[Report] Visiting Korea's Largest 'Solar City Solar Power Plant'... Complete Grid System and Safety Measures in Place

98MW Scale PV and 306 MWh ESS Integrated Installation
Electricity Supply to 26,875 Households in Haenam and Yeongam Based on 400KWh per Month
Domestic Module Price Competitiveness 'Challenge'... "10% More Expensive Than Chinese Products"
Resident Profit Sharing and RE100 Pilot Project Still Pending... "Expecting PPA Law to Pass in National Assembly"

A panoramic view of the solar panels at the 'Solar City Solar Power Generation Facility Complex' located in Guseong-ri, Sanim-myeon, Haenam-gun, Jeollanam-do. (Photo by Korea Energy Information & Culture Foundation)

[Asia Economy Reporter Moon Chaeseok] On the 30th of last month, heading toward late autumn, the 'Solarisido Solar Power Generation Facility Complex' located in Guseong-ri, Sanim-myeon, Haenam-gun, Jeollanam-do. As the largest solar power generation facility complex in Korea, it features solar panels installed in neat rows on a scale too vast to capture in a single glance.

After driving about 20 km (approximately 25 minutes) from Mokpo Station and spotting the 'Solarisido' sign, one must travel an additional 5 minutes by car on a single-lane unpaved road to reach the 154Kv substation and the Energy Storage System (ESS) facility.

At the entrance of the complex where the sign "Solarcido Complex" is installed, it takes an additional 5 minutes by car to see major facilities such as the substation. A puddle of water next to the solar panels is also noticeable. It is said that an "agricultural business" is planned for this space in the future. (Photo by Moon Chaeseok)

At 11:38 a.m., when stepping onto the Solarisido complex grounds, the temperature was 16.8℃ with a light breeze. It was hard to find workers anxiously trying to gather sunlight during the day. This is because up until 4 p.m., it is possible to collect about 90% of the day's electricity. The system is equipped to send the electricity collected from sunlight to Korea Electric Power Corporation (KEPCO) without issues until 5 p.m.

The Solarisido complex is the largest solar power generation facility in Korea. It was completed in March on a 480,000-pyeong site and consists of a 98MW solar power complex and a 306MW ESS power complex. It produces 129GWh of electricity, enough to supply 26,875 households in the nearby Haenam and Yeongam counties (assuming each household uses 400KWh per month).

"Fully charged by 2 p.m... Power sent to KEPCO until 5 p.m."

Solarcido New and Renewable Energy Operation Center. The electronic display board divided into three sections featuring photovoltaics (PV) and ESS on the left, and a 154Kv substation stands out. (Photo by Moon Chae-seok)

After visually confirming the scale of the complex, we visited the 'Solarisido New and Renewable Energy Operation Center' to check whether the electricity collected from sunlight is properly managed and transmitted. The Solarisido complex has a fully integrated system capable of 'production, charging, and transformation' all at once. Electricity at 22,900V is managed in an outdoor electrical room on-site and is transmitted to KEPCO through a substation. Safety is ensured by burying cables underground ('undergrounding') over approximately 7.1 km from the Solarisido substation to the nearby Samho substation in Yeongam-gun.

The most striking feature at the operation center is the electronic display divided into three sections for photovoltaic (PV) solar power, ESS, and the 154Kv substation. It allows real-time monitoring of output status, power generation, and ESS battery charge levels. As of 12:44 p.m., the PV output was 77.073MW. On that day, operations began around 9:40 a.m., recording 297MWh of power generation over about three hours. The ESS battery was 62.2% charged.

Kim Dongha, the site manager of Solarisido Solar Power Generation Project, explained, "Electricity generated by the solar power facility primarily goes into the ESS. The ESS typically charges from 10 a.m. to 4 p.m. Given the current status, we expect to complete 90% charging around 2 p.m., fulfilling today's production volume."

Solarcido Solar Power Plant Outdoor Electrical Room. (Photo by Korea Energy Information & Culture Foundation)

The ESS is charged and managed up to a maximum of 90% according to government safety standards. According to the Ministry of Trade, Industry and Energy's 'Renewable Portfolio Standard (RPS) Management and Operation Guidelines,' outdoor ESS units can only be charged up to 90% for safety reasons. Exceeding 90% results in the renewable energy certificate (REC) weighting for that month being adjusted to zero. Currently, the REC weighting for solar-linked ESS is 4.0.

The PV at Solarisido can operate for another 20 years (until December 2039), and the ESS for 15 years (until February 2035). The reason for the limited periods of 'PV 20 years and ESS 15 years' is that these durations were set when the initial contract was made with KEPCO.

20℃ Storage Room Smelling of Metal Instead of Sparks... Korea's First Operation of 20 Separate ESS Buildings

The Solar Cido solar power plant is the first in the country to operate by distributing ESS installations across multiple buildings. Interior view of the ESS building. (Photo by Moon Chae-seok)

After confirming the system for generating and sending electricity, we examined the ESS safety management system. ESS units are generally known to produce sparks due to the lithium-ion batteries installed inside.

It was notable that the ESS, composed solely of Samsung SDI products, is managed by dividing it into 20 separate buildings. Each building handles 15,773KWh of ESS. This is the first time in Korea that ESS units are managed separately by building. A total of 9 million cells densely fill the 20 ESS buildings.

All ESS units in the Solarcido solar power complex use Samsung SDI products. (Photo by Moon Chaeseok)

We entered one of the ESS buildings. To prevent the possibility of thermal runaway, the temperature inside the ESS building is maintained at a certain level, and racks are distributed across multiple buildings. Box-shaped racks are lined up like lockers. Each rack contains 25 modules assembled from battery unit cells called 'cells.'

There was a faint metallic smell. A weak air conditioning breeze was felt. Manager Kim, who accompanied us, explained, "Regardless of the season, the temperature is maintained around 20℃. In case of fire, the structure is designed to consume the fire inside the building, and components like the power conversion system (PCS) are installed outside the building."

Inside this ESS rack, there are 25 modules assembled from battery unit cells called 'cells.' (Photo by Moon Chae-seok)

An official accompanying us on-site hinted, "Access to ESS buildings is often restricted due to sparks caused by heat transfer issues." On this day, the group, including local staff, numbered about 30 and freely moved in and out of the ESS buildings.

Regardless of the season, the temperature inside the ESS building must be maintained at 20℃ to reduce the risk of ESS sparks and fire hazards caused by heat exchange. (Photo by Moon Chae-seok)

Measures against fire (ESS) and water (flood) damage have also been prepared. In the event of heavy rain, the water level is controlled at the nearby Yeongam Lake's embankment. Water is drained by lowering the sluice gates. Soil has been piled up 1 meter high along the outer roads. During foundation work, piles measuring 2.8 meters were also driven.

Module Prices 10% Higher than Chinese Products... "Supplied by Domestic Companies"

Although the Solarsido solar power complex is grand in scale, achieving '100% localization' remains a challenging reality. (Photo by Korea Energy Information & Culture Foundation)

Although it is the largest solar complex in Korea, the modules are not 100% domestically produced. Officials at the complex acknowledged that this is realistically difficult due to price differences. They use modules from the Chinese company JinkoSolar and the domestic company Hansol Technics. The efficiency is similar, but price is the issue.

The overall domestic component localization rate within the Solarisido complex is 92%, but the solar modules themselves are only 60%. In terms of usage, JinkoSolar accounts for 58.1MW (59%), and Hansol Technics for 40.3MW (41%). The overall 92% localization rate is attributed to the exclusive use of Samsung SDI products for the ESS.

When asked why Chinese modules were purchased, Manager Kim explained, "It was not easy to receive domestic modules for 100MW, about 260,000 units, within the construction deadline set at the start of the project. We first received modules from Hansol Technics and supplemented the shortfall with Chinese products."

A Hansol Technics representative said, "Considering labor costs and others, the price difference between domestic and Chinese products is about 10%. If domestic is 100 won, Chinese is about 90 won."

Low Progress in Agrivoltaic Power Plant Resident Profit Sharing and RE100

The Solarsido solar power complex is too vast to capture with the naked eye. A puddle of water has formed next to the panels. There are plans to harvest crops in this area in the future and increase residents' income. (Photo by Moon Chaeseok)

The progress of the agrivoltaic power project was low. Below the grand solar complex where panels are spaced 4.5 meters apart in neat rows, only dirt fields and small puddles were visible. Murky water had pooled, and bird droppings were spotted. There was no sign of crops growing vigorously or residents actively coming and going.

It seemed there was a long way to go to achieve the project plan of "creating jobs for local residents during the off-season through module replacement and weeding work on 42,000 pyeong of agrivoltaic land."

Park Ki-young, Executive Director of New and Renewable Business Development Team 1 at Hanyang (a construction affiliate of the Boseong Group participating in the Solarisido development project), explained, "Although farming is being done on salt-damaged farmland, the high alkalinity means farming has not yet progressed properly."

The progress rate of the RE100 pilot complex project was not high. The site where the complex is planned to be built. (Photo by Moon Chae-seok)

The 'RE100 (campaign to replace 100% of power consumption with renewable energy) pilot complex project,' part of Jeollanam-do's announced 'Blue Economy' initiative, also appeared undeveloped. The land was left vacant. It is a project to build 800MW of ground-mounted solar power on a 4.29 million-pyeong site in the nearby Budong district. The goal is to supply 1GW of renewable energy and realize 'basic income implementation (sharing 300,000 to 500,000 won per household monthly from power generation profits), job creation, population inflow expansion, and regional economic revitalization.'

RE100 pilot complex project plan. (Photo by Moon Chae-seok)

Officials from Hanyang and Jeonnam Province admitted they are struggling to attract participating companies. They have not received concrete participation responses from large corporations such as Samsung Electronics, SK Hynix, and LG Chem, which have hinted at joining RE100. The reality is that the RE100 system will only be implemented in Korea starting January next year. The renewable energy power purchase transaction system, which must go through KEPCO, remains a burden.

A Jeonnam Province official said, "For the RE100 dedicated complex project to gain momentum, the passage of the Power Purchase Agreement (PPA) Act, which was primarily proposed by Representative Kim Seong-hwan of the Democratic Party, is necessary. Allowing autonomous renewable energy contracts between renewable energy suppliers and companies will help encourage domestic companies to participate in RE100."