What is happening right now

Spain is experiencing its second heatwave of summer 2026. AEMET has issued a special weather warning running from Sunday 5 July to Thursday 9 July, with a blocking ridge maintaining a very dry, warm air mass over much of the country. The worst-affected areas are the Guadalquivir and Tagus valleys, Extremadura, Castilla-La Mancha, and the interior of Andalucía, with maximum temperatures potentially reaching close to 42°C.

Summer turns the electricity market into a lottery

In Spain, electricity prices on the wholesale market can fluctuate several times throughout the day. During the colder months, these fluctuations are usually more moderate, but in summer the situation becomes far more unpredictable.

The combination of extreme heat, increased air conditioning use and solar electricity generation that relies on daylight hours can lead to significant price differences between different time slots during the day.

During the hours of peak solar generation, electricity prices can fall to very low levels. However, towards the evening, just as solar electricity generation drops off while many households continue to use air conditioning, electricity prices tend to rise.

This behaviour particularly affects consumers on the Voluntary Price for Small Consumers (PVPC) or an indexed tariff, as wholesale market prices are passed directly on to their electricity bill.
 

Electricity prices today, 7 July 2026 – hour by hour

Average daily price: €176/MWh · Difference between the lowest and highest price: ×2.5 · Source: REE / OMIE.

With a stable-price tariff, you would have paid the same price at 21:00 as at 14:00 – no surprises, no price spikes. Check out our stable-price tariffs.

Comparison data: June 2025 vs June 2026, day-by-day comparison

Why does extreme heat drive up your electricity bill?

A heatwave can increase your electricity bill because it affects several factors at the same time: it increases electricity demand, reduces solar output towards the end of the day and requires more expensive electricity generation technologies, such as gas, to come into play.

Step 1: Increase in electricity demand

When temperatures exceed 35°C, millions of households and businesses switch on their air conditioning at the same time. This leads to a sharp increase in electricity demand, particularly during the hottest hours of the day.

What's more, during a heatwave, electricity demand does not drop as much overnight, as many homes still need cooling to maintain a comfortable indoor temperature.

Step 2: Solar electricity generation drops off towards the evening

During the midday hours, solar power helps reduce electricity prices because a large amount of electricity generation from renewable sources is available.

However, as evening approaches, solar electricity generation begins to decline. And that's precisely when many households continue to consume electricity to power air conditioning, appliances and other electrical devices.

Step 3: More expensive technologies, such as gas, come into play

When demand remains high and solar electricity generation drops off, the electricity system has to rely on other generation technologies, such as gas-fired power plants.

During these hours, gas-fired generation often sets the marginal electricity price, pushing prices higher and increasing the cost of every kWh consumed.

Step 4: PVPC and indexed tariffs reflect these changes first

If you have a PVPC tariff or an indexed tariff, wholesale market prices are passed through to your bill more directly.

This means that, during a heatwave, using electricity in the evening or later in the day can be considerably more expensive than using it during the midday hours, when solar electricity generation is at its highest.
 

Two peaks in the same summer: 22 June and 7 July 2026 (first and second heatwaves)

Average daily price: €157.2/MWh · Difference between the lowest and highest price: ×6.8. Source: OMIE. €/MWh. Typical estimate.

With a stable-price tariff, you would have paid the same price at 21:00 as at 14:00 – no surprises, no price spikes.

What this means for your electricity bill

In summer, an average Spanish household consumes around 9 kWh per day, but on the hottest days this consumption can increase to 15–18 kWh per day.

The difference is not only how much you consume, but also when you consume it. If a large share of your consumption takes place during the most expensive hours of the day, the impact on your electricity bill can be significantly higher.

That is why consuming electricity at an average price is not the same as consuming it during a price spike, such as the one recorded on 22 June. With a PVPC tariff or an indexed tariff, this difference is passed directly on to your final bill.
 

In a month with two or three heatwaves, a household on a PVPC tariff or an indexed tariff may see a significant increase in its electricity bill compared with an equivalent stable-price tariff.

The difference could range from an additional €25 to €40 per month, especially if a large share of consumption takes place during the highest-priced hours. In these cases, the impact is not only determined by higher electricity consumption, but also by consuming electricity precisely during price peaks.

Stable-price tariff: protection from market fluctuations

A stable-price tariff helps protect your electricity bill from the ups and downs in the wholesale market. Even in the event of a heatwave, changes in gas prices, geopolitical tensions, or disruptions to the electricity system, the price you pay per kWh remains the same for the duration of your contract.

This means you know in advance how much you will pay for every kWh you consume. Your bill may vary depending on whether you use more or less electricity, but it will not depend on hourly spikes in the electricity market.

Summer 2026 has already shown that price spikes are unpredictable

The peak recorded on 22 June and the new peak on 7 July are not isolated events, but rather examples of how the combination of a heatwave, higher electricity demand, reliance on gas generation, and volatile wholesale market prices can directly affect electricity bills. So far this summer, we have already experienced two episodes above €270/MWh, and forecasts do not rule out further spikes before September.

On the hottest days, consumption soars and prices can rise precisely during the hours when more electricity is needed.

With summers becoming increasingly hotter and continued uncertainty in the energy landscape, signing up for a stable-price tariff can help you face the summer with greater peace of mind. This way, you will know in advance how much you will pay for each kWh you use, even during periods of peak demand.

Data sources: Red Eléctrica de España (ESIOS) · OMIE · AEMET · PVPC prices excluding taxes

Update history: 25 June   AEMET alert updated · 23 June  Hour-by-hour peak table · 22 June