US Renewable Futures in the GCAM

Abstract

This project examines renewable energy deployment in the United States using a version of the Global Change Assessment Model (GCAM) with a detailed representation of renewables, the GCAM-RE. Electricity generation was modeled in four generation segments and 12-subregions. This level of regional and sector detail allows a more explicit representation of renewable energy generation. Wind, solar thermal power, and central solar PV plants are implemented in explicit resource classes with new intermittency parameterizations appropriate for each technology. A scenario analysis examines a range of assumptions for technology characteristics, climate policy, and long distance transmission. We find that renewable generation levels grow over the century in all scenarios. As expected, renewable generation increases with lower renewable technology costs, more stringent climate policy, and if alternative low-carbon technologies are not available. The availability of long distance transmission lowers policy costs and changes the renewable generation mix.iv

Endogenous Assessment of the Capacity Value of Solar PV in Generation Investment Planning Studies

“…Other models account for the variation in the capacity value of solar indirectly by, for instance, a requirement of backup conventional generation that changes with penetration levels [58]. However, the capacity value of solar in all of these models and studies is exogenously defined, which could over or underestimate the need for firm capacity to meet resource adequacy targets.…”

Advanced Methods for Incorporating Solar Energy Technologies into Electric Sector Capacity-Expansion Models: Literature Review and Analysis

“…One common formulation is a requirement that VRRE be accompanied by backup capacity to fill the gap between the VRRE's capacity value and its nameplate capacity. These formulations, as with GCAM (Smith et al 2011), allow erosion of capacity value with increasing VRRE penetration: a low level of required backup with little solar increases to higher levels-even 100% backup-at high solar penetration. There is risk in such a backup-capacity formulation of over-penalizing the renewable generator by requiring backup capacity even if the system already meets resource adequacy.…”