Abstract
The undergoing energy transition relies heavily on the deployment of renewables such as solar photovoltaic (PV) and wind power for the generation of electricity. These variable and intermittent resources would modify power systems’ reliability compared to the situation where electricity is generated by conventional dispatchable power plants. It is also important to accurately capture their contribution to resource adequacy in long-term expansion planning. This discussion paper assesses how varying the firm capacity (FC) and forced outage rate (FOR) assumptions of renewable energy (RE) impact capacity expansion models (CEM). Eight scenarios that vary the FC and FOR, RE share targets, and annual RE uptake were run on a power system model of Saudi Arabia. Assuming a relatively high FC and a relatively low FOR favors renewables (i.e., Optimistic-RE), while the opposite disfavors them (i.e., Pessimistic-RE). Compared with optimistic RE assumptions, the pessimistic RE assumptions result in significant increases in costs, emissions, and battery storage deployment of up to 11%, 17%, and 41%, respectively. However, no observable patterns were found for resource adequacy. Quantifying the extent to which FC and FOR of RE technologies, which are considered heavily weather-dependent, impact investments in the power sector provides valuable insights for policymakers as the world moves forward more aggressively with RE deployment to reduce emissions and combat climate change.
