The impact of uncoordinated development of photovoltaic power plants on electricity market in Czech Republic

摘要

During a few recent years, Czech Republic experienced a steep increase in the generation of electricityfrom renewable energy sources (RES). Due to interplay of several factors, a marked uncoordinatedincrease of the share of a single RES type – namely PV electricity – occurred within a very short timeperiod. By the end of 2010, the total installed capacity of photovoltaic power plants (PVPPs) in theCzech power system amounted to nearly 2000 MW, the peak load being around 11 000 MW and theminimum load around 4500 MW. Just these basic data show that the installation of such a huge photovoltaic(PV) generating capacity has a serious impact not only on the operation of the power systemitself, but also on trading with electricity (spot market, imbalances, ancillary services, etc.), and, due tothe support scheme established, on prices for final customers.The basic form of the support for generation of electricity from RES in the Czech Republic is fixingthe minimum purchase prices by the regulator. Moreover, the Act 180/2005 Coll. on Support forElectricity Generation from RES contained a provision according to which the minimum purchaseprices for electricity generated from RES may not be decreased annually by more than 5 %, whichshould have provided an appropriate price signal for investments into RES. The minimum purchaseprice for electricity generated in PVPPs was set, according to the Act above, to a relatively high levelcompared with the wholesale market prices of electricity so as to meet the legal guarantee of 15-yearsreturn on investments for investors. However, investment requirements of PVPPs kept decreasing inthe past five years markedly and, hence, investments into this source type turned out to be veryattractive. The paper explains both the direct impact on electricity prices in the components subjectedto regulation and the indirect impact on ancillary services and their prices. The paper further specifiesthe necessary measures that were taken as a response to the PVPP boom on legislative level as well asin the rules for the operation of distribution grids (Grid Code). The papers discusses, from the point ofview of the operator of the Czech national transmission network, the ČEPS company (Czech TSO),problems brought about by this massive growth (purchase and activation of ancillary services, impactson ancillary services market, analysis of the impact of the increased PV power generation on thesystem imbalance, impacts on intraday energy market or on balancing market with balancing energy.The paper concludes with the presentation of further anticipated measures, primarily the change of themechanism of RES support, based on a deeper linkage to the wholesale spot market and the transfer offinancial burden of regulated (private) subjects on a state subject. A list of measures also includes theNational Action Plan (NAP), which should guarantee a more coordinated development of RES in thetime horizon up to 2020.