Adverse effects of rising interest rates on sustainable energy transitions

Increasing the use of renewable energy (RE) is a key enabler of sustainable energy transitions. While the costs of RE have substantially declined in the past, here we show that rising interest rates (IRs) can reverse the trend of decreasing RE costs, particularly in Europe with its historically low IRs. In Germany, IRs recovering to pre-financial crisis levels in 5 years could add 11% and 25% to the levelized cost of electricity for solar photovoltaics and onshore wind, respectively, with financing costs accounting for about one-third of total levelized cost of electricity. As fossil-fuel-based electricity costs are much less and potentially even negatively affected by rising IRs, the viability of RE investments would be markedly deteriorated. On the basis of these findings, we argue that rising IRs could jeopardize the sustainable energy transition and we propose a self-adjusting thermostatic policy strategy to safeguard against rising IRs. Renewable energy costs have declined in the past but things could change with increasing interest rates. This study shows that in Germany, if interest rates increased to pre-financial crisis levels in 5 years, the levelized cost of solar photovoltaics and onshore wind could rise by 11 and 25%, respectively.