Electricity prices: why they vary and how they affect your bill with a market tariff

You open your electricity bill and the numbers don't add up. You don’t remember consuming more than last month, yet the amount has increased. What happened?

In recent months, electricity prices have continued to fluctuate, raising questions in many households. Unexpected increases, occasional drops, and differences depending on the time of day make it difficult to fully understand what is happening.

How electricity prices are calculated in Spain

The price of electricity in Spain is determined in the wholesale market, also known as the “electricity pool”. Simply put, the price is set based on the supply and demand of energy for each hour of the day.

This means that:

• If there is a large supply of energy and low demand, the price decreases
• If many people and businesses consume electricity at the same time or supply is limited, the price increases

In addition, different generation technologies (renewables, nuclear, hydroelectric, etc.) are part of this process, which influences the final result.

Why electricity prices vary

Electricity prices in Spain are not fixed and change daily, even hourly. These variations are not random but are driven by several key factors:

Renewable energy production

When there is more solar or wind energy generation, prices tend to decrease, as these sources have lower costs.

Level of demand

Electricity consumption is not the same throughout the day. For example, when people return home in the evening and use several appliances at once, demand increases and prices may rise.

International energy market conditions

Electricity prices do not exist in isolation. The availability of natural gas or geopolitical developments also influence the final cost. These factors are beyond the consumer's control, but they have a real impact on the bill.

Seasonality and weather

Factors such as extreme cold or heat can increase consumption. A mild day is very different from a cold spell or a heatwave, when the use of heating or air conditioning rises significantly.

Understanding these factors will not give you control over the market, but it will help you be better prepared and more aware of your energy consumption. And that is where real savings begin.

The cheapest hours for electricity: when it is best to consume

In the current context, there are now more pronounced differences between the cheapest and most expensive hours of the day. In practice, this means that choosing when to consume electricity is more important than ever.

If you have a variable tariff, the timing of your appliance usage matters greatly. The general pattern in Spain is quite consistent:

This behavior is related to consumption patterns and the availability of renewable generation.

In practice, this means that if you have a Nordy Market Tariff, running the washing machine, dishwasher, or charging your electric car at midday or during the early morning can lead to real savings on your monthly bill. There is no need to change your entire routine: simply shifting the moments of highest consumption is enough.

How electricity prices affect your bill

The impact on your bill depends mainly on the type of tariff you have contracted.

Knowing that prices vary is useful, but what really matters is how this affects what you pay. And here, a key factor comes into play: the type of tariff you have.

• If you have a variable tariff, the price you pay per kilowatt-hour (kWh) changes according to the wholesale market price in each time slot. If you consume during cheaper hours, you pay less; if you consume during peak hours, you pay more. This tariff can be convenient if you have the flexibility to adapt your consumption.

• If you have a fixed tariff, the price per kWh remains the same throughout the contract period. The market may rise or fall, but your bill remains predictable based on your consumption. This option offers greater peace of mind, especially if you cannot or do not want to check prices every day.

In both cases, understanding how prices vary allows you to make more efficient decisions about your consumption.

Electricity prices are dynamic and influenced by multiple factors, but understanding how they work allows you to anticipate changes and adapt more effectively.

Which option is better? It depends on your consumption profile and your tolerance for uncertainty. What is certain is that understanding this difference is the first step toward making a decision that fits your actual situation.

Frequently asked questions about electricity prices in Spain

Why does the price of electricity change every day?

Electricity prices depend on the balance between available energy (solar, wind, nuclear, gas) and demand. As both factors constantly change due to weather, consumption habits, and international market conditions, prices also vary daily and even hourly.

What are the cheapest hours to use electricity in Spain?

In general, the central hours of the day (12:00–16:00) and early morning (00:00–08:00) tend to have lower prices due to solar generation and lower demand. Evening hours (18:00–22:00) are usually the most expensive. The exact price varies each day, so it is advisable to check if you want to optimize your consumption.

How can I check today’s electricity prices in Spain?

You can consult hourly prices on our site or at Red Eléctrica de España (REE) website.

Does the price of electricity affect all users equally?

No. The impact depends on the contracted tariff:

• Variable tariff: your bill rises or falls with the market.

• Fixed tariff: the price remains stable during the contract period, regardless of what happens in the wholesale market.

Can I save on my electricity bill by adjusting my consumption?

Yes. If you have a variable tariff, shifting the use of high-consumption appliances (washing machine, dishwasher, oven) to cheaper hours can significantly reduce your bill. It is not about changing your lifestyle, but about making small adjustments during peak consumption periods.

Which factors affecting electricity prices are beyond my control?

External factors such as weather, renewable availability, or fluctuations in international markets are beyond the consumer’s control. What matters is focusing on what you can control: when and how you use energy.

Do you want to know if your current tariff is the most suitable for you? Calculate your potential savings with our team.

Calculate your savings now and contract with Nordy!