The paper investigates the supply structure of the capacity market in Poland in the coming years. The results of the capacity auctions conducted in 2018 are analyzed for this purpose. Three auctions were held at that time. The products traded in the capacity market are capacity obligations for the following years: 2021, 2022 and 2023. The auctions were organized in accordance with (i) he Act of December 8, 2017 on the Capacity Market and the (ii) Capacity Market Regulations published by the Polish Power Grid. The source of data used in this study is the official information of the President of the Energy Regulatory Office on the final results of the main auctions for 2021–2023 delivery periods. The list of the capacity suppliers who won capacity auctions contains the type of capacity market units, the volume of capacity obligations, the duration of capacity agreements and the business name of the capacity suppliers. The conducted analysis indicates that the auction for 2021 was won mainly by existing units (45.81%) and refurbishing units (33.51%). In subsequent years, the share of existing generating units is significantly higher and amounts to 91.67% for 2022 and 84.54% for 2023. The results of the study carried out in this paper also show that one energy company, being the owner of power generating daughter companies, has a very high share in these capacity auctions. The PGE Capital Group contracted 51.95% for 2021, 69.92% for 2022 and 64.44% for 2023 of the total capacity obligation. The volume amounts to over 70% of their total installed capacity.
With the upcoming implementation of the centralized capacity market in Poland, capacity auctions will be organized where domestic power companies will offer their available capacities. It is assumed that bidding will be auctioned according to the so called descending clock auction system with uniform-price (Pay-as-Clear), which will lead to the market equilibrium price. Some analysts, however, are of the view that it is more appropriate to organize capacity auctions in the Pay-as-Bid formula, as this system should lead to lower prices that those of Pay-as-Clear, hence lower costs of capacity purchase. However, this opinion does not confirm the practice – theoretical considerations do not take into account such important factors as the behavior of market players and the tendency of bidders to accept a higher risk or the lack of access to advanced analyses, and thus better information for all market participants. This paper presents a hypothetical calculation of the prices in the centralized capacity market using Monte Carlo simulations. The results of the study confirm that the price level for the Pay-as-Bid system, due to the asymmetry of information and the level of concentration of the power generation sector in Poland would lead to higher prices than for the Pay-as-Clear system on average by approximately 2.5%. The implementation of the PAB system would, therefore, be less efficient to electricity consumers.