South Korea’s solar industry is entering a decisive phase. A decade ago, growth was underpinned by feed-in tariffs, very generous subsidies and an industrial policy designed to position Korean manufacturers as global players.

Today, the solar landscape looks markedly different in the politically turbulent nation. Domestic wafer and module producers have long-since lost ground to cheaper Chinese imports, as subsidy frameworks have become markedly less generous, and project developers face increasingly complex issues over permits and land-use rules.

For the country’s engineering, procurement and construction (EPC) firms - the companies that design, build and then maintain solar projects, the challenge is more and more about how to adapt.

Among the domestic players, GRANDSUN stands out as an example of how a mid-sized EPC is seeking to evolve. Founded in 2005, the company presents itself as a ‘total solution’ provider. Its offering spans the entire solar value chain: site assessment and permitting, system design and procurement, construction and commissioning, followed by long-term operation and maintenance.

The firm maintains regional branches in Busan and Gyeongbuk, positioning itself as a national player with local reach – a reach that stood out at the late-August 2025 Korea Energy Show in Busan with a large setup to promote the firm’s prominence in a market where permitting hurdles and regional compliance can, and often does stall projects.

Financially, GRANDSUN is no start-up. Employing around 150 staff, it has carried out over 500 commercial-scale projects and thousands of residential installations since entering the market. In 2024 sales revenue hit the KRW110bn ($78.4mn) mark.

Yet size alone is no guarantee of survival in South Korea’s crowded EPC field. Chinese modules now dominate imports as they do across much of East and Southeast Asia, in the process squeezing margins for local players that must compete on cost. At the same time in South Korea, the domestic solar manufacturing base has weakened putting GRANDSUN and their competitors in a bind. Hanwha Qcells, once a flagship Korean producer, has downsized facilities in South Korea in recent years in response to global overcapacity. For EPCs, especially Korean EPCs, this creates a paradox - modules are cheaper - but differentiation becomes harder as clients focus primarily on price.

GRANDSUN’s answer to this issue according to staff manning the booth in Busan, has been to pivot towards service, warranty and digitalisation – the nuts and bolts of EPC quality.

Partnerships with firms such as POSCO, IKEA, DENSO and Korea Aerospace Industries help significantly.

So do marketing materials issued by the firm stressing AI-assisted remote monitoring, predictive maintenance and digital tools aimed at boosting output and over time reducing lifecycle costs.

These concepts at GRANSUN and other South Korean EPC names of note are pitched at commercial and industrial clients for whom performance guarantees and long-term asset value are ultimately more important than initial installation costs.

It is a strategy reflecting a broader shift in demand. With feed-in tariffs scaled back, customers in both the corporate and residential sectors are more motivated by long-term energy self-sufficiency, electricity cost savings and in many cases sustainability targets. Companies across Korea subject to RE100 pledges, which require sourcing 100% renewable electricity, want partners who can deliver turnkey projects bundled with compliance and monitoring tools.

GRANDSUN also emphasises financial credibility. In 2021 the company carried a BBB+ domestic credit rating, a mid-tier but very respectable grade that signals reliability to potential corporate clients. Its corporate philosophy of “serving the nation through business (and) contributing to the country and society through enterprise” reflects an effort to align business identity with social responsibility, a recurring theme in South Korea’s renewables discourse.

The challenges ahead, however, are now more structural. South Korea’s solar build-out remains constrained by regulatory bottlenecks and limited available land in a mountainous nation of over 50mn. Rooftop projects, once seen as a growth driver, face their own hurdles in building code compliance and local opposition in some areas with larger-scale ground-mounted projects increasingly difficult to site. Against this backdrop, leading EPCs like GRANDSUN must extract margin from efficiency, speed of execution and long-term services rather than from scale alone.

As such, the firm’s trajectory also underlines the competitive pressures facing mid-sized EPC companies. Unlike the few large chaebol-affiliated entities that can leverage balance sheets and global supply chains, or the smallest local installers who operate with minimal overheads, companies like GRANDSUN sit in the middle. Their survival depends on combining the project execution capacity of a contractor with the consulting expertise of an energy advisor.

For Korean policymakers, the experience of GRANDSUN and its peers offers lessons.

South Korea’s renewable targets of 21.6% of generation from renewables by 2030, under current plans will only be achieved with a robust EPC sector capable of delivering and maintaining projects at scale.

Yet across South Korea and increasingly so across neighbouring Japan too, the policy environment has too often focused on headline capacity additions rather than the health of the companies that must deliver them. Without attention to financing structures, permitting reform and support for digital O&M capabilities, many EPCs will remain exposed to wafer-thin margins and volatile demand.

Sources speaking to AsiaElec indicate that GRANDSUN is not immune to these risks and its reliance on domestic projects leaves it vulnerable to shifts in Korean policy and corporate demand cycles just like everyone else.

One way to counter this and at least put in place a financial safety net should the domestic solar sector continue to contract, would be to establish an international presence of note. Until it does, and until GRANDSUN and other South Korean EPC firms spread their wings overseas to such an extent that contractions in one market can be offset by sales in another, long-term survival will only depend on how quickly the industry - and government policy - can address the structural issues limiting South Korea’s solar build-out.

For now, GRANDSUN is a successful survivor in a highly competitive field. Only on the back of sustained efforts by lawmakers in Seoul to push the renewables envelope to bigger and better things across South Korea will it keep ahead of the curve.