METLEN sells 725MWh Chilean hybrid project

METLEN has agreed to sell its Tamarico II hybrid renewable-energy project in Chile’s Atacama Region to Copec through subsidiary Copec Flux, transferring a development that combines 165MW of photovoltaic generation with 725MWh of battery energy storage.

The storage component can be expanded to 925MWh, giving the project a substantial energy reservoir alongside its solar plant. METLEN has not disclosed the battery’s power rating, connection capacity, equipment suppliers, construction status, or commissioning timetable in the sale announcement.

The missing power figure prevents a reliable calculation of battery duration. Megawatts describe the maximum rate at which a storage system can charge or discharge, while megawatt-hours describe the quantity of energy available; 725MWh therefore establishes the size of the reservoir but not how quickly that energy can be delivered.

Tamarico II nevertheless reflects an increasingly important operating model in Chile, where large photovoltaic resources are being combined with storage to alter the timing of solar exports. Rather than sending all available generation to the network during daylight hours, a hybrid plant can divide production between immediate export and battery charging.

That flexibility is particularly relevant in northern Chile because the country has developed substantial solar capacity in regions with exceptional irradiance but limited local demand. Transmission congestion and high simultaneous photovoltaic production can reduce the value of electricity during parts of the day or force available renewable output to be curtailed.

A battery gives the operator another destination for that energy while charging capacity remains available. Stored electricity can then be discharged later, when photovoltaic production has fallen and market conditions or contractual requirements make export more valuable.

The arrangement does not eliminate curtailment automatically. A full battery cannot absorb further solar output, and its charging power may be lower than the amount of generation exceeding the grid export limit during a particular period.

Plant controls therefore have to balance photovoltaic output, battery state of charge, the electrical connection, market schedules, equipment limits, and expected generation later in the day. Charging too aggressively can leave no space for a subsequent solar surplus, while preserving too much headroom can leave the battery underused if expected generation fails to materialise.

Forecasting consequently becomes part of the electrical operating strategy. Irradiance, temperature, inverter availability, battery efficiency, electricity prices, network constraints, and expected demand all influence the optimum charge and discharge schedule.

The hybrid arrangement also increases the complexity of the substation and plant-control system. Photovoltaic inverters and battery power-conversion equipment have to operate through coordinated protection, metering, communications, export controls, auxiliary supplies, and high-voltage interfaces rather than functioning as two unrelated installations occupying the same site.

Chile is already bringing comparable configurations into construction. ContourGlobal’s Los Maitenes development combines approximately 131MWp of photovoltaics with a 90MW/360MWh four-hour battery and a power-purchase structure covering daytime and night-time delivery blocks.

Los Maitenes publishes both battery power and energy, allowing its four-hour duration to be established directly. Tamarico II currently provides only the storage-energy figure, so describing it as a two-hour, four-hour, or longer-duration project would go beyond the information disclosed by METLEN.

The 725MWh figure still places it among substantial storage developments. Expansion to 925MWh would add another 200MWh of energy capacity, potentially giving the operator greater ability to shift solar production across time, although the value of that expansion will depend on the battery power rating and grid connection available to use it.

Copec Flux will acquire the project as part of Copec’s expansion into renewable generation and energy storage. METLEN says the transaction extends a relationship between the two groups that began three years ago and provides a basis for further collaboration on Chilean renewable and storage investment.

The sale also sits within METLEN’s Asset Rotation model. The company develops renewable projects and monetises selected assets through sales, allowing capital to be recycled into further development rather than retaining every project through its full operating life.

For the purchaser, however, the eventual performance of Tamarico II will be determined by engineering and market operation rather than the ownership model used to complete the transaction. Battery degradation, conversion losses, availability, warranties, connection restrictions, and dispatch strategy will all influence how much usable flexibility the plant provides over time.

Cell degradation is particularly important where storage is used regularly to shift daily solar output. Repeated cycling gradually reduces available energy capacity, requiring operating limits, augmentation, replacement planning, or contractual allowances if the project is expected to maintain a defined level of performance throughout its commercial life.

METLEN already has engineering exposure to those issues in several markets. Its recent Penn BESS contract in Britain includes electrical and civil balance-of-plant work and the grid connection for a 129MW/362MWh project, while its wider storage portfolio covers standalone and co-located assets.

Chile adds a different system challenge because storage development is becoming closely tied to the economics of a rapidly expanded solar fleet. As more batteries seek to charge during low-value daylight periods and discharge into evening peaks, competition can compress the same price spreads that originally attracted investment.

Projects will increasingly depend on location, connection rights, availability, operating efficiency, and contract structure rather than storage capacity alone. A large battery with restricted network access or an unsuitable dispatch strategy can leave part of its headline energy capacity commercially idle.

Tamarico II therefore enters the next stage of ownership with two major ratings known and several of the decisive engineering parameters still undisclosed. Its 165MW solar plant and 725MWh storage reservoir establish substantial scale; battery power, connection design, construction programme, and commissioning will determine how that scale behaves on Chile’s electricity system.