LISBON, Aug. 10 (Xinhua) -- A near-total solar eclipse passing over Portugal on Aug. 12 is expected to reduce the country's solar power generation by an estimated 45 percent during the eclipse, grid operator REN announced Monday, as national and European grid operators prepare contingency measures.
The eclipse, which will reach magnitudes of 92-100 percent across mainland Portugal with greatest intensity in the north, will occur between 18:30 and 20:30 local time and is expected to cause a loss of approximately 450 megawatts of solar generation, equivalent to around 7 percent of total national electricity consumption at that hour.
At peak impact, solar output is expected to fall at a rate of up to 35 megawatts per minute, requiring the mobilization of additional hydroelectric and thermal reserves to maintain balance between generation and consumption and control deviations in the interconnection with Spain.
REN noted that the impact will be partially limited by the timing of the eclipse, which occurs in the late afternoon when solar production is already declining naturally and demand is transitioning toward the evening peak.
Preparations are being coordinated with European transmission system operators through the Short Term Adequacy service, which ensures generation-consumption balance over a seven-day horizon.
According to REN, across the European synchronous area, the eclipse is expected to cause a combined loss of approximately 9,700 megawatts of solar output.
Solar energy supplied 19 percent of Portugal's electricity consumption in July, the first month in which solar was the dominant renewable source in the national grid. ■