Sustainable energy transition is a vital component of global climate policy and economic development. However, many countries, especially in the developing world, face significant challenges in allocating sufficient public funds for renewable energy projects. This paper investigates the key limiting factors affecting budgetary allocation for sustainable energy, including fiscal constraints, short-term planning horizons, debt obligations, and institutional inefficiencies. Using a mixed-methods approach and a case study of Uzbekistan, the study identifies how these factors restrict the effectiveness of national energy strategies. The paper proposes policy recommendations such as multi-year budgeting, green fiscal reforms, and improved institutional coordination to enhance the efficiency of public investment in renewable energy. The findings aim to support more strategic and impactful budgetary planning for energy transitions in resource-constrained settings.