NEA (Nepali Electricity Authority) is the Nepali government owned electricity authority, responsible for the nation’s electricity generation and distribution through the grid.
NEA’s Min Bhawan building in Kathmandu does not experience any load shedding, thus has 24/7 access to the grid. This is the “ideal” for a solar PV grid connected system as that enables to feed all the daily generated solar PV array energy into the grid. Therefore the Solar PV Grid Connected System type for the NEA Plant 2 is a “normal” grid connected solar PV system, with a solar PV array and a grid connected inverter. This type of grid connected solar PV system is well known in other countries, such as Germany, where they have become a common site and are a part of the national energy generation infrastructure.
In order to understand the difference in performance of grid connected inverters, there are three, equal sized, grid connected 1.11 kW rated solar PV arrays installed, each with a different grid inverter of similar rated power generation capacity of around 1.2 kW. One system has an SMA Sunny Boy, from the leading grid inverter manufacturer SMA from Germany. The second system has a Fronius grid inverter, from the well experienced and internationally well-known company Fronius in Austria. The third system is a Solar River grid inverter from the company Samil Power in China. In this way we can directly compare the performance of the three different grid inverters under every possible condition throughout the year and find out which performs the best in regard to maximum grid fed energy and least down time for the meteorological conditions experienced in Kathmandu.
The three NEA Plant 2 solar PV systems were connected to the grid on the 20th December 2012, in the presence, and with the authority of NEA delegates.
You can download the Plant 2 Block Diagram here.