With the rapid development of distributing photovoltaic, more and more roofs are “dressed in photovoltaic” and become a green resource for power generation. The power generation of the PV system is directly related to the investment income of the system, how to improve the system power generation is the focus of the entire industry.
1. The difference in power generation of roofs with different orientations
As we all know, different orientation of photovoltaic modules receives the sun irradiation will be different, so the power generation of photovoltaic systems and photovoltaic module orientation has a close link. According to the data, in the area between 35~40°N latitude, for example, the irradiance received by roofs with different orientations and azimuths are different: assuming that the power generation of the south-facing roof is 100, the power generation of the east-facing and west-facing roofs is about 80, and the difference in power generation can be about 20%. As the angle shifts from due south to east and west, the power generation will be decreasing.
Generally speaking, the highest power generation efficiency of the system is achieved in the northern hemisphere with a due south orientation and the best angle of inclination. However, in practice, especially in distributed photovoltaic, by the building layout conditions and scene area restrictions, photovoltaic modules often can not be installed in the best orientation and the best tilt angle, component multi-orientation has become one of the distributed roof photovoltaic system power generation pain points, so how to avoid the loss of power generation brought about by multi-orientation, has become another problem in the development of the industry.
2. The “short board effect” in multi-directional roofs
In the traditional string inverter system, the modules are connected in series, and their power generation efficiency is restricted by the “short board effect.” When a string of modules is distributed in multiple roof orientations, the reduced power generation efficiency of one of the modules will affect the power generation of the whole string of modules, thus affecting the power generation efficiency of multiple roof orientations.
Micro inverter adopts full parallel circuit design, with independent maximum power point tracking (MPPT) function, which can completely eliminate the “short board effect” and ensure that each module operates independently and the power generation does not affect each other, compared with traditional string inverter system, under the same conditions, it can generate 5%~25% more power and improve investment income.
Even if the modules are installed on roofs with different orientations, the output of each module can be optimized near the maximum power point, so that more roofs can be “clothed in PV” and generate more value.
3. Micro-inverter in multi-directional roof application
Micro inverters, with their unique technical advantages, are extremely suitable for multi-directional rooftop PV applications, and have served more than 100 countries and regions, providing MLPE module-level technical solutions for multi-directional rooftop PV.
4. Household PV Project
Recently, a 22.62kW system capacity PV project was built in Brazil. At the beginning of the project design, the owner expected After the project design, the PV modules were finally installed on seven roofs of different orientations, and with the use of micro-inverter products, the roofs were fully utilized. In the actual operation of the power plant, affected by multiple orientations, the amount of solar radiation received by the modules on different roofs varies, and their power generation capacity varies greatly. Take the circled modules in the figure below as an example, the two facing roofs circled in red and blue correspond to the west and east sides respectively.
5. Commercial PV projects
In addition to residential projects, micro inverters are also being used in commercial and industrial applications while facing the roof. Last year, a commercial and industrial PV project was installed on the roof of a supermarket in Goits, Brazil, with an installed capacity of 48.6 kW. At the beginning of the project design and selection, the location is circled in the figure below. Based on this situation, the project selected all micro-inverter products, so that the power generation of each roof module does not affect each other, to ensure the power generation efficiency of the system.
Multiple orientations have become another significant feature of distributed rooftop PV today, and micro inverters with component-level MPPT function are undoubtedly a more suitable choice to cope with the power loss caused by different orientations. Gather the light of the sun to illuminate every corner of the world.