This research presents a pioneering, hourly-resolved energy system modeling study for achieving a 100% renewable energy (RE) supply across South and Central America by the year 2030. The study addresses the region's dual challenge of sustaining economic growth while transitioning its already high-renewable share (dominated by hydropower) towards a more diversified, resilient, and fully sustainable system. The core innovation lies in integrating not just electricity but also water desalination and synthetic natural gas (SNG) production via power-to-gas (PtG) into a single optimized model.
2030
Hourly
15
4
The study employs a linear optimization model to minimize the total annual cost of the integrated energy system, subject to meeting hourly demand for electricity, water, and gas.
The model is a cost-optimization tool that determines the optimal mix of generation, storage, and transmission capacities. It uses historical weather data (2005-2009) for solar irradiance and wind speeds to generate synthetic hourly capacity factors for PV and wind power plants across the 15 sub-regions.
The continent was divided into 15 sub-regions based on political borders and energy market structures to accurately model resource distribution and transmission needs.
The model finds that a 100% RE system is technically feasible. The installed capacity is dominated by solar PV (approx. 415 GW) and wind power (approx. 200 GW), with existing hydropower (approx. 150 GW) providing balancing and storage. Biomass and geothermal play minor, complementary roles.
A critical finding is the use of existing hydro dams as "virtual batteries." By strategically dispatching hydropower in conjunction with solar and wind output, the need for additional electrochemical or other storage technologies is significantly diminished. This leverages existing infrastructure for grid stability.
The integrated scenario demonstrates the "system value" of coupling sectors. PtG and desalination act as flexible, non-battery storage loads, absorbing surplus renewable generation and improving overall asset utilization, leading to lower costs.
The core of the model is a linear optimization problem minimizing total annual cost $C_{total}$:
$\min C_{total} = \sum_{t,i} (C_{cap,i} \cdot G_{i} + C_{op,i} \cdot g_{i,t}) + \sum_{l} C_{trans,l} \cdot T_l + \sum_s C_{store,s} \cdot S_s$
Subject to:
1. Energy Balance (hourly): $\sum_i g_{i,t} + \sum_s (p_{s,t}^{dis} - p_{s,t}^{ch}) + \sum_l I_{l,t} = D_{t}^{elec} + D_{t}^{PtG} + D_{t}^{Desal}$
2. Capacity Constraints: $0 \le g_{i,t} \le CF_{i,t} \cdot G_i$
3. Storage Dynamics: $E_{s,t+1} = E_{s,t} + \eta_s^{ch} \cdot p_{s,t}^{ch} - p_{s,t}^{dis} / \eta_s^{dis}$
Where $G_i$ is capacity of technology $i$, $g_{i,t}$ is its generation at time $t$, $T_l$ is transmission capacity, $S_s$ is storage capacity, and $D_t$ represents various demands.
Key assumptions include 2005-2009 meteorological data for VRE, technology cost projections for 2030 from literature, an 8% weighted average cost of capital (WACC), and estimated demands for electricity (1813 TWh), water, and gas.
Chart Description (Based on Typical Model Output): A key output chart would show the hourly electricity generation mix for a representative year in the Integrated Scenario (4). The stacked area chart would have time (hours) on the x-axis and power (GW) on the y-axis. Layers would represent: Solar PV (showing strong diurnal cycles), Wind Power (more variable, day and night), Hydropower (acting as a flexible baseload/balancer, filling gaps when solar and wind are low), and thin layers for biomass/geothermal. The top line represents total demand, including direct consumption and loads for PtG/desalination. The chart would visually demonstrate how hydropower dispatch and sector-coupled loads (PtG/Desal) "shave" the peaks of VRE surplus and fill the troughs of deficit, ensuring a constant balance.
Case: Evaluating Grid Centralization vs. Sector Integration
Framework: A two-axis analysis matrix can be used to compare the four scenarios.
Plotting the Scenarios:
Insight: Moving right (better grid) reduces LCOE. Moving up (adding sectors) reduces total system cost and increases resilience. The optimal system design (Scenario 4) requires investment in both transmission infrastructure and cross-sectoral coupling technologies.
Core Insight: This study isn't just a feasibility check; it's a blueprint for leveraging South America's unique legacy asset—massive hydropower—as the linchpin for a next-generation, sector-coupled renewable grid. The real breakthrough is reframing hydro from a mere generator to the continent's primary grid-forming virtual battery, drastically reducing the need for costly new storage and enabling the deep penetration of solar and wind.
Logical Flow: The argument is compelling: 1) Climate risk is making hydropower-dominated systems unreliable. 2) The region has world-class solar/wind resources. 3) The problem is intermittency. 4) Solution: Use existing hydro reservoirs for storage, not just generation. 5) Bonus: Use excess renewable power to make green fuel and water, creating a circular energy-water system. The logic from problem to integrated solution is coherent and addresses economic, technical, and climate adaptation needs simultaneously.
Strengths & Flaws: The model's strength is its holistic, hourly, cost-optimization approach and the groundbreaking integration of PtG/desalination—a step beyond most 100% RE studies which focus solely on electricity. However, the analysis has notable soft spots. The 8% WACC is optimistic for emerging markets; a sensitivity analysis with higher rates (e.g., 10-12%) is crucial. The political and regulatory feasibility of a continent-wide HVDC supergrid is the elephant in the room, glossed over by the techno-economic model. Furthermore, while using hydro as storage is clever, it may conflict with existing water rights, flood control, and ecological mandates—a multi-objective optimization challenge barely touched upon. The study, like many in the field (e.g., Jacobson et al.'s 100% RE plans for the US), excels in technical potential but requires robust companion studies on governance, finance, and social license.
Actionable Insights: For policymakers and utilities in the region, the priority should be: 1) Modernize Hydro Governance: Start reforming water and energy market rules now to enable hydro plants to operate flexibly for grid services, not just bulk energy. 2) Pilot Sector Coupling: Chile's mining industry (needing water and power) or Brazil's industrial hubs are perfect testbeds for PtG/desalination projects. 3) Plan Grid Corridors Strategically: Instead of a full continental grid, focus on key bilateral corridors (e.g., Brazil-Uruguay-Argentina for wind) that build trust and demonstrate benefits. 4) Stress-Test with Real Finance: Run the model with region-specific, risk-adjusted financing costs to get a realistic capex picture. The study provides the technical vision; the next step is building the political and financial architecture to make it real.