Continued sharp rise in strain on Verbund power grid


The climatic conditions in the winter half-year 2008/09 led to reduced energy production in the VERBUND-Austrian Power Grid AG control area, which, in turn, led to an increase in electricity imports.

With there also being an increase in power production from alternative energy sources, the demands placed upon the extra-high voltage grid of VERBUND-Austrian Power Grid AG were clearly high. Fact is: Additional investments are urgently needed, if Austria’s supply security is to be ensured in the future!

VERBUND-Austrian Power Grid AG is upbeat about its performance in the past winter half-year: Despite constantly increasing short-term load fluctuations in the grid run by control area manager VERBUND-Austrian Power Grid AG, supply security could be maintained throughout the winter semester.
A comparison of the data of the past winter half-year with the current trends in electricity imports/exports makes it particularly clear how high the demands are, which the 380 kV extra-high voltage grid is exposed to - demands which fluctuate widely within the course of a year.

In winter 08/09 electricity consumption totalled 25.2 TWh in the control area of VERBUND-Austrian Power Grid AG, which is down 3.2 % from last winter. Equally, a clear decline can be seen in the total amount of energy produced in this area: Compared to last year, records show a drop of 7.2 % to 23.6 terawatt hours (TWh) - a trend that was mainly caused by a low production coefficient in the domestic run-of-river power plants.

But even during this period, the 5.1-% rise in energy production from alternative sources (wind, biomass and so forth) required the repeated use of installed bottleneck management measures. Thanks to this balancing system based on especially erected transformers, VERBUND-Austrian Power Grid AG was able to ensure uninterrupted service at all times, even at maximum grid load. Nevertheless, grid security is showing a tendency to worsen over time.

Import increase in winter half-year
The latest figures in the electricity import and export balance sheet reveal the actual extent of the rise in fluctuations, the domestic grid is exposed to:  Unlike the rising imports in the winter half-year, this April saw the balance of exports over imports soar, reaching new record levels of 654 gigawatt hours (GWh) (imports: 469 GWh, exports: 1,123 GWh) due to the snowmelt starting in late March. In May another export record followed (on balance) of 917 GWh (imports: 176 GWh, exports 1,093 GWh). By comparison, the annual electricity produced at Freudenau power plant is 1,052 GWh.

Nevertheless, full-year forecasts indicate an excess of imports over exports in the control area of VERBUND-Austrian Power Grid AG for the current year.
Fact is: Due to the forecasted expansion of renewable energy sources, particularly wind power, and a large number of planned new power plants in Austria, the widely fluctuating and therefore increasingly unpredictable load flows will continue to rise. Against this background, the costly bottleneck management systems in place are rapidly approaching their limits.

Investments urgently required
Investments are therefore urgently needed, if grid reliability in the control area of VERBUND-Austrian Power Grid AG is to be ensured in the future. For this reason, Austria’s largest power grid operator stresses the urgency of a rapid realization of the 380 kV security ring for Austria. With the planned commissioning of the Styria line in mid-2009, the first step in the right direction is taken. Apart from that, a rapid approval of further projects should ensure that domestic supply security is not increasingly jeopardized any further.

Outlook: Summer half-year 2008/2009
The forecasts assume that the summer will be warm and dry with low consumption increase.
The commissioning of the 380 kV Styria line will ease the grid situation at the connections to Styria and Carinthia. But due to the still insufficient north-south connections in the west of Austria, the overall situation will remain tense.