In the last week of April, the Iberian Peninsula was hit by a massive power outage that crippled Spain, Portugal and parts of France. The blackout lasted for over 36 hours, paralysing transport, healthcare, industry and the normal functioning of households. The economic damage amounted to billions of euros and the event sparked a strong wave of debate about the security of power systems at a time of rapid transition to renewables. The event showed how fragile energy stability can be even in technically advanced countries and became a warning to the rest of Europe.

Although some media initially pointed to renewables as the culprit, a more detailed investigation showed that the cause was not the presence of solar and wind power plants per se, but inadequate infrastructure and the inability of the grid to cope with rapid changes in production. In particular, there was a sudden drop in the output of solar power plants and the grid was subsequently unable to stabilise due to the lack of inertia provided in the past by conventional sources such as coal or gas-fired power plants. The problem was not with renewables, but with the transmission system not being able to respond to the rapid changes in the energy mix.

The effects of such blackouts are not just short-term. In addition to the immediate losses, when production stops, logistics are crippled and services are reduced, consumer and investor confidence suffers. Companies have to consider costly back-up solutions, which increases operating costs and reduces competitiveness. The general public may then face reduced access to basic services such as water, heat or internet. In the context of today's digitalisation, power outages are not only an inconvenience but also a major security and economic risk.

While the Czech Republic avoided the direct impact of the Spanish blackout, it is not immune to a similar scenario. Renewables are also growing in this country, while coal is planned to be rapidly phased out and nuclear sources are due for modernisation. Unless the grid is sufficiently flexible, resilient and equipped with technologies such as battery storage and smart control systems, a similar blackout could spread to central Europe. The events in the Iberian Peninsula should therefore be an impetus for the Czech government and the energy sector to invest urgently in modernising the transmission grid and ensuring stability for the future.