Backup solar PV plant «Sunflower-90» was built in 2014 in the Kirovograd region. The total capacity of PV modules installed on the mobile tracker biaxial structures is 90 kWp. This facility is designed to produce clean electricity, followed by its use for own needs of the agricultural farm. In the future, provided the opportunity to accumulate surpluses generated electricity in batteries.
The power plant is designed with the use of three-phase string inverters manufactured by Danfoss/SMA power of 15 kW, and multicrystalline silicon modules LDK with a peak power of 250 watts. One inverter serves three tracker, each of which is set to 5 kW of solar panels. The station is controlled by its own monitoring system, which allows to analyze its status from anywhere in the world and get to know the amount of energy generated by the power plant in a given period of time.
In this project, the company Rentechno acted as general contractor, namely completed development of project design documentation, provided all the necessary equipment and accessories, and also undertook the construction of solar power plants «turnkey», which was completed with commissioning works.
Sunflower – 90 solar power-station includes automatic monitoring and management system that functionally divides into following subsystems:
In order to practically implement specified operational algorithms of the station, Rentechno specialists developed special software environment. Its main feature is possibility of correct reaction of both software and hardware parts of solar power-station on various force-majeure and non-standard circumstances of any kind, including interferences, caused by human factor. In case of breakdown double backup is provided for all most critical and important blocks of the station.
As far as equipment, working in a farm, usually includes many electric motors (from ventilator drives with little power, to powerful 35 kW engines, used in grain dryers), so the project design included the special possibility to compensate inductive reactive-power, which is consumed by electric motors. This realized solution allowed to considerably decrease electricity bills of the enterprise.
The main feature of this project is abandonment of stationary supporting metalworks in favor of dynamic biaxial trackers. Calculations show that use of dynamic trackers will allow to increase electricity generation amounts about 30-35% annually.
Analysing data from several luminosity sensors, control system automatically corrects position of tracker to achieve the maximally possible amount of solar energy at this time. Experience and statistical observations show that direct orientation on the Sun and direction, providing maximal luminosity level, do not coincide quite often. Such situation was observed during model field tests in the place, where the station was further installed. For this solar station the necessity of installation of active control system was to a large extent determined by the fact, that few solid metal elevator jars 27 meters high are located nearby. Under certain conditions and location of the Sun these jars play the role of unfocused mirrors, which create dissipated and reflected solar radiation; power of the latter can excel direct solar radiation.
Installation of dynamic system, which corrects position of solar trackers, has another advantage: it allows to avoid damage of solar panels (they have quite large area) under high wind. Due to permanent data tracking on current weather situation the system checks wind strength and if it overcomes some specified threshold, then solar batteries are automatically transferred in the most safe position, named feathering position.
In 2016 Sunflower-90 solar station was redesigned for generating and sale of electric power into general network on green tariff rates.