Technology for solar energy use
Solar energy is a primary source for other sources of RES. To utilize this energy the following technologies are employed:
The technology “ Tandem Cell”
Large amounts of hydrogen are required to ‘feed' the ” hydrogen cells”. Until now the only way for it to be produced was by electrolyses. However, the British company “Hydrogen solar” considers that the photo electrochemical method is much more efficient. The company has developed “Tandem Cell” technology, in which the production of hydrogen is generated by a group of special solar panels.
The first layer is half transparent and it absorbs ultraviolet and blue rays. Using a nanokrystal layer of metal oxide a couple “electron-hole” is generated. The rest of the spectrum (green, red, infrared rays) goes through to the second panel. The two panels are connected with conductors in a special scheme. They together generate electricity capable of discomposing water to its substantial elements hydrogen and oxygen. Water is a thin layer between the two panels.
The authors estimate the KUA of the process to be 8 %. The experiment site with an area of 65 sq.m, working in Hydrogen Solar, produces kilos of hydrogen every day.
Scientist claim that if the KUA of the process is improved up to 10% and a roof of a garage is covered with such panels, then the annual production of hydrogen would be enough to run a car from 1700 km per year.
Photocells directly transform solar light into electric energy. They comprise different semi conductive materials, which after being irradiated with light transform it into mechanic or electric energy.
Over 95% of all photocells, produced by now consist of the semi-conductive material-silicon. As it is one of the most widespread materials on earth, this additional process is not detrimental to the environment.
An individual photocell usually generates between 1 and 2 watts. Cells are connected in big photovoltaic panels with power of 10 to 30W.
They are used to provide hot water and for heating of buildings. The cheapest models look like unfolded pipe system on the roof of the building, which directly absorb solar heat and transfer it into the house. These collectors can only be used in the summer, because they have the disadvantage of radiating heat back to the atmosphere. This problem is solved by the introduction of vacuum pipes for insulation.
Active solar collectors that use the principle of the thermo pump have already been developed. They work also in wintertime when the temperature of the surrounding air is below 0 degrees C. See diagram below:
Can I apply solar technology in my company?
The answers of the following questions will let you know, whether solar technology is appropriate for your company.
Is the building appropriate for PN panels installation or passive solar collectors?
To use a full capacity of your solar system, Solar modules should have a clear “view” to the sun for the greater part of the day or the whole of it, without being shaded by trees , chimneys, buildings, and other components of your building. This overshadowing can reduce the system efficiency significantly.
Does the chosen place have suitable orientation to the Sun?
The orientation of your solar system (the direction, that your system is facing), will affect the performance. Usually the best place for a solar system is a roof, facing south but also roofs facing east or west can be used. Flat roofs are also suitable because PH panels can be mounted, facing the sky or mounted on frames, inclined to the south, at the optimal angle.
Is there enough space on your roof or in your property?
Physical size of the solar system and the required area for its installment is determined by the required amount of energy.
If you establish after your first estimate that it is appropriate, then the selected distributor of solar systems, will have the necessary equipment to choose the particular site and technology.
If your roof is not appropriate and does not have the required area or does not face the Sun, you can mount the solar system on frames on the ground.
Another opportunity is to install the system as part of a construction such as covered parking or to provide shadow like an awning above a window.
The technology of “Tandem cell” is in a process of development and it is more a future vision, rather than a viable alternative for today.