Integrated Solar Combined Cycle (ISCC) is a hybrid system that integrates both solar thermal power and fossil fuels. ISCC may alternate system variables, but they mainly consist of three major components: a Combined Cycle Gast Turbine (CCGT), Solar Steam Generator (SSG) and a solar field. In some cases, they integrate Natural Gas-Fired Combined Cycle (NGCC) and Concentrated Solar Power (CSP).

ISCCs can achieve efficiency rates of around 67%, which is 10% more when compared to a conventional combined cycle plant. It’s also possible to combine CSP plants with solar PV, wind, or small hydropower plants, which will replace fossil fuel share for alternative sources, with goals of decreasing Greenhouse Gas (GHG) emission.¹

In an example system built in Chile, utilization of Solar PV can provide cheaper energy during the day, while the CSP system starts generation in the afternoon with significant storage capacity, and in turn provides secure and stable energy power.

The early concept of ISCC was proposed by Luz Solar International in the early 1990s, and materialized into the Archimede Project in Sicily Italy, consisting of two (2) 380 MWe gas-fired combined cycle power plants and a 5 MWe parabolic solar field which uses molten salts as heat transfer fluid (HTF).²

In the Indonesian market, utilization of ISCC can bring a few positive impacts for Indonesia’s sustainability and reliability in terms of energy / electricity sources, such as:

Diversification of Energy Sources

As Indonesia still relies heavily on fossil fuels, ISCC power plants can add diversity so the pre-existing energy mix by integrating solar energy with conventional fossil fuel-based power generating schemes. Diversification can reduce the country’s dependence on finite fossil fuel resources.

Renewable Energy Integration

As part of Net Zero target, Indonesia aims to reach 23% of national energy mix in 2025 to consist of renewable energy sources. ISCC systems can help integrate renewable energy use in Indonesia.

Cost Saving and Efficiency Improvements

ISCC systems can potentially lower electricity generation costs over the long term, as solar power is free and abundant. If the infrastructure for solar power utilization has been set, some fuel costs associated with conventional power generation can be offset towards ISCC use.

Grid Stability and Reliability

As solar energy utilization is mostly intermittent, integration with conventional gas / steam turbines in ISCC hybrid plants can provide a more stable and reliable power output, resulting in mitigation of variability of renewable energy.

Environmental Impact

Like most renewable energy generators, ISCC plants can mitigate GHG emission production when compared to conventional fossil fuel plants, which contributes to improved air quality and public health, especially amidst the pollution cases in 2023-2024 over West Java Islands.

Overall, ISCC systems may lead to a more sustainable, highly resilient, and cost-effective energy generation system, benefiting both the economy and the environment.

References:

1. L. Souza and A. Cavalcante, “Concentrated Solar Power deployment in emerging economies: The cases of China and Brazil.” https://www.sciencedirect.com/topics/engineering/integrated-solar-combined-cycle-system
2. B. Alqahtani and D. Patino-Echeverri, “Integrated Solar Combined Cycle Power Plants: Paving the Way for Thermal Solar.” https://sites.nicholas.duke.edu/daliapatinoecheverri/files/2015/09/ISCC.pdf

This article is written by :
Reza Radinka
Sales & Marketing staff

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