An Influence of Group Purchasing Organizations on Financial Security of SMEs Operating in the Renewable Energy Sector—Case for Poland

European countries are increasingly using renewable energy. Poland is an outsider of such solutions. The Polish energy sector is primarily based on energy produced from coal. However, environmental changes and regulations of the European Union are forcing the increased use of energy from renewable sources. Renewable energy is an industry that is still developing in Poland. At the same time, Poland is a country where the political decisions of the government over the last few years have resulted in a significant limitation of the possibilities of renewable energy development. These actions have also resulted in lowering the profitability of the currently operating renewable energy enterprises, especially those from the sector of small and medium-sized enterprises. An opportunity for SMEs operating in the renewable energy sector is to merge into industry purchasing groups. The aim of the article—and at the same time the research question—is: Is it financially safer for renewable energy companies to operate within purchasing groups compared to companies operating independently in this industry? Traditional ways of purchasing can be transferred to integrated purchasing systems, which will be created by purchasing groups associating renewable energy companies. For this purpose, the financial effects of the implementation and functioning of the purchasing groups in the renewable energy sector in relation to entities operating independently were examined. In the research of renewable energy SMEs, a comparative analysis of key indicators determining the possibility of continuing the activity of these entities was made. The following indicators were examined: current financial liquidity ratio, return on sales, operating cycle, cash conversion cycle, share of receivables in current assets, share of inventory in current assets, turnover ratios, level of receivables, liabilities and profitability. The scientific literature is dominated by studies on purchasing groups in the pharmaceutical and construction industries. Thanks to the research conducted, it has been indicated that the renewable energy industry can also improve its profitability, and thus the possibility of safe continuation of operations by extending the business model to inter-entity cooperation within purchasing groups. Increasing the efficiency of individual entities of the renewable energy industry within purchasing groups becomes particularly important during the COVID-19 pandemic. Statistical analyses and their graphic presentation present the significant impact on the safety and profitability of renewable energy entities in the form of purchasing groups.