flat roofs, pitched roofs or on the ground. In pitched roofs, the structure will be fixed to the roof structure. In flat roofs, the structure will be fixed to the flat structure without spoiling it. On the ground, a special structure will be needed . The electrical cables go from the panel surface to a cable. It is not necessary any construction work.
Where can you connect the photovoltaic installation?
A photovoltaic installation in domestic buildings is connected to the domestic electrical panel.
When the aim is selling energy to the power grid, it is necessary a specific electrical panel which saves the amount of energy transferred to the grid. This specific electrical panel saves not only the amount of energy supplied to the grid but also the amount of energy which is debited to the power grid. This specific electrical panel will be near the domestic electrical panel, giving an easy access to the electricity operator.
Durability of the off-grid photovoltaic equipments
The off-grid photovoltaic equipments have the same durability as the power grid equipments. The only diference is that the batteries, which store the energy, will last
5 to 10 years.
Necessary maintenance to the photovoltaic systems
These systems require a preventive maintenance. It should be done twice a year, when the season changes. This avoids the modules profit loss and it extends its durability.
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