Energy saving tips


1. Use your microwave more and your electric oven less 

How many kilowatts does the consumer pay to use the microwave for an hour? What about if the oven is used?

The advantage of the microwave is that it spends less time doing the same function as the electric oven, e.g. to heat food, we only need 2 to 3 minutes in the microwave while in the oven we spend about 15 minutes. If we compare the consumption of the two appliances for the same period of time, the microwave can consume more, since the oven is not always on.

By comparing a 22 litres oven with a microwave, if both run for 1 hour, the microwave will spend 0,34 cents and the oven 0,18 cents.

The oven will heat up until it reaches the right temperature and then it will switch off. As soon as the temperature inside the oven decreases, it will switch on again. For 1 hour of working the resistances of the oven could be working only between 30 to 45 minutes.

Beware that these estimates may vary according to the capacity of the oven, whether it is ventilated, if it has a thermal blanket, with the kind of supply it has inside and the times we open the door of the appliance.

1.2 Cooking a pre-cooked frozen lasagna
The benefit of the microwave is in the fact that its technology allows cooking food more quickly. For example, a frozen lasagna takes about 7 minutes to cook in the microwave, whereas in the oven it will take 30 minutes. It means that if we cook it in the microwave, its cost will be 3 to 4 cents and if we cook it in the oven it could be 8 to 12 cents (depending on the above analysed factors)

1.3 Heating up food in the microwave
Due to its technology, the microwave is faster heating up food. For example, if you have frozen food or if you only need to heat food, the microwave will be more beneficial. On average, a microwave will take 2 minutes to heat food. An oven will take about 15 minutes (it will have to be pre-heated and only then it will start heating up food). In this case, the cost of heating up in the microwave will be 1 cent, whereas in the oven it will be around 4 to 6 cents.

2. Oven and microwave displays

If your microwave has a display, unplug it, when it is not being used. The consumption of the display can be higher than 7 euros yearly. The same is true for the oven, the saving values being similar; however, it may be more difficult to switch off this appliance from the plug, because of its characteristics, to the detriment of the microwave.

3. Beware of the exhaust fan 

The exhaust fan lamps are often hidden and in older exhaust fans they are still incandescent. This kind of lamp may take up to 45 cents yearly, but if we switch it off the cost will be almost 10 times less (5 cents yearly). Estimate for someone who uses the exhaust fan for 1 hour 3 times weekly.

4. Choose an efficient fridge

The fridge can depict a cost of around 170 euros annually. By choosing a more efficient model, this value can decrease to 50 to 70 euros yearly, which might result in a 100 euros/yearly saving.

5. Do not wash the dishes by hand [AQUA+]

How much does it cost the consumer to wash the dishes by hand versus how much does it cost to use the dishwasher? How much can the consumer save if he/she stops washing the dishes by hand?

The purchase of an efficient dishwasher can result in savings of about 16 thousand litres yearly, which represent savings of 19 euros in the annual water bill.
A more efficient model can generate savings of up to 41% of water consumption, when compared to less efficient appliances.
In choosing, you should take into consideration, the water consumption, visible in the energy label:

- Always look for the most energetically efficient appliances (energy classes of A up to A+++).
- To reduce the water consumption, apart from the energy class, look for dishwashers whose label will indicate a lower average annual water bill (lower than 2.500 L/year for dishwashers).

In another hand, the dishwasher is one of the most energy consuming appliances in the kitchen and 90% of that consumption corresponds to the water heating cycles for washing the dishes and of air for drying.

By replacing your older dishwasher by one more efficient, class A, you can decrease your energy bill in 35 euros.


6. Charging your mobile phone overnight?

How many kilowatts does it cost to the consumer to charge the mobile phone for an hour? What is the difference between charging at night or during the daylight?
In euros, how much does it cost in the energy bill to charge your mobile phone during an hour at night versus during the day?

To charge your mobile phone at night or during the day will only have an economic difference if you have bi-hourly tariff. The energy consumption to charge the phone will depend on the fact if it’s on while you charge it, the model, the software, and the charger, among others. To charge the phone can cost between 80 cents and 2 euros per year. In case you have bi-hourly tariff, and if you charge it at night, when the cost of energy is cheaper, this value can decrease to 40 cents to 1 euro.

7. If you switch off or adjust the air conditioner temperature an hour before you go to bed you can save energy

How many kilowatts does it cost to the consumer to have the air conditioner on during an hour at night?

Air conditioner is a highly efficient appliance. It consumes up to 3 to 4 times less energy than a radiator or ventilator. Air conditioning can consume between 15 a 30 cents/hourly, depending on the outsider temperature, the size of the air conditioner and its efficiency. If you switch it off 1 hour earlier, this will be the sum you could save. 

8. How much can the consumer save if he/she switches off the air conditioner temperature before going to bed?

You should keep the temperature to 18ºC in the winter and 25ºC in the summer. The change of 1ºC in the temperature represents a 7% saving in the consumption of this appliance.

- In the summer: instead of putting on the air conditioner to 22ºC, put in on to 25ºC, and you can save 21% of the consumption.
- In the winter: instead of putting it on at 21ºC, put in on at 18ºC, and you can save up to about 21%.

9. Air conditioner vs electric heater

The electric heater spends around 3 to 4 times more than the air conditioner. If you switch on your electrical heater for 2 hours for 2 months, the cost will be higher than 150 euros. If you do it with an air conditioner, the cost might not reach 60 euros. These values will vary according to the outside temperature and with the efficiency of both appliances, among others. 

10. Using intelligent lamps

How much does it cost the consumer using regular lamps versus intelligent lamps? How much can the consumer save by using intelligent lamps?

Intelligent lamps can be convenient given that they can be set at a distance, reduce the intensity or even change the light colour. However, as they are controlled through Wi-Fi, they have an associated consumption of 0,5, which is translated in an added cost of 1 euro per year, per lamp.

11. Changing everything to LED. Associated saving per lamp

Do you still have fluorescent lamps? Consider changing everything to LED. If you have a lamp with 5 fluorescent lamps of 8 W and 2 more in your night table, by replacing them for led the annual cost decreases from 4,5 euros to 2,25 euros (assuming they will be on for 1 hour for 365 days per year).

12. Unplugging the TV 

Do you know what is that little red light in the bottom part of your TV set? It means the appliance is in standby mode (waiting mode). This light may represent a 5 euros cost/yearly in your energy bill. Switch off the TV from the plug, whenever it is not being used.


13. Closing the tap while brushing your teeth

How much does it cost the consumer if he/she doesn’t close the tap while brushing the teeth versus what the water bill will be if he/she closes the tap? How much can one save?
Closing the tap when the water is not being used is a good practice in every situation!

Considering that a conventional lavatory tap has a flow of at least 6 L/min and that we take about 2 min to brush our teeth twice a day, we will be wasting 24 L/day in brushing our teeth only.
More important than the changing in behaviour, it will be intervening at the level of the tap in itself. The replacement of the conventional lavatory tap for an efficient tap results in savings of about 43 thousand litres, which represent savings of 50 euros in the annual water bill.
To choose the most efficient devices one should purchase items with hydric certification of products of ANQIP, whose labels will help to choose the most efficient ones in the combination between functionalities and flow.

14. Installing an efficient shower

Just like the lamps, how much does it cost the consumer using a regular shower versus an efficient shower? How much can a consumer save by using an intelligent shower?

The replacement of conventional showers by efficient showers, results in savings of about 43 thousand litres of water yearly, corresponding to a yearly decrease of 50 euros in the annual water bill. This investment has a payback period of 1 year. Even for a region with a very low average water price (eg. 0,15 €/m3), the payback period is of only 4 years.

Considering that the consumed water is heated water, it also results in an associated energy saving, that can be around 150 euros annually if it is a gas heater, and 300 euros yearly if it is an electric water heater. Note: these values depend on how far the bathroom is from the shower or water heater, of the efficiency of the current shower, the amount of baths, among others.

To choose the most efficient devices one should purchase items with hydric certification of products of ANQIP, whose labels will help to choose the most efficient ones in the combination between functionalities and flow.

Living room

15. Control the temperature of the heater and do not block it with the furniture

How many kilowatts does the heater on cost to the consumer if it has a higher temperature? And much does it cost if it has a lower temperature?

In euros, how much does it cost in the energy bill using the radiator with a lower temperature versus a higher temperature?

In general, radiators have the potency they can be used instead of the temperature. Typically, if we switch on one button we will use 1000 W. If we press both, we use 2000 W. If we use this appliance 3 hours a day for 3 winter months, it will have an added cost in your bill of about 120 euros if you use full power and of 60 euros if you use only half.

16. What is the difference between a fan heater and air conditioning

By using the heater in full power for 3 hours daily for 3 months, you will have a cost of 120 euros annually. If you opt for air conditioning, your cost will be of 43 euros. Air conditioning is far more efficient than an oil radiator or a fan heater.

17. Forget standby mode

How many kilowatts does it cost to the consumer the standby mode and why is it important not having the appliances in that mode? How much does it cost if you leave it in that way? That is, how much does it cost in the energy bill the use of the standby mode versus non-usage? 

This value depends a lot of the quantity and efficiency of the electrical appliances, however these are the estimated annual costs:

- Television + box: 6,8 euros 
- Router: 19,3 euros (this value is not in standby mode), but with the router switched on. That is, if you’re working from home you can not switch it off. But if you leave home and go to work and you do not switch it off, you will have an added increase of 19,3 euros.
- Playstation: 2,2 euros
- Sound system: 13,5 euros
Total cost in the living room only: 41,79 euros /ano.

18. Use intelligent plugs 

How many kilowatts does it cost the consumer using regular plugs versus intelligent plugs? How much can the consumer save by using intelligent plugs?

Intelligent plugs offer more convenience, but they have the same effect as unplugging manually or through plugs/extensions with buttons. And there is the associated consumption of the power plug itself. Each plug has in average a power of 1,2 W, which represents a cost at the end of the year of 2,3 euros. If you have 4 outlets, this cost might increase to 9 euros annually. Therefore, the best thing to do is switching on all appliances to an extension with a button and switch off that button when no longer using the appliances.

19. Use LED lamps in the living room

Consider replacing the lighting in your living room for LED. Assuming a living room with 8 fluorescent lamps of 13 W which are switched on 2 hours a day, you will have an annual consumption of 6,7 euros. If we replace them for LED with a potency of 6W, the annual cost will be of about 8 eur.


20. Avoid printing

The most efficient offices do not print? Is that true? Why? Does printing have to cost?

Offices do not print in order to waste less paper and, consequently decrease the felling of trees. Anyway, printing in a house printer will have an average cost of 2 to 3 euros for each 100 pages.

21. Turn off all electrically connected electronic devices

Do appliances connected to currents, but not being used, cost how much to the consumer? And when would you be able to save, in euros, if you no longer have them connected to the plug.

Imagine computers that are no longer charging, cell phones, televisions… Always unplug your computer, monitor and printer from the electrical outlet. Even though they are not turned on, they continue to consume energy. These costs represent 2.38 euros per year.

22. If you have a monitor, consider reducing its brightness

Some monitors have the brightness set to maximum. You can reduce its brightness and consequently its consumption. In some cases it even improves eye comfort. With this reduction you can save about 4 euros per year.


23. Water the garden with automatic irrigation systems

How much does it cost the consumer to use normal irrigation systems versus automatic irrigation systems? When can the consumer save when using automatic irrigation systems?
The use of efficient irrigation systems, namely, drip or micro-sprinkler systems with automatic activation by humidity sensors or a timer, allows watering with the amount of water strictly necessary and at the appropriate time, without waste inherent to the use of a hose attached to a conventional faucet.

24. Use solar powered lamps

What costs does the use of normal lamps have for the user versus what costs do these powered by solar energy cost? How much money can the consumer save at the end of the day? By replacing a lamp with a power of 5W that would be on for 4 hours a day, with a lamp powered by solar energy, you can save about 1.6 euros per year. If you have 10 lamps, you can save 16 euros a year.


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