Trade-offs in feed-in tariff scenarios for incentivizing clean technologies in Central and Eastern Europe

• A new model for residential technology adoption in the CEE region is proposed. • Different feed-in tariff scenarios are analysed across eight countries. • The trade-offs between rooftop PV and battery storage adoption are examined. • Moderately low feed-in tariffs offer the greatest benefit to the grid. • Peak pricing schemes are crucial for maximizing the use of residential batteries. The rapid expansion of rooftop photovoltaic systems in Central and Eastern Europe is transforming residential electricity markets, necessitating a re-evaluation of feed-in tariff policies. Feed-in tariffs play a critical role in shaping the adoption of both rooftop solar panels and residential battery storage. However, their interaction remains insufficiently explored. This study employs the Clean Energy Adoption in the Residential Sector, CLEARS, model to simulate the diffusion of rooftop solar energy and battery storage under various feed-in tariff scenarios across eight countries in Central and Eastern Europe. The findings highlight a trade-off: while high feed-in tariffs accelerate the adoption of rooftop solar panels, they discourage battery storage, potentially destabilizing the electricity grid. Conversely, lower feed-in tariffs encourage battery uptake but may slow the expansion of rooftop solar energy. A moderately low range of feed-in tariffs is identified as optimal for balancing these dynamics, though it varies across countries. Furthermore, a peak-pricing feed-in tariff strategy—offering higher compensation for electricity sold during periods of high demand—enhances the financial attractiveness of battery storage and strengthens grid resilience. These results underscore the need for well-calibrated feed-in tariff policies to optimize self-consumption, support grid stability, and facilitate a sustainable energy transition in Central and Eastern Europe.