The aim of the artice. Taking into account the urgent need of rebuilding the national economy and energy system after the war destruction on the principles of green energy transition, it is extremely important to develop the startup movement in the field of alternative & renewable energy. The active implementation of the principles of an innovation-oriented circular economy requires significant and well-thought-out reforms in both economic relations and technology advancement. In this context, it is important to actively implement the concept of sustainable development, ensure the promotion of environmentally friendly goods and services on the market, and minimize the consumption of traditional fossil fuels, as well as the use of agricultural land for growing fuel crops. Thus, the purpose of the study is to analyze the innovativeness of business processes of national startups in the field of green alternative energy and to substantiate the peculiarities of business planning of environmentally friendly startup projects in the context of the green energy transition (also associated with the concepts of the renewable energy transition and the green deal). Analysis results. The paper explores business processes in the field of green startups, describes in detail the author's Bioenergy-Startup project, and substantiates its Business Model Canvas. The Bioenergy-Startup project has a positive environmental and economic effect and makes it possible to significantly reduce toxicant emissions from vehicle engines and diesel-fueled boiler plants. The project is also aimed at greening the country's economy by reducing the technogenic load on agricultural land through the use of fat-containing production waste, promoting the rational use of natural resources, and reducing greenhouse gas emissions, as well as the emissions of so-called black carbon. Using the Bioenergy-Startup project as an example, the authors proposed a framework for implementing a startup, starting from the creation of the Business Model Canvas and taking into account the levels of technological innovation and risks. In creating this framework, the authors took into account, in particular, the Customer Development and Lean Startup methodologies, the work of domestic scientists, as well as their own experience in the field of innovative entrepreneurship. During the implementation of the Bioenergy-Startup project, one of the main tasks from the marketing point of view was to create and communicate to the target audience significant competitive environmentally friendly advantages that are not only consistent with the concept of sustainable development and a green (circular) economy but also provide an opportunity to save valuable natural resources, promote the decarbonization of industry and transport, prevent climate change on the planet, etc. Conclusions and directions for further research. To accomplish this task, the authors have developed a marketing strategy for promoting the innovative products of the Bioenergy-Startup, as well as a specific algorithm for promoting the startup's innovative products, a schematic representation of which is given in the paper.