The value of investments in renewable resources of electrical energy, mainly in using wind and solar energy has increased greatly in the last 15 years. It has been mainly a result of political decisions, which were inclined to the idea of using renewable resources. Through the programs the European Union has committed itself to, it strives to the highest possible share of renewable resources. The most current one is a Europe 2020 Strategy, which predicts a 20% decrease in CO2 emissions in comparison to the year 1990, a 20% share of renewable sources in primary energy consumption and a 10% increase in energy efficiency. For accomplishing these goals, a lot of investments in new technologies and renewable resources are needed. Financial incentives or subsidies, offered by EU countries, play an important role in investing in solar and wind power plants.
Austria is one of the leading EU countries in the share of renewable resources for electrical energy production. The majority share is represented by using water resources. In the recent years the country increased investments in solar and especially wind power plants. The installed capacity of wind power plants in Austria represents a significant share of total installed capacity of the country. Austria’s main feature is that the areas where the wind conditions are appropriate for power plants are condensed in the eastern and north-eastern parts of the country. The power plants are therefore placed on a relatively small area, which results in a very inconsistent production of energy from wind power plants in case of changeable wind conditions. This can lead to an imbalance in the system, meaning that the production does not follow the consumption. When such imbalance in the system occurs, the system operator has to balance the system. If the imbalance lasts for a longer period of time, then the tertiary control or minute reserve has to be activated. Tertiary control thus relieves the primary and secondary control for the case of repeated instability in the system.
Between the years 2010 and 2015 Austrian costs intended for tertiary control activations increased annually. This rise is due to an annual increase of average price of activation and an increase in number of tertiary control activations. At the same time the installed capacity of wind power plants more than doubled, from 1011 MW to 2306 MW of installed capacity. When comparing the data of predicted and actual production of electrical energy from wind power plants, I found out that in some cases of tertiary control activations there has been a significant deviation between the prediction and actual production from wind power plants. Thus, I reached the conclusion that the inconsistency of production from wind power plants affects Austria to the extent that tertiary control activations are needed for balancing the electrical power grid.