Solar Power Could Trigger Blackouts, Warns Nuclear Experts

An analysis shows that if solar power generation expands to account for 50% of the nation’s energy mix by 2050, as per the government’s carbon neutrality scenario, the cost of installing energy storage systems (ESS) to store the electricity generated from solar power alone would amount to at least 464 trillion won. This is equivalent to 70% of this year’s national budget. Experts warn, “Excessive increase in solar power share could lead to power grid instability, resulting in higher electricity bills and potentially causing nationwide blackouts,” advocating for an increase in nuclear power generation.

On May 15, 14 related organizations, including the Korean Nuclear Society and the Korea Nuclear Industry Association, visited the Democratic Party’s central headquarters in Yeouido, Seoul, to deliver a “National Nuclear Policy Proposal” containing these points to the campaign of Lee Jae-myung, the Democratic Party’s presidential candidate. The nuclear industry, academia, and research community plan to deliver this proposal to the campaigns of Kim Moon-soo, the People Power Party’s presidential candidate, and Lee Jun-seok, the Reform Party’s presidential candidate, as schedules are coordinated.

The approximately 90-page proposal comprehensively covers the need for nuclear power expansion, workforce augmentation, and power grid stabilization. Experts particularly pointed out that if nuclear power is tabooed and renewable energy is overly emphasized in the transition to zero-carbon energy, cost burdens will inevitably surge. Since solar power only produces electricity during the day and less when the weather is cloudy, massive ESS installations are needed to store excess electricity, which is expected to incur enormous costs.

According to the proposal, assuming solar power generation accounts for 50% of total power production in 2050 and the average daily power demand is 140GW (gigawatts), the ESS capacity needed to store excess solar power for a day would be about 1,160GWh (gigawatt-hours). This is equivalent to the amount of electricity 330,000 households can use in a year. The nuclear industry explained, “If the installation cost for 1GWh capacity ESS is 400 billion won, a total of 464 trillion won would be needed,” adding, “To prepare for cases where solar and wind power remain low for several days, much more storage facilities would be required.”

The nuclear industry emphasized, “Even if the cost of solar facilities significantly decreases in the future, the operational cost of solar power generation, including storage costs, will be at least twice that of nuclear power.” According to the Korea Power Exchange, as of March this year, the unit cost of solar power generation was 114.7 won per kWh (kilowatt-hour), 1.5 times that of nuclear power (75.7 won), and this gap widens considerably when considering additional costs like storage. Experts point out that such cost increases will inevitably be passed on to power consumers, including households and businesses.

Increased power grid instability is also a major concern. Power production must always be stably regulated to match demand, neither excessive nor insufficient, as too much power production can overload the grid, leading to blackouts. However, renewable energy sources like solar and wind power, whose output depends on weather conditions, are difficult to control, causing grid instability. The proposal states, “Increased power grid instability and decreased electricity quality will adversely affect semiconductor, battery, and precision equipment industries,” warning that “in the worst case, a major blackout could occur.”

Experts emphasized the need for a realistic energy mix policy combining renewable energy and nuclear power to achieve carbon neutrality while maintaining grid stability. The nuclear industry argued, “Unlike Europe, carbon neutrality relying solely on renewable energy is impossible in Korea, which has an isolated power grid, high population density, no indigenous energy resources or hydropower, and focuses on manufacturing and IT industries,” suggesting, “As nuclear power is Korea’s most advantageous zero-carbon power source, large-scale nuclear power plant construction should be significantly expanded to increase the nuclear share to 40% in the 2040s and 50% in the 2050s.” According to the Ministry of Trade, Industry and Energy, the share of nuclear power in total power generation last year was 31.7%.

Urgent policy tasks for the development of the nuclear industry include: 1) expanding the workforce, 2) extending the continued operation permit period by 10 years, 3) expanding nuclear power plant sites and transmission networks, 4) establishing nuclear power supply plans, 5) improving the licensing system and regulations for innovative small modular reactors (i-SMR), and 6) reorganizing the Nuclear Safety and Security Commission. The nuclear industry particularly emphasized, “Due to uncertainties in nuclear policy, the number of nuclear engineering students last year hit a record low of 2,156, and 27.8% of the nuclear industry cited ‘securing technical personnel’ as the biggest internal constraint to ensuring competitiveness,” appealing for “long-term policy support to attract and nurture excellent talent.”

The nuclear industry also stressed, “With the rapid increase in power demand for future industries such as artificial intelligence (AI) and data centers, the current passive power supply and demand planning will struggle to respond in a timely manner,” emphasizing the need for “establishing nuclear power supply plans linked to advanced industry development strategies, improving the licensing system for timely i-SMR construction, encouraging private sector participation, supporting domestic demonstration, and providing tax benefits to participating companies.”