The ratio of mountainside solar farms has declined from 39.2 percent in 2017 to 32.5 percent in 2018 and 31.5 percent in 2019, according to the Ministry of Industry, Trade and Energy.

However, the scale of such solar farms has increased. In 2016, 529 hectares of mountainside solar farms were built. After President Moon Jae-in took office, 1,435 ha, 2,443 ha and 1,024 ha of solar farms were newly built in 2017, 2018 and 2019, respectively.

As of Sunday, 12 landslides have occurred at mountainside solar farms amid the longest and deadliest monsoon season in South Korea.

Meanwhile, the ratios of solar farms built on farmlands and other locations -- such as orchards and pastures -- are on the rise, from 25.5 percent and 11.7 percent in 2017, respectively, to 30.3 percent and 12.6 percent in 2019. 

By Kim Byung-wook (kbw@heraldcorp.com)