Ministry of Industry: "The Cause of This Summer's Peak Demand Error is 'Solar Power'... Will Strengthen Predictability"

Peak Summer Demand on August 7 at 93.6GW... Expected Demand 92.9GW
Heavy Rainfall in Solar Power Dense Areas During Peak Lowers Utilization
"Expanding Renewable Energy Bidding System and Lowering Market Participation Obligations"

The government has decided to actively promote improvements to related systems to minimize the variability of solar power generation, which is affected by weather conditions. The Ministry of Trade, Industry and Energy analyzed that the reason the peak power demand this summer exceeded projections was due to lower-than-expected solar power generation during peak hours, and plans to include measures to enhance the predictability of renewable energy in the "Power System Supply and Demand Roadmap" scheduled for release next month.

According to the Ministry on the 14th, the maximum power demand this summer was 93.6GW at 5 p.m. on the 7th, exceeding the forecast (92.9GW) by 0.7GW.

(Photo)

An official from the Ministry explained, "At the peak power time of 5 p.m., the solar utilization rate was initially expected to be around 32%, but localized heavy rain occurred in solar power-dense areas such as Naju, causing the utilization rate to be lower than expected. Since 72% of solar power is unmetered and deducted from demand, the lower utilization rate led to an increase in demand."

Solar power facilities are classified according to transaction methods as ▲market-participating solar ▲Korea Electric Power Corporation (KEPCO) direct power purchase agreement (PPA) ▲self-generation (BTM). The facility scale is approximately 27GW in total, with market participation at 7.6GW (28%), KEPCO PPA at 14.7GW (55%), and BTM at 4.7GW (17%).

Market-participating solar power is acquired in real-time and included in power supply, but unmetered solar power, which accounts for 72% of solar power?namely KEPCO PPA and BTM?is not metered and appears as a deduction from power market demand. Since KEPCO PPA and BTM are reflected in demand rather than supply, a decrease in solar utilization reduces the deduction amount, thereby increasing demand.

Accordingly, the government plans to improve systems to enhance the predictability of renewable energy, such as integrating unmetered solar power into the market and implementing pre-bidding for renewable energy generation, to respond to the variability of renewable energy and ensure stability in power supply and demand management.

First, to visualize the impact of unmetered solar power, the government will integrate dispersed information from KEPCO, the Korea Power Exchange, and the Korea Energy Agency to build infrastructure capable of real-time monitoring and remote control. Additionally, it will consider expanding market participation by lowering the facility capacity threshold for mandatory market participation under the Electricity Business Act (currently over 1MW).

The government will also increase market-participating solar power, which currently accounts for only 28%. By improving generation forecasting capabilities, it aims to enable stable grid operation planning and ultimately incorporate it into the central dispatch generation units. To this end, a "renewable energy bidding system" that allows market bidding by renewable energy operators above a certain scale, centralizes renewable energy dispatch, and assigns the same opportunities and responsibilities as other power sources will be pilot introduced in the Jeju region by the end of this year. The Ministry plans to expand this nationwide based on the pilot project results.

Introduced in October 2021, the "Renewable Energy Generation Forecasting System" will be used as a transitional system for generation forecasting until the renewable energy bidding system is fully established. This system requires submission of forecasted generation for solar, wind, or aggregated power resources of 20MW or more and provides settlement payments based on forecast error rates.

An official from the Ministry said, "Solar power contributes to supply and demand by reducing peak demand (unmetered) and expanding supply (market participation), but its output variability due to weather reduces the predictability of supply and demand. To ensure stability in supply and demand management, system improvements are necessary to incorporate unmetered solar power into the market and strengthen the predictability of renewable energy through pre-bidding."

(Photo)

This content was produced with the assistance of AI translation services.