During the eclipse, what happens to solar power generation?

On 12 August, the Moon will pass between the Earth and the Sun. IGNIS Head of Asset Management, Íñigo Díaz, explains how this phenomenon affects photovoltaic generation and the power system

On Wednesday, 12 August, the Moon will once again pass between the Earth and the Sun, creating a rare astronomical event. Beyond its scientific significance, the eclipse will also have a temporary impact on solar power generation.

As explained by IGNIS Head of Asset Management, Íñigo Díaz, «an eclipse temporarily reduces the solar radiation reaching photovoltaic panels, which in turn lowers their electricity production.» However, this reduction in output will not interrupt the operation of solar plants.

From an operational perspective, solar plants will behave much as they do when a large cloud passes overhead. The key difference is that, in this case, the event can be predicted with complete accuracy. «This is an entirely expected event. Because it is fully predictable, the power system can prepare in advance and schedule the resources needed to maintain a normal and reliable electricity supply,» says Díaz.

When the Moon obscures the Sun, equipment, control systems and operation centres will continue to function as normal. Thanks to advanced monitoring and forecasting tools, operations teams can accurately anticipate production throughout the day and coordinate their response with the other participants in the electricity system.

During an event of this nature, the transmission system operator will maintain the balance between electricity generation and demand from households, businesses and industry. The temporary reduction in solar generation will be offset by other generation technologies, ensuring uninterrupted electricity supply at all times.

Although there may be minor changes in the mix of technologies generating electricity, as well as occasional fluctuations in wholesale electricity prices, an eclipse does not pose a risk to the security or reliability of the power system.

A demonstration of the power system’s maturity

Beyond its short-term impact, an eclipse highlights how much the electricity system has evolved in recent decades. Not long ago, solar energy represented only a small share of the energy mix, and events such as eclipses had little effect on overall electricity generation.

Today, with solar photovoltaic power playing an increasingly important role, eclipses have become an opportunity to demonstrate how a power system with a growing share of renewable energy can continue operating smoothly thanks to careful planning, flexibility and the complementary nature of different generation technologies.

«Eclipses provide a very interesting demonstration of the maturity the electricity system has reached. They also highlight the importance of planning and flexibility. A modern power system combines different technologies that complement one another to guarantee a secure electricity supply under any circumstances,» concludes the IGNIS Head of Asset Management.

IGNIS develops multi-technology energy projects worldwide, holding a leading position in the development of renewable energy, battery storage, grid access solutions, and decarbonisation and electrification projects. At a time when the growing availability of low-cost renewable energy calls for greater system flexibility and supports the electrification of new sources of demand, the company delivers solutions that integrate generation, storage, the grid and demand to maximise the value of the energy transition. IGNIS currently has more than 1 GW of owned generation capacity in operation and under construction.

In addition, the company combines these capabilities with advanced energy and asset management to deliver integrated solutions tailored to its customers’ needs. IGNIS manages 10 GW of owned and third-party assets across all technologies—including renewable, hydroelectric, thermal generation and even the first battery operated by an independent market participant in Spain—while participating in every segment of the electricity market.