What is photovoltaïc energy ?
It is the energy which results from the conversion of the energy of the sun rays (photons) in electrical energy (electrons), thanks to an intermediate material, the silicon. The silicon comes from some sand and is thus available in great quantities. It constitutes the basic material of solar panels and exists under two forms: the crystalline silicon and the amorphous silicon. Each of these two technologies has specific caracteristics :
Solar panels in the crystalline silicon have the highest efficiency (between 15 % and 20 % according to the technologies and the manufacturers) and the longer life cycle: 20 - 25 years of guaranteed power production. Their robustness is also considerable concerning the small portable solar panels. A single inconvenience: their slightest performance by cloudy weather.
Solar panels in the amorphous silicon have an efficiency lower than the crystalline solar panels and a life expectancy generally of 15 years but they are the most successful by overcast weather. They are adapted to regions receiving an annual moderate period of sunshine.
The energy produced by solar panels depends on the level of period of sunshine of the zone in which they are implanted. Solar panels must be arranged so as to get the maximum of direct bright radiation. They will have to be thus always directed to the course of sun, worth knowing southward in the hemisphere the North and northward in the southern hemisphere. Their efficiency will be maximal by giving them a slope equivalent to the latitude of the place where they are (ex: 45 ° in France), so as to get the beams of the sun perpendicularly in the solar panel. Solar panels do not need maintenance if it is not a simple cleaning to remove dusts and continue to get the maximum of light.
DEL lighting
The DEL (Light-emitting diodes) are semiconductors capable of producing light. Their big advantages are very low electric consumption,excellent shock resistance and very long-lasting of life (till 50 000 hours). Their efficiency did not stop progressing these last ten years, that is they succeed in shining more and more with less and less energy. They are so ideal light sources for photovoltaic plants.
Batteries
In the case of solar lamps SOLTYS, it is about 3 accumulators Ni-MH AA, called collectively rechargeable batteries. These accumulators present numerous advantages: big efficiency (maximum of energy in a minimum of volume), important longevity (recharging until 1000 cycles), environmental low impact (recyclable, without heavy metals), functioning including in hot atmosphere (until 55°C). Their use strengthens at the same time the performances and the ecological interest of the solar lamp SOLTYS.
How to optimize the life expectancy of accumulators Ni-MH ? An other advantage of the Ni-MH batteries is not to have "memory effect ". That is they can be reloaded at any time, independently of their level of discharge. It is only at the time of the first uses that it is important to wait for the low level before proceeding to the complete recharging of the lamp.
Do accumulators pass off when they are not used ? As all the batteries, the accumulator Ni-MH pass off gradually if they remain unused. It is however necessary to count 2 in 3 months. This phenomenon is called the autodischarge and we selected a quality of battery with low autodischarge to limit this phenomenon.
Advise for 12V and 230V solar kits
The solar energy is a source of electricity which allows to become autonomous wherever we are. However, to obtain a reasonable budget solar equipment, it is imperative to optimize its electric consumption, firstly by choosing electric devices with low consumption then by managing their durations of ignition to avoid the wasting. With similar electric equipments, the electric consumption can easily vary of the simple to the double according to the choice of energy electric performance of devices.
