Solar curtailment rises in Chile as grid constraints persist

<p class="p1"><span class="s1">Renewable curtailment in Chile reached 6,084 GWh in 2025, up 7.8% year on year, underscoring mounting transmission congestion as the country’s power mix becomes increasingly renewable.</span></p><p><strong>From <a href="https://www.pv-magazine-latam.com/2026/02/23/en-chile-acera-advierte-que-la-matriz-renovable-ya-cambio-el-estandar-operativo-del-sistema-electrico/" rel="noopener" target="_blank">pv magazine LatAm</a></strong></p>
<p>The Chilean Renewable Energy and Storage Association (Acera) said in its 2025 energy system overview that Chile has consolidated a predominantly renewable electricity mix but now faces structural constraints linked to grid bottlenecks, curtailment and rising flexibility requirements. The association identified six indicators expected to shape sector discussions through 2026.</p>
<p>In 2025, the National Electric System (SEN) generated 87 TWh, with renewables accounting for 63.3% of total output. Non-conventional renewable energy (NCRE), excluding large hydropower, represented 42.4% of generation. Including storage, renewables accounted for 65.6% of total supply.</p>
<p>Installed capacity reached 38,613 MW by year-end. NCRE capacity totaled 19,233 MW, equivalent to 49.8% of the system, highlighting the structural shift in the generation mix.</p>
<p>Solar remained the largest renewable technology with 11,717 MW installed, followed by wind at 5,971 MW, exceeding natural gas capacity of 4,865 MW for the first time. Conventional hydropower contributed 20.9% of annual generation.</p>
<p>Curtailment remains one of the most significant indicators of system stress. In 2025, <a href="https://www.pv-magazine.com/2025/10/07/chile-loses-562-million-to-rising-solar-and-wind-curtailment/" rel="noopener" target="_blank">renewables curtailment</a> totaled 6,084 GWh, up 7.8% from the previous year. According to Acera, without these reductions NCRE would have accounted for 49.4% of annual generation instead of the recorded 42.4%.</p>
<p>The association said structural transmission congestion and daytime oversupply indicate that the main challenge has shifted from capacity deployment to system integration and efficient transmission from generation hubs to demand centers.</p>
<p>The Necessary and Urgent Works (ONyU) mechanism was activated for the first time during the year, covering 10 projects comprising six new builds and four expansions, with total investment of $86.4 million. The projects are intended to strengthen short-term security of supply.</p>
<p>Energy storage is emerging as a central flexibility tool. As of December 2025, 575 MW was in operation, 737 MW was under testing and 770 MW was under construction.</p>
<p>By 2027, operational storage capacity could reach up to 9 GW, with an average discharge duration of 4.3 hours and a predominance of hybrid configurations. Acera said storage is expected to provide energy arbitrage as well as operational support and flexibility services.</p>
<p>Electricity demand increased by 0.4% in 2025. Electrification accounts for roughly 23% of total final energy consumption. Acera said accelerating new electricity uses will be necessary to capture renewable value and reduce fossil fuel imports.</p>
<p>The nationwide blackout on 25 February 2025, referred to as “25F,” has placed system resilience and operational continuity at the center of policy discussions. By 2026, performance metrics are expected to emphasize recoverability, coordination and protocols adapted to a high-renewables system.</p>
<p>Acera said Chile’s structural transition toward a renewable-dominated power mix is largely complete. The next phase will depend on regulatory and operational adjustments, with transmission expansion, storage deployment, demand-side management and flexibility services becoming structural components of system performance.</p>