A Significant Role for Renewables in a Low-Carbon Energy Economy?

Abstract:

Renewables currently make up a small (but growing) fraction of total U.S. electricity generation. In some regions, renewable growth has resulted in instantaneous penetration levels of wind and solar in excess of 60% of demand. With decreasing costs, abundant resource potential and low carbon emissions and water requirements, wind and solar are increasingly becoming attractive new generation options. However, factors such as resource variability and geographic distribution of prime resources raise questions regarding the extent to which our power system can rely on variable generation resources. Here, we describe scenario analyses designed to tackle engineering and economic challenges associated with variable generation, along with insights derived from research results. These analyses demonstrate the operability of high renewable systems and quantify some of the engineering challenges (and solutions) associated with maintaining reliability. Key questions addressed include the operational and economic impacts of increasing levels of variable generation on the U.S. power system. Since reliability and economic efficiency are measured across a variety of time frames, and with a variety of metrics, a suite of tools addressing different system impacts are used to understand how new resources affect incumbent resources and operational practices. We summarize a range of modeled scenarios, focusing on ones with 80% RE in the United States and >30% variable wind and solar in the East and the West. We also summarize the environmental impacts and benefits estimated for these and similar scenarios. Results provide key insights to inform the technical, operational and regulatory evolution of the U.S. power system. This work is extended internationally through the 21^st Century Power Partnership’s collaborations on power system transformation, with active collaboration in Canada, Mexico, India, China and South Africa, among others.