Why do power outages occur?

BarcelonaPower outages are a phenomenon that occurs for various reasons, but a widespread power outage like the one this Monday, which practically affected the entire Iberian Peninsula, is unusual. More or less widespread blackouts have occurred in the past, such as the one that occurred in July 2021, which affected several regions in Spain—including Catalonia—when there was a fault in a 400,000-volt very high-voltage line belonging to Red Eléctrica, or a few years ago, in July 2007, when thousands of customers were left without power, some for up to four days.

Apparently, this Monday's massive power outage was caused by a sharp fluctuation in the load power flow. According to some sources, power supply fell by as much as 11,000 MW, falling from 26,695 to 15,970 MW. How could this happen?

Currently, a stable electricity supply is considered a fundamental pillar for the functioning of any modern society. However, on several occasions, countries like Spain have experienced blackouts that leave millions of families and businesses without power. These events, although occasional, raise concerns about the possibility of a large-scale blackout, known as a major blackout or major blackout. blackoutOne of the weaknesses of the Iberian Peninsula's electrical system is that, until very recently, it was an energy island, and currently its connection to the European system is still very minimal, through the high-voltage power line (HVPL) that crosses the Pyrenees through Catalonia.

In fact, an industry source explained to ARA that at the time of the blackout, Portugal was producing little and, therefore, it is unlikely to be able to transfer electricity to Spain. Furthermore, Spain's interconnection with France is minimal, which will further delay the return of supply, as power plants must be gradually connected to the grid.

One of the most common causes of blackouts is power grid failures and voltage drops. Damage to transmission lines, substations, or distribution components can interrupt the flow of electricity. These failures can be caused by adverse weather conditions, accidents, or even human action. Electrical infrastructure, being complex, requires constant maintenance to avoid failures that could lead to prolonged outages.

Another important cause is overloads. When energy demand exceeds grid capacity, protection systems activate temporary outages to prevent further damage to facilities. This usually occurs during periods of high consumption, such as winter, when temperatures drop and heating use increases. Efficient demand management is crucial to preventing these scenarios.

Extreme weather conditions also play a decisive role in the fragility of the electrical system. Storms, hurricanes, and earthquakes can damage infrastructure and leave large areas without power. In Spain, although the seismic risk is not high, meteorological phenomena such as storms or heavy snowfall can affect power lines and generating plants and cause temporary blackouts.

Cyberattacks

On the other hand, cyberattacks are an increasingly present threat. In recent years, incidents have been reported in various countries where hackers They managed to manipulate or damage critical systems and cause massive power outages. The dependence on digital systems and connectivity makes the security of the electrical grid a priority to avoid crisis scenarios.

Economic consequences

A blackout can have devastating consequences for daily life and the economy. The interruption of essential services such as hospitals, water systems, transportation, and communications can jeopardize the safety of the population. Furthermore, the paralysis of industries and businesses generates considerable economic losses and affects social and economic recovery.

In the current context, concern about a possible major blackout has increased. Dependence on renewable energy (60% of production in Spain), the reduction of nuclear plants, and international conflicts contribute to a scenario of uncertainty. Although Spain has a diversified and robust system, with a variety of supply sources such as nuclear, combined cycle, hydroelectric, and renewable energy, vulnerability to external factors remains a reality that must be monitored.

How the Spanish electricity system works

The Spanish electricity system operates through four main phases: generation, transmission, distribution, and marketing. These phases include additional costs such as contracted power, regulated costs, and taxes.

1. Generation

Electricity is produced in power plants using a variety of sources, including renewable (wind, solar, hydro) and non-renewable (nuclear, combined cycle, coal).

2. Transportation

The generated energy is transported through high-voltage lines (up to 400,000 volts) managed by Red Eléctrica de España (REE) to ensure an efficient and secure supply.

3. Distribution

Electricity is distributed to consumers through general distribution networks (GDGs) from high-voltage substations to urban areas.

4. Marketing

Retailers purchase energy on the wholesale market and sell it to end consumers, including additional costs that determine the final price of electricity.