What are the real implications for $CO_2$ as generation from renewables increases?

TL;DR

This paper examines how increasing renewable energy sources like wind and solar impact the operation of thermal power plants and overall emissions, revealing complex system responses beyond simple displacement.

Contribution

It introduces a method for tracking the effects of renewable capacity growth on thermal plant operations and emissions in low-carbon electricity systems.

Findings

Renewables displace conventional generation but alter thermal plant operations.

Displacement of generation is not a 1-to-1 ratio as expected.

The method helps policymakers monitor system-level impacts of renewables.

Abstract

Wind and solar electricity generation account for 14% of total electricity generation in the United States and are expected to continue to grow in the next decades. In low carbon systems, generation from renewable energy sources displaces conventional fossil fuel power plants resulting in lower system-level emissions and emissions intensity. However, we find that intermittent generation from renewables changes the way conventional thermal power plants operate, and that the displacement of generation is not 1 to 1 as expected. Our work provides a method that allows policy and decision makers to continue to track the effect of additional renewable capacity and the resulting thermal power plant operational responses.