Chile's photovoltaic expansion will depend directly on the deployment of long-duration energy storage systems . The Preliminary Report of the Long-Term Energy Planning (PELP) 2028-2032 projects that between 81% and 83% of new BESS capacity will use eight-hour configurations , while between 16% and 17% will correspond to six-hour solutions.
The document projects that between 27 GW and 58 GW of photovoltaic solar energy will be added over the next 30 years, depending on the scenario. However, this expansion will not occur independently: it will be linked to the cost of batteries, the decommissioning of coal-fired power plants, and the system's capacity to transfer surplus daytime energy to nighttime generation blocks.
“All storage expansion over the planned horizon will be based exclusively on Battery Storage Systems (BESS),” the report states. The plan does not identify any developments in other storage technologies during the period analyzed.
The signal is clear for developers and investors: Chile's next renewable energy phase will be defined by the combination of solar and storage . Solar energy storage systems (BESS) will cease to operate as complementary assets and will assume a structural role in the National Electric System.
The PELP uses as a starting point an estimated storage capacity of 4078 MW by the end of 2026 , with an average duration of 4.3 hours. From there, exploratory scenarios allow for additions of up to 2000 MW per year, while regulatory scenarios raise that limit by between 25% and 50%.
The optimization rules out a significant expansion of short-cycle systems. The model prioritizes batteries capable of shifting large volumes of generation from peak irradiance hours to the afternoon, evening, and early morning.
“Solar energy is no longer expanding aggressively on its own unless it is accompanied by storage,” the technical analysis concludes. The future profitability of new solar parks will therefore depend on the combined cost of generation, storage, and grid connection infrastructure.
This change reflects the evolution of the energy matrix itself. The initial photovoltaic capacity considered in the report reaches 12,015 MW , around 32% of the system's initial installed capacity, while the identified geographical potential exceeds 2.1 million MW.
The PELP does not interpret this potential as directly executable capacity. Its utilization will be conditioned by environmental, territorial, financial, and transmission constraints, in addition to the possibility of storing energy in areas with a high concentration of projects.
In the Mitigated Unfavorable Regulatory Scenario, the system adds approximately 36 GW of photovoltaic capacity between 2043 and 2057 , primarily in Antofagasta and Atacama. At the Cumbre substation alone, operating at 500 kV, the model projects up to 13.2 GW of new capacity.
The early retirement of coal-fired power plants by 2030 accelerates this process. The decommissioning of thermal units reduces dispatchable supply and opens up space for assets capable of delivering renewable energy during periods without photovoltaic production.
This is further compounded by the consideration of a carbon dioxide emissions tax. The increased cost of thermal power generation improves the relative competitiveness of hybrid projects and accelerates investment decisions within the regulatory framework.
“The development of BESS is a necessary condition for the continued expansion of solar energy,” the document states, analyzing the relationship between the two technologies. Without sufficient capacity to shift energy to nighttime, the system will face greater losses and a persistent dependence on fossil fuels.
Antofagasta and Atacama will concentrate a large part of the new installations. Some results project more than 7 GW and up to 9 GW of storage in both regions, in parallel with the expansion of photovoltaics, mining electrification, and the arrival of energy-intensive applications.
The location of the BESS (Basic Energy Storage Systems) will not be random either. The planning favors nodes with available infrastructure, high renewable energy penetration, and thermal power plants in the process of being decommissioned.
“ Storage facilities are strategically installed at the same nodes where coal-fired power plants that are being decommissioned operated ,” the report states. Los Changos appears as one of the most relevant locations due to its proximity to the former Mejillones units and its access to existing transmission networks.
This strategy would allow for the reuse of existing grid connections, maintain injection capacity, and replace coal-fired generation at night. It would also reduce some of the investment required to connect new assets in electrically saturated areas.
The operation will have marked differences between seasons. In summer, the high irradiance will allow photovoltaic generation to cover daytime demand and charge the systems to supply a substantial part of nighttime consumption.
Under these conditions, solar plus BESS systems are increasingly displacing coal, diesel, and gas. Transmission flows can also change direction throughout the day, depending on renewable availability and regional prices.
In winter, lower photovoltaic production will limit the charging level. “ In winter, the batteries cannot fully charge ,” the analysis warns.
The peak demand will be concentrated between 7:00 PM and 1:00 AM , a period coinciding with the drop in solar power generation and peak nighttime energy demands. Outside of this period, the system will continue to require thermal backup, especially during the early morning hours when renewable energy availability is lower.
The PELP also incorporates a systemic inertia constraint and 400 MW of operating reserve , a condition that requires maintaining a certain level of dispatchable generation. Therefore, batteries will reduce fossil fuel dispatch, but will not immediately eliminate the use of gas.
In some long-term scenarios, an additional dynamic emerges: nighttime wind power generation will be sufficient to charge systems during the early morning hours. This complementarity will allow BESS systems to not depend exclusively on photovoltaic surpluses.
The growth of onshore wind energy will reinforce this interaction. Planning estimates additions of between 16 GW and 27 GW over three decades , with sustained expansion in the Maule and Biobío regions.
This development will require reinforcing the Charrúa-Ancoa-Alto Jahuel-Lo Aguirre 500 kV corridor by at least 1750 MVA . Expansions of the 220 kV networks in Antofagasta and Maule will also be necessary, with some sections needing to increase their capacity up to six times.
“ Transmission is confirmed as the critical enabling element for integrating renewable energies and ensuring security of supply ,” the report states. BESS will alleviate congestion and displace injections, but will not replace structural grid infrastructure.
Green hydrogen and data centers increase pressure on the north
Emerging electricity demand will further expand the market for long-duration systems. Green hydrogen, data centers, and mining electrification will concentrate new requirements in the north, precisely where the system anticipates the greatest addition of photovoltaic generation.
In the Mitigated Regulatory Trend scenario, supplying green hydrogen electrolysis requires 6,146 MW of photovoltaics in Kapatur and 4,120 MW of BESS in Los Changos . This demand would also necessitate expanding the area's grids by almost 4,376 MW.
“ The production of green hydrogen through electrolysis will constitute a gigantic emerging electricity demand ,” the plan warns. Its most visible impact would occur from the 2040s onward, driven by heavy transport, mining, and industrial thermal processes.
Data centers will also gain importance. Their installed capacity will increase from 198 MW in 2024 to 594 MW in 2030 and 900 MW in 2057 , according to projections included in the report.
The Mitigated Unfavorable Regulatory Scenario also adds 500 MW of demand associated with new projects in Antofagasta by 2030. That additional load would reach 1 GW in 2057 .
The combination of these energy sources will modify the regional demand profile. It will no longer be simply a matter of integrating large volumes of renewable energy, but of guaranteeing continuous supply for activities with high load factors and lower interruption margins.
The plan estimates that at least 83% of the country's annual power generation will be supplied by solar and wind energy by 2057. This will require close coordination between new capacity, long-duration storage, transmission, and operational backup.
The Preliminary Report will remain open for comments from the Register of Interested Parties until August 24, 2026. Afterwards, the Ministry of Energy will publish the Final Report, receive further comments, and proceed towards the final document and the Planning Decree.
For the market, the conclusion is clear: Chilean photovoltaic expansion can no longer be analyzed separately from battery storage systems (BESS ). Six- and eight-hour batteries will be necessary to capture surplus energy, reduce emissions, replace thermal generation, and meet the growing industrial loads in the north.