Eberstalzell in scenic Upper Austria not only boasts the largest photovoltaic (PV) research power station in Austria, it is also the site of a Smart Grid demonstration system. The aim of the system is to be well prepared for the increase in use of renewable sources of energy. Stable grid operation and maximum reliability of supply must be guaranteed. Fronius inverters support these objectives.
Schematic of DG DemoNet Smart LV Grid project; Copyright: Energie AG Upper Austria, reproduction free of charge.
By the end of 2015, it is expected that 6,000 new solar power systems will go on stream in Austria each year. The grids must be able to cope with this onslaught, so robust and intelligent systems are the order of the day. The pilot project in Eberstalzell is a control concept for an active low-voltage grid. A specific grid segment that will contain around 70 photovoltaic systems is to be used as a test array. A Fronius IG Plus V inverter will be installed in each of these PV systems to provide stable grid operation.
"This test grid will enable us to control the devices within it. Existing control functions in the inverter can be modified and optimised from a higher-level grid controller, transforming a low-voltage system into a Smart Grid."
explains Dr. Martin Heidl of Fronius System Technology. The objective is to be able to feed in more decentrally generated electricity, without any power losses, than would be possible were the Smart Grid measures not in place.
The reactive power control provided by the Fronius inverter enables the grid voltage to be held within the required limits. Being able to communicate directly with the Smart Grid means that the technically ingenious control algorithms in the Fronius inverter can be modified remotely. The Smart Grid Controller uses data from the Smart Meter to control the transformer and the inverter, enabling the entire grid to be optimised in terms of voltage stability, maximum feed-in and low levels of loss.
The research project is being led by the AIT (Austrian Institute of Technology) and carried out in conjunction with Energie AG Oberösterreich Netz GmbH, Siemens AG Austria, Linz Strom Netz GmbH, Salzburg Netz GmbH and BEWAG Netz GmbH. Installation will start in spring 2012 and the project as a whole is scheduled to run for three years.
The PV research power station in Eberstalzell is the source of another item of good news. Here, 18 Fronius CL central inverters have been providing unusually rosy results for one year now: *current yields are ten percent higher than the already optimistic forecasts provided by the solar specialists. On April 16th, the 1,000,000th kilowatt hour of electricity was fed into the Energie AG grid.
* Source: Press release from EnergieAG Oberösterreich, 06.05.2011.