How showering is probably a larger part of your CO2 footprint than you think

We need to talk about energy. How we use it and how we can reduce the amount we need every day. What can every single person really do? And where should we start?

In an upcoming series of blog posts, we want to analyze a few ideas of what we can do to save energy in our personal lives. And help you to decide what good measures might be for you. Let’s start with one thing that often is overlooked. Showering. Smells weird? Understandable. So let’s get into it.

Disclaimer

Having said all that, we want to emphasize that no individual action any of us takes will help us to prevent the climate crisis. To do that, we need to implement changes in large, industrial facilities and our energy system. We are also working on that. Don’t worry. Until then, however, we will continue to share measures that help you save money. Nothing more. Nothing less. We hope it helps.

Heating water is expensive

To shower, you need hot water. We are oversimplifying here a bit, but the energy amount that you need for your shower is determined by the following things:

• the amount of water you use
• the temperature of the water

To understand this better, we can do a little example calculation. The amount of water you use depends on how long you shower and how much water you use. The average flow rate of water from showerheads, according to US EPA, is 10l/min (converted from 2.5 gallons/minute ). On average, according to People’s showering habits revealed in survey, people shower for 8 minutes per day. This results in 80l of water per day. This leads to the second factor. On average, the shower temperature lies at 38°C. The amount of energy needed to heat 80l of water from 10°C to this level is approximately 2,6 kWh.

Actually, it’s even worse than that…

If you, like many people in Europe, heat your water using gas, this results in a 20 cent price tag for your shower. Per year, per person, this amounts to 66€.

Until now, we assumed that every energy unit stored in gas can be directly converted into hot water. In reality, however, this is not true. According to heizung.de, a real coefficient of performance is in the area of 46%.

Your annual CO2 footprint due to showering, consequently, is ~1010 kg.

As EU, showering makes 10x the amount of what we need for lighting

There are 447 Million people in the EU. If they all behave like an average person (8 minutes, daily shower), the total energy demand to heat our shower water amounts to 913 TWh or 4,5% of the EU’s energy demand. For comparison, this is almost 12x the amount of energy we use for aviation.

We can reduce our individual energy demand by changing the way we shower

Playing around with the numbers above, you can now estimate how much your actions would help. Here are some examples that you might consider!

• Reducing your shower time: every minute saves 260 kWh, or 18€ per year
• Lower your shower temperature: every degree cooler saves ~100 kWh, or 7€ per year
• Shower less often: if you skip every third shower, you would save ~600 kWh, or 42€ per year

In reality, you might do a mix of the above. This should just give you an idea.

With nista.io, we try to make calculations like these easy. If you, many others, would like to give it a try, make sure to register here!