The South Korean government’s renewable energy deployment plan aims to increase the share of electricity generated from renewables to 20% by 2030. To reach this goal, the rate of photovoltaic (PV) installation will accelerate in the coming years. This energy transition creates a new challenge: PV wastes. This study estimates the amount of PV waste generated, the material composition of PV waste, and the amount of recyclable metals in South Korea by 2080 under four different scenarios (combining shape parameters of 5.3759 [regular-loss] and 3.5 [early-loss] with PV module lifespans of 25 and 30 years) using the Weibull distribution function. The annual waste generated will fluctuate over time depending on the scenario, but between 4299 and 5764 thousand tons of PV waste will have been generated by 2080. Under the early-loss/25-year lifespan scenario, annual PV waste generation will increase to exceed 130,000 tons in 2045, then decrease through 2063 before increasing once again. The fluctuation in annual PV waste generation appears stronger under regular-loss scenarios. An appropriate system for the monitoring, collection, and storage of PV waste needs to be arranged even before the volume becomes high enough for recycling to be economically viable. International cooperation could be a way to maintain the PV waste stream at an economically feasible scale. It would also be a good idea if the PV module could be designed in a way that would enable easier recycling or reuse.

Given emerging concerns about climate change, low-carbon energy transition is advocated and promoted. Non-energy use of fossil fuels accounted for 8.9% of the world’s total final energy consumption in 2015. Non-energy use intensity does not show an evident reduction, while energy intensity as fuel per dollar of gross domestic product has decreased thanks to energy transition efforts such as energy efficiency promotion and renewable energy expansion.  This study conducted an extensive review of the circular economy and energy transition frameworks, and found that the energy transition framework has a critical gap, so it cannot provide a foundation for investigating non-energy use. This study suggests that the energy transition discourse needs to be extended to incorporate the transition of non-energy use and the achievement of a closed loop of non-energy use, which is part of the circular economy framework. The coordinated circular economy–energy transition approach could bring in synergistic effects, such as promoting circular economy activities among industries, reducing energy demand, and attaining additional greenhouse gas mitigation potential.

South Korea’s electricity sector is at a crossroads. A transition to a safer and more ecologically friendly electricity system, one that would reduce dependence on coal and nuclear power plants and produce more electricity from new and renewable energy, is being suggested and actively discussed. Changes to these two pillars of the electricity sector, which have enabled a reliable and affordable electricity supply, present environmental and economic concerns. Will this shift adversely affect the electricity sector’s greenhouse gas emissions? Will this change be economically feasible? To answer these questions, this study explored the environmental and economic implications of changes in the South Korean electricity sector using the Long-range Energy Alternative Planning model. Despite using very conservative assumptions about the generation of new and renewable energy, the study found an economically feasible path that would yield less greenhouse gas emissions than the reference scenario. This path, which involved closing old coal-fired power plants, phasing out nuclear power, and reducing demand, shed light on the green shift in the electricity sector. Decreasing electricity demands should be discussed and considered along with this change. The study’s implications could apply to other countries as they investigate the economic and environmental implications of various policy options for transitioning to safer and more ecologically friendly sources of electricity.

Solar photovoltaics (PV) deployment is not easy in dense urban areas because there is little space for the installation. Furthermore, tenants have few incentives to install PV panels because they frequently relocate, and most PV facilities are nonremovable. To address these factors, this study reports on an innovative model that collectively installed 260 W of mini-PV on the balconies of almost all the households in two high-rise apartment complexes in Seoul, South Korea. This project was unique in that it established energy commons in a community using private space. This study found that economic and social factors significantly influenced community-internal or micro factors, which in turn affected the success of the community energy project. Economic factors such as the expected economic benefit and residents paying no direct installation costs shaped the initial conditions for the commencement of the project. Leadership played a key role by speeding up the process, relieving residents’ concerns and distrust. This study introduced an innovative community energy model that can be referenced by megacities and communities. It provides opportunities for enhancing awareness of energy transition via on-site energy production using renewable energy and allows even communities that have insufficient common space to build energy commons.

Bio-energy is a research field that is of worldwide interest. South Korea, which imports all of its heavy fuel oil for consumption, passed a new law allowing bio-heavy oil made from animal fat, by-product of biodiesel processes, palm oil, and other leftover oil to be used to generate electricity in place of heavy fuel oil. As there is lack of policy research with respect to liquid biofuels, the purpose of this study is to define the bio-heavy oil industry in South Korea and to investigate the economic effects of bio-heavy oil. An input–output analysis model was used and demonstrated that the production-, value-added-, import-, and employment-induced effects of the bio-heavy oil industry were larger than those induced by the heavy fuel oil industry. As the import of fuel by the heavy fuel oil industry was greater than the bio-heavy oil industry, the import substitution effect of the bio-heavy oil industry was found to be greater. This resulted in a positive value for the net-induced effect of the bio-heavy oil industry. When considering the global concern with respect to the development and expansion of biofuel feedstock, this study shows the possibility of transforming heavy fuel oil plants distributed around the world into renewable energy sources.