Types of solar panel systems
|1. Solar panels: produce direct current
2. Switch board: the outlets of the solar panels are connected here
3. Inverter: transforms direct current into alternating current
4-5. Bidirectional meter: meters the quantity of energy for own consumption and fed back into the grid
The elements of an off-grid system are the solar panels, the charge controller, the battery(ies), the local consumers and the wiring. The electricity is generated in the solar modules and stored in the solar batteries. The consumers are supplied through the charge controller with 12 V, 24 V or 48 V DC direct voltage. If necessary, the charge controller can be supplemented with an inverter to supply the consumers using 230V alternating current. The advantage is that it also provides energy in locations which do not have an electricity network (farm, cottage, lodge).
|1. Solar panels: produce direct current
2. Charge controller: the energy produced in batteries via the charge controller. It protects the batteries from overcharging
3. Battery: the energy stored in it can be directly used to operate direct current consumers
4. Inverter: transforms direct current into alternating current
There are three types of solar panel technology widely available on the market: monocrystalline, polycrystalline and thin-film (amorphous) silica. Generally speaking, the efficiency and lifetime of the first two are better than those of the latter, while the latter is cheaper and less sensitive to environmental effects. If you can provide optimum positioning for the panels and are planning for long term, i.e. you want an investment which pays off, we recommend using mono- or polycrystalline solar panels. Due to their longer life and improved efficiency, they allow a more economical use of space.
What kind of solar panel technology to choose?
Single- or three phase systemIn the case of single-phase consumer connections, a generating device of up to 5 kW can be connected to the network, if the output of the phase allows it (25A). In the case of three-phase consumer connection, the equipment for producing can be connected to one, two, or three phases up to the available capacity, with a maximum of 50 kW. In this case, single-phase equipment can be connected up to 2.5 kW without network inspection. The network operator approves the single-phase connection of generation units with a nominal output of between 2.5 and 5 kW taking into account the network parameters and subject to the conditions laid down in the technical and economic information issued in response to the connection claim.
Optimum solar panel placementAt our latitude, the optimal angle is usually 35-40 degrees to the horizontal in case of southern orientation. It is easy to see that there is no single ideal angle all the time, since the orbit of the Sun is lower in winter than in summer, while we size our system for production throughout the year.
The best solution is a system combined with a Sun-tracking device, however, the extra return does not necessarily cover the significant extra costs. You can use devices turning on one or two axes in order to increase the return of the solar panels. These solutions are always automatic and have a number of implementation methods. A single-axis system can produce about 20-25% more yield, while a double-axis system is expected to give 35-40% more. The presence of the rotator device also has a number of disadvantages: it is maintenance-intensive, contains moving parts (possibility of failure), costly to implement, is sensitive to the natural effects (wind, rain), and it requires power to operate it. In view of the above, and taking into account the ever cheaper panel prices, it can be said that it is not worth installing rotating devices with the present off-take subsidy in Hungary (more precisely, the lack thereof), as it significantly extends the recoup period of the system.
A solar panel is a physically emission, noise- and odour-free device, which doesn't disturb those living in its environment and can only be objectionable in the aesthetic sense.
Evolution of the output of the system based on the angle and orientation:
In addition, the annual production of the solar panel system is also influenced by the topology and the wiring of the system, the efficiency of the inverter, shadow effects, ambient temperature and, obviously, the intensity and duration of the sunlight.
A solar panel system of 1 kW nominal capacity can produce approx. 1100-1150 kWh of electricity a year.