What is an energy crisis and why does it occur?

1. What is an energy crisis?

2. Why does an energy crisis occur? The four main causes

3. Current energy situation: the 2026 context

4. How can the pressure of an energy crisis be alleviated?

5. Is Spain prepared for an energy crisis?

An energy crisis is a mismatch between the supply and demand of energy resources (oil, natural gas, electricity, or petroleum products) caused by geopolitical conflicts, production failures, or climatic factors. This causes price spikes and threatens the security of supply for households, industries, and entire economies.

Understanding what causes them is the first step in anticipating their impact and evaluating responses.

What is an energy crisis?

An energy crisis is the system's inability to balance energy production with consumption needs at affordable prices.

It affects primary energy (crude oil, natural gas, coal, uranium) and petroleum products (electricity, refined fuels like diesel or kerosene, industrial heat).

The impact varies depending on each country's position in the global energy chain:

• For net importing countries like Spain: a crisis occurs when the demand for primary energy or derived fuels exceeds the available supply on international markets, sending import costs and final consumer prices soaring – from petrol to electricity bills.
• For exporting countries (such as members of OPEC, the Organization of the Petroleum Exporting Countries): it can arise from an oversupply that causes prices to collapse, threatening the viability of their economies, or from signs of accelerated depletion of their reserves.

Why does an energy crisis occur? The four main causes

1. Imbalance between energy supply and demand

This occurs when demand growth, driven by economic expansion, industrialisation, or climate change, is not accompanied by a parallel increase in production.

There is an inevitable structural lag between the decision to invest in a new oil field, power station, or regasification plant, and its entry into commercial operation, which can take between 5 and 10 years.

2. Geopolitical tensions

Much of the world's oil and gas is produced in or transits through geopolitically unstable areas. When a conflict breaks out in a key producing region or a strategic transit route is blocked, millions of barrels can disappear from the market overnight.

3. Raw material shortages and external dependence

Many countries rely on importing the oil, gas, and other raw materials they need. When supply is interrupted, there is no immediate substitute: without gas, there are no fertilisers; without naphtha, there are no plastics; and without critical metals, there is no renewable technology.

4. Climatic and environmental factors

Prolonged droughts that reduce hydroelectric generation, heatwaves that send air conditioning consumption soaring, storms that can damage production or transport infrastructure, or very cold winters that increase heating demand are all factors that can trigger situations of energy stress.

According to the Global Energy Review 2026 by the IEA, in Europe the combination of a cold winter with low availability of hydro and wind power in 2025 drove up the demand for natural gas for electricity generation, even in a context of already high gas prices.

Current energy situation: the 2026 context

The global energy scenario in 2026 is defined by the conflict that began on 28 February 2026, which led to the almost complete closure of the Strait of Hormuz, through which 20% of the world's oil and 20% of its refined products, as well as 18% of liquefied natural gas (LNG), transit.

According to the IEA's April 2026 Oil Market Report, in the first days of April, the volume of oil and fuels crossing the Strait each day dropped to 3.8 million barrels per day, compared to over 20 million barrels per day in February. In other words, it went from channelling 25% of global maritime oil trade to moving less than 4% of global supply.

The impact on global supply was immediate, dropping drastically in March: over 10 million barrels per day stopped reaching the markets. Behind the collapse? Attacks on energy infrastructure in the Middle East and the effective blockade of the Strait of Hormuz. The result? The largest oil supply disruption recorded to date, according to the IEA.

How does an oil shortage impact the wider economy?

Oil is behind almost everything we produce, transport, and consume. Its shortage or price increase cascades through the economy via several channels, which international organisations have accurately documented in the context of 2026.

When oil becomes scarce or expensive, the consequences are felt across the economy: the cost of transporting any good rises, airlines adjust flights and raise fares, plastics and chemical factories reduce production due to lack of raw materials, and food becomes more expensive because producing and distributing it costs more.

According to the IMF, such events drive up prices, destabilise supply chains, reduce household purchasing power, and simultaneously slow economic growth.

Examples of past energy crises

Since its foundation in 1974, the International Energy Agency has intervened on six occasions to stabilise oil markets by releasing emergency reserves from its member countries.

The five interventions prior to 2026 took place in 1991 (Gulf War), 2005 (Hurricane Katrina), 2011 (Libyan Civil War), and twice in 2022, both in response to the Russian invasion of Ukraine. This conflict sent natural gas prices in Europe soaring to record highs, exceeding €300/MWh in August 2022, and forced the EU to implement an emergency 15% reduction in gas consumption.

IEA members hold over 1.2 billion barrels in emergency reserves, alongside a further 600 million barrels under government obligations.