You might be among those lucky enough to have more free time on August afternoons. Especially those plan-free afternoons when, forced to choose between a nap and a TV marathon, the series wins out.

With the sofa ready and the living room perfectly cooled, you can lose yourself in GoT, TWD, NCIS, Money Heist, or SWAT. But whichever series you watch, there is one you won't miss: TEB, also known as The Electricity Bill.

Without giving any spoilers, let's give you a sneak peek of what happens in the final episode. Just like in any other story, the tension rises. And the tension, which we prefer to call kWh here, rises too. The important thing is to make sure that, unlike your favourite series, it does so without any surprises.

There's someone else watching the series: your electricity meter

You didn't invite it. Or maybe you did, but you can't remember. The electricity meter is part of the family and, as such, is up to date on everything happening at home. When you turn on the router, it knows. Or when you nod off right at a crucial moment and have to rewind. It also knows if you've turned on the air conditioning, and if you're fixing up something for dinner in the microwave.

The meter knows everything and, like the Targaryens, the Russells, the Professor, Peter, or Catherine, it does its calculations. Calculations that are, fortunately, much simpler than those Eleven needs to fight monsters:

If the episode you are watching lasts an hour and your TV consumes 0.1 kWh in that time, with a price of €0.109/kWh like the Conecta Luz Tariff, the meter will tally up €0.0109. And the same goes for each episode, adding whatever else you are using alongside the TV, such as the router, the air conditioning, or the soundbar.

How much does the TV consume during an afternoon of binge-watching on the sofa?

When you look at the list of the most-watched series, it's clear there's something for everyone's taste. The same goes for televisions. We all have our preferred TV setup at home. And, as a result, every series can have different electricity consumption levels.

As we summarised in the previous section, the cost of an hour of watching TV isn't much. However, if you're seriously dedicating yourself to TV marathons this August, the accumulated cost can become noticeable by the end of the summer.

Therefore, knowing which TV consumes more or less can help you choose the best option, so you can save on electricity without sacrificing image and sound quality:

* Calculation based on Endesa's Conecta Luz Tariff (€0.109/kWh) and an episode duration of one hour.

Winter is still not coming: how much it costs to watch the series with the air conditioning on

The weather forecast says this August will look more like the dragon spin-off than the wintry scenes of the original series. So, in the absence of snow and Jon, you'll need another idea to keep your living room as cold as a Lannister's heart.

That's where air conditioning comes into the picture, emerging as the star of your electricity bill.

Compared to the single cent the TV consumes per episode, cooling a large living room can cost around 30 euro cents* every hour. An amount that, multiplied by the 8 seasons and 73 episodes of that particular game of thrones, will take a much bigger toll on your kingdom's coffers by the time you've finished watching it all, and autumn is drawing near: almost €22, just on air conditioning.

* Calculation based on Endesa's Conecta Luz Tariff (€0.109/kWh), a 3,000 W A/C unit, and an episode duration of one hour.

The supporting cast of your bill: router, soundbar, and snacks

As you might have guessed, without the internet there is no series marathon, and without a router there is no internet. Leaving aside your data and streaming subscriptions, the router consumes a small amount of energy while in use, barely exceeding €0.001 per hour.

The same applies to the soundbar. If you want to enjoy an experience closer to an afternoon at the cinema, the consumption of a separate sound system can add approximately another €0.014 to the experience.

And, speaking of the cinema, you'll probably be planning to make a crispy serving of popcorn in the microwave. If so, you'll have to add an average of €0.004 to the total for those 3 minutes listening to the kernels popping inside the bag.

A cost that rises a bit more if you're hooked on Walter White's series or another one that involves a lot of cooking, because you'll get the urge to get stuck in and turn on the air fryer. This could bump your bill up by around €0.055 per session, using the device for 15 minutes at maximum power.

Comparison table: you decide how much electricity to use per season

Taking all the above into account, it is time to choose how much electricity you want to pay for in your series marathon this summer, for every 10-episode season:

* Calculation based on Endesa's Conecta Luz Tariff (€0.109/kWh), estimated device consumption, 10 episodes per season, and an episode duration of one hour.

Keep your nap separate from your TV time, and other tips to save on your series marathon

If you're someone who dreams of August afternoons so you can take a quiet nap, our top tip is to hold off on turning the TV on. This stops you from multiplying your costs by having to search for and replay the parts you missed. And, even if it's only a little, it's more than dozing through a boring stage of the cycling.

But dreams aside, there are some tricks that really do make an impact on your electricity bill:

Fight the main villain of your energy bill: an overheated house

During the middle of the day, stop the heat from entering the house: closing the windows and blinds considerably reduces air conditioning consumption. Likewise, take the opportunity to ventilate the living room and freshen the air during the cooler moments, like first thing in the morning and, if the series marathon goes on, late at night.

Combine the air conditioning with the use of a fan

Fans consume much less electricity than air conditioning units. If you alternate them, you will be able to maintain a pleasant temperature for longer, with less expense.

Cook between episodes

Having the air conditioning, the TV, the soundbar, and the air fryer or microwave all on at the same time is not a good idea for saving money. As well as pushing the limit of your home's contracted power capacity, you'll be using electricity you aren't enjoying. If you go to the kitchen, take the opportunity to give your living room a rest too.

Fight standby: turn devices off completely

You've seen it a thousand times in your favourite series: leaving things half-finished has consequences. If, when you finish your marathon, you leave your devices on standby instead of switching them off completely, they will continue to consume approximately 10% of the energy they use when running. The easiest thing to do is use switched extension leads or smart plugs, so you can disconnect them all easily.