Renewable Energy Sources vs Control of Slovak Electric Power System [chapter]

Juraj Altus, Michal Pokorny, Peter Bracinik
2011 Renewable Energy - Trends and Applications  
Introduction The chapter presents issues of renewable energy sources connection into Slovak power system. It describes calculation techniques for estimating acceptable RES capacities, which can be connected into the system, without jeopardizing security and quality of supplied electricity. Calculations of additional expenses for regulation power purchase for various values of RES capacities connected are presented in the second part of the chapter. The interest in construction of photovoltaic
more » ... n of photovoltaic power plants in Slovak Republic soared in 2008. A new act concerning renewable energy sources and remarkably generous prices paid for electricity from these sources (associated with the act) stimulated investors' interest in building new plants. Based upon experience from other countries and following analysis of possibilities for procuring own sources of balancing electricity for auxiliary services, Slovak E l e c t r i c i t y T r a n s m i s s i o n S y s t e m , P l c . ( S E P S ) p l a c e d a n o r d e r t o D e p a r t m e n t o f P o w e r Electrical Systems to elaborate a study in which a maximum capacity of PV plants would be determined, which can be connected into the power system, taking into account availability of balancing power for secondary and tertiary regulation. Developed study determined 120 MWp as maximum power of PV plants, which can be connected in 2010. Influence from EU side and from investors and construction of new thermal and nuclear power plants in Slovakia necessitated an elaboration of a new study, which would analyse the situation in transmission system with respect of balancing electricity for the case, when new PV plants with capacity up to 1 200 MWp are connected. This chapter presents solution of this matter and some results. Determination of connectable capacity of PV plants into power system of Slovakia can be accomplished from different points of view. One of them can be based on the basic condition, which is used in all studies concerned PV plants connection into distribution network. This condition states, that voltage change in point of common coupling should be less than 2 %, compared with the situation before plant connection. If this condition is applied, resultant connectable capacity should be relatively high, as 22 kV lines can easily withstand considerably higher loads than those of current ones. Probably 80 to 90 % of demanded capacity could be accepted in this case. This consideration can be hardly accepted due to sources features, which show a vast variability of power, practically in whole power range. In addition, capacities of PV plants are usually lower than 4 MW, thus the responsibility for balance is brought to the distribution company. But the power balance can only be solved on the Slovak transmission system level. www.intechopen.com Renewable Energy -Trends and Applications
doi:10.5772/26772 fatcat:sukn5emx35h2voclnxb2priazu