• Energy Research

To meet the nationally determined contributions proposed by the countries that signed the Paris Agreement, investments must be made in renewable generation technologies such as solar and wind. However, due to their high variability, these technologies pose challenges in terms of meeting demand or generating excess electricity. For this reason, energy system models are designed to capture this variability by considering flexibility technologies. Nevertheless, it is important to note that some energy system models lack integration with other sectors. Therefore, integrated assessment models have been employed to evaluate mitigation strategies, as they endogenously consider the linkages between energy and non-energy sectors. In addition, due to their complexity, these models do not account for the variability of renewable resources. Hence, this research aims to address this issue. This work represents the first attempt to evaluate how the introduction of hourly resolution affects the outcomes of integrated assessment models, specifically focusing on the Global Change Analysis Model (GCAM). We employ a soft-linking approach between the GCAM and the Highway to Renewable Energy Systems model (H2RES, an hourly level energy system model) to accomplish this. The proposed approach is tested using Chile’s Nationally Determined Contributions under different hydrological profiles in the power sector. The results show that it is possible to use the capacity obtained from the Global Change Analysis Model and implement it on an hourly scale. However, the feasibility of implementation depends on high levels of flexibility technologies, such as battery energy storage. When given the choice of investments in renewable sources and flexible technologies, the optimal dispatch of the H2RES model show small differences than those obtained by GCAM-Chile. H2RES differs from GCAM-Chile in approximately 5% for wind and 3% for solar electricity generation in the year 2050. However, feasible integration of significant renewable sources is obtained with relatively high Critical Excess Electricity Production levels, reaching 20% in 2050. This excess electricity is attributed to the necessity for flexible technologies to manage the intermittency of renewables sources when hourly profiles of such sources are considered.

Given the possible economic consequences, poorer countries have more challenges in delivering their Nationally Determined Contributions. As a developing country, Chile has pledged to attain carbon neutrality by 2050. While Chile has implemented several mitigation measures, it still relies heavily on carbon sequestration, intending to sequester around 65 MtCOe by 2050. However, heavy reliance on sequestration poses several risks as the literature shows that natural sinks, particularly forest and land, are exposed to severe impacts from global warming and climate change. Fortunately, Chile has significant renewable energy potential, which, if fully utilized, may move the country towards a net negative emissions context. To assess if such a net-negative system is feasible in the context of Chile, a new regional version of the Global Change Analysis Model for Chile is developed. The model is used to investigate the effects and required levels of investment in renewable energy and decarbonization of end-use sectors to achieve economy-wide net negative emissions scenarios. The design of net negative pathways follows a statistical approach based on the expected sequestration capacity in 2050 and its corresponding confidence interval. The results are compared to scenarios that are aligned with the objective of carbon neutrality by 2050. The findings show that obtaining net-zero emissions by 2050 is possible, however achieving net negative systems will be dependent on existing sequestration capacity and the application of economic incentives to boost green energy deployment in Chile as well as to push such green energy, in the form of electricity or e-fuels, into hard to decarbonize final demand sectors, such as transport, mining, and industry demand sectors. The results also indicate that after significantly reducing CO emissions from the energy sector (primarily the power sector), the agricultural sector and other urban and industrial sectors still contribute to non-significant levels of CH and NO emissions.