Optimal design of feed-in-tariffs to stimulate renewable energy investments under regulatory uncertainty - A real options analysis

- We assess the impact of feed-in-tariffs on investment in renewable energy sources.
- We investigate this impact both with and without regulatory uncertainty.
- This effect is quantified using a real options model with regime switching.
- Renewable investments become now-or-never decisions under fixed feed-in-tariffs.
- Regulatory uncertainty distorts the impact of feed-in-tariffs on investment.

Feed-in-tariffs (FITs) are widely used as policy instruments to promote investments in renewable energy sources (RES). While FITs are often regarded as the most effective RES support scheme, regulators around the world continuously review their FIT schemes in the light of budget constraints and evolving policy goals. We assess the impact of adjustments to FIT schemes by quantifying the relationship between FIT levels, i.e., the guaranteed amount paid per quantity of electricity produced and the propensity to invest in RES. Through a regime switching model, we quantify the impact of regulatory uncertainty induced by regulators considering moves from a FIT scheme to a more market-oriented regulatory regime. Our focus is on market-independent, fixed FITs, the dominant scheme in Europe receiving increasing attention globally. We find that RES investment projects under market-independent, fixed FIT schemes become now-or-never decisions and derive FIT thresholds required to induce investment. We show that uncertainty regarding future regulatory regimes delays or even reduces investment activity for FIT levels near electricity market prices and high probabilities of an imminent regime switch.