Ask Lemmy

tl;dr/conclusion: just flush your urine. this post isn't accounting for the increased used of cleaning products caused by urine stains, so really all of these numbers are even lower than they appear. if you actually want to reduce carbon emissions and energy usage, your energy is better spent on political actions. and if you insist on reducing consumption, stop buying avocados and turn off your air conditioning - that's gonna have magnitudes more of an effect than not flushing.

Let's do the math. Average toilet uses about 1.6 gallons (0.00606 m³) of water per flush *ᵃ. Flushing doesn't actually use energy, but it takes energy to both

1) treat the water before it gets to your house and

2) to pump that water to your house

It takes about 1 kWh to treat 1,000 gallons of water (3.785 m³) *ᵇ. That translates to about 0.0016 kWh per 1.6 gallons (0.00606 m³). So it takes 0.0016 kWh in order to treat the amount of water your toilet flushes in a single flush.

It takes about 3,300 kWh to pump 1 million gallons of water (3785 m³) *ᶜ. That translates to about 0.00528 kWh per 1.6 gallons (0.00606 m³). So it takes 0.00528 kWh in order to pump that 1.6 gallons (0.00606 m³) of water per flush.

If we add those two together, we get 0.00688 kWh needed to pump and treat the water every time you flush. Let's try and put that amount of energy into reference.

Microwaves use about 1000 watts (1 kW) when running. Therefore, 0.00528 kWh could run a microwave for about 0.318 minutes (or about 19 seconds)

Computer Desktop: Assuming a desktop consumes around 400 watts, 0.00528 kWh would power it for roughly 0.0132 hours (or about 47 seconds)

Toasting Bread: A toaster might use around 1 kW of power. Therefore, 0.00528 kWh could power a toaster for about 0.32 minutes (around 19 seconds)

So, let's see how much energy we would save if every single household in America flushed one time less per day. There are about 125.7 million households in the US *ᵈ. That would translate to about 864,816 kWh per day, assuming every household flushed exactly once less than they usually do. Let's put that figure into reference.

In 2022 the total US consumption of electricity was 4,271.88 TWh *ᵉ which is about 11.7 billion kWh per day. This means that if everybody flushed one time less (meaning 864,816 kWh less), it would reduce total energy consumption by about 0.0074%.

Bitcoin globally consumes around 150 TWh per year *ᶠ, which translates to approximately 411 million kWh per day. 864,816 kWh represents about 0.21% of the total energy spent on Bitcoin mining per day.

Air conditioning consumes approximately 6% of the energy in the US *ᵍ. Since we know that total US consumption in a year is 4,271.88 TWh, that translates to about 702.23 million kWh per day. 864,816 kWh represents about 0.123% of the total energy spent on A/C per day.

sources

a: https://www.savingwater.org/indoors/toilets/how-much-water-does-your-toilet-use/

b: https://www.esmap.org/sites/default/files/esmap-files/FINAL_EECI-WWU_TR001-12_Resized.pdf--

c: https://css.umich.edu/publications/factsheets/water/us-water-supply-and-distribution-factsheet

d: https://www.census.gov/quickfacts/fact/table/US/HSD410222

e: https://en.wikipedia.org/wiki/Electricity_sector_of_the_United_States#Electricity_consumption

f: https://digiconomist.net/bitcoin-energy-consumption

g: https://www.energy.gov/energysaver/air-conditioning