Knowing how much each appliance consumes and which recipes justify their use can make a real difference to your bill. For example, if your electric oven uses around 1.5 kWh and you are on the Luz Fija 24h Online Tariff at a cost of €0.113500/kWh (including a 20% discount), you would pay around €0.17 for every hour of use. Meanwhile, a microwave typically uses between 60% and 70% less energy, and induction hobs tend to be up to 40% more efficient than traditional ceramic hobs.

How to measure the real cost of cooking (and why just looking at wattage isn't enough)

We often make the mistake of thinking that the appliance with the highest wattage uses the most energy. However, electricity consumption depends on both the volume of energy and the amount of time it is used. While an oven has a power rating of around 1,500 W, it is only used occasionally. A fridge only uses between 200 W and 400 W, but it runs 24 hours a day.

To calculate how much each appliance in your kitchen consumes, use this formula:

kW (wattage divided by 1,000) × hours of use = kWh consumed

It is this kWh consumption that determines the final cost on your bill. Therefore, to use less electricity when cooking, efficiency depends not only on the appliance itself, but on how long it needs to be switched on to get the job done.

The electric oven: the most powerful, but not always the most expensive

Let's return to the earlier example. If your oven is around 1,500 W, its consumption will be 1.5 kWh. If you use an oven for a couple of hours a week, consumption comes to about 156 kWh per year. On the other hand, a 200 W fridge running 24/7, despite having a much lower power rating, would consume around 1,752 kWh per year. That is where the difference lies.

The oven will only be expensive if you don't use it efficiently, which is why it is essential to know how to use your oven while consuming less energy. Key tips include:

• Do not open the door while cooking to avoid losing heat.
• Cook several dishes at the same time to make the most of the energy used.
• Make the most of residual heat by turning the oven off a few minutes before the food is fully cooked.
• Bake food in smaller portions to reduce cooking times.

The microwave: the option that almost always wins on efficiency

The microwave is a great ally for anyone looking to use less electricity when cooking. According to the IDAE (Institute for the Diversification and Saving of Energy), it consumes even less than a conventional cooker. For certain dishes, these savings can reach up to 75%. Its power usually ranges between 900 W and 1,500 W, but its speed makes up for any high figures, meaning it can deliver real savings compared to the oven.

Despite its efficiency, it has limitations. It is not suitable for complex baking, nor can it achieve crispy textures. However, it is the undisputed king of reheating, steaming vegetables, and defrosting. An expert tip is to cut food into smaller pieces to speed up the process and turn it off a few minutes early so the internal heat finishes the cooking.

The air fryer: all hype and no substance?

The air fryer has become popular as a convection 'mini oven' that circulates hot air quickly and evenly. Its power usually sits between 1,000 W and 1,800 W. The main advantage is that, because it is a small space, it cooks much faster than a large oven and requires hardly any preheating.

The question is: how much energy does an air fryer actually use? Data shows that, with 15 minutes of daily use and a power rating of 1,000 W, its annual consumption would be just 90 kWh. This makes it the best option for foods that require a crispy texture (chips, chicken, croquettes). However, for large quantities, a conventional oven is still necessary.

Ceramic vs. induction hobs: the difference you will notice most on your bill

If we compare induction vs. ceramic hobs, induction is the clear winner. By heating the pan directly using magnetic fields, there is no heat loss on the surface of the hob. This means induction can be up to 40% more efficient than ceramic hobs and cooks almost twice as fast.

Meanwhile, ceramic hobs use electrical heating elements and take longer to reach the optimal temperature. Their only advantage is that they allow you to use any type of cookware (such as clay or copper), whereas induction requires specific pots and pans. When weighing up the differences between induction and ceramic hobs, it is worth noting that induction is much safer, as the hob itself does not get hot.

Comparison table: estimated cost by dish type and appliance

This table shows approximate consumption and the estimated running cost depending on the appliance chosen. The data is based on the standard consumption of each system, a hypothetical average cooking time, and the price of our Luz Fija 24h Online tariff at a cost of €0.113500/kWh (including a 20% discount).

Note: The texture of food cooked in a microwave and air fryer may vary compared to a traditional oven.

Looking at the data in the table, we can see that for everyday tasks, such as reheating or cooking vegetables, the microwave is unbeatable. For meat dishes, the air fryer reduces costs compared to the oven thanks to its speed. However, the oven remains an attractive option when we want to cook in large batches. The key is to understand that savings don't just come from the appliance itself, but from avoiding waste.

4 kitchen habits that reduce costs without changing a single appliance

You don't always need to invest in new equipment; sometimes it is enough to change how you use it.

1. Make the most of residual heat: turn the oven or hob off a few minutes before the food is fully cooked. The accumulated energy is enough to finish cooking the dish for free.
2. Always cover your pots: this reduces boiling time and retains heat much better, especially on ceramic and induction hobs.
3. Don't preheat by default: unless you are baking delicate pastries, for long roasts you can put the food in right from the start and save on that initial consumption. Look for oven recipes that minimise electricity usage to learn specific techniques.
4. Use the microwave to defrost: it is far more efficient than using the oven or hot water.

Furthermore, remember to keep an eye on the standby consumption of your kitchen appliances, which can account for up to 6.6% of your household's total energy costs. Ultimately, knowing which kitchen appliance consumes the most in your home will help you prioritise your energy-saving efforts.

FAQ

Is it worth buying an air fryer just to save electricity?

An air fryer is cost-effective if used to replace the oven for small dishes. If you already have an efficient oven and cook for a lot of people, the investment will take longer to pay for itself.

How much does it cost to use an electric oven for 1 hour?

With the Luz Fija 24h Online tariff (cost: €0.113500/kWh including discount), it would cost you around €0.17 for a 1,500 W oven. If you have a time-of-use tariff, use the oven during off-peak hours to pay less, such as at weekends or in the early hours of the morning (from 00:00 to 08:00).

Which uses less energy: a microwave or an air fryer?

For reheating, the microwave is the absolute winner due to its speed. For cooking from raw when a crispy finish is required, the air fryer is more efficient than a conventional oven because it reduces cooking times.

Does induction really use less energy than a ceramic hob?

Yes, the difference is real and noticeable. By avoiding heat loss through dispersion on the hob surface, induction saves up to 40% of energy and is much faster. It is undoubtedly the key step towards an efficient kitchen.