## Short Post on Short Showers

I finally was able to reduce my flying this year to just two flights to visit family for the holidays. My partner still points out that I take long showers so I should get off my high horse. I've decided to fix that.

#### A little math

I found several calculations of the amount of carbon dioxide produced by a shower. This varies by energy source so I tried a quick calculation for my own residence.

Assuming 2.5 gallons/minute of shower, and that I'm heating the water by about 60 degrees, we can use this equation to calculate the power needed.

2.5 gallon/minute x 8 lbs/gallon x 1 BTU/lbºF x 60ºF =1200 BTU/minute

I heat it using electricity,and it seems that electric water heaters are generally considered to be around 90% efficient. So I'm actually using 1200/0.9 = **1333 BTU/minute**.

California's PG&E power mix says it is only 15% fossil fuel (probably mostly natural gas). According to the US EIA, natural gas releases ~50 kg of CO2 for every million BTU or equivalently 0.05 g/BTU. So at this point it seems every minute of shower is 1333 BTU/minute * 0.15 * 0.05 gCO2/BTU = **9 gCO2/minute**.

For perspective, I used this online flight carbon calculator to calculate that I released 0.29 metric tons of carbon (or 290000 grams) to visit my family in Tuscon this Thanksgiving. So that one trip was equivalent to showering for 22 days straight.

#### Shortening my showers

So showers are a drop in the bucket (pun intended) compared to flights, but I still figured I could make a change. I take about a 12 minute shower every day. I figured I could drop that to 2 minutes if I try. That 10 minutes would save 90 grams of CO2 a day, and if I could keep it up for a year, that'd be about 32kg. That's equivalent to an 80 mile car ride. But no one will ride in the car with me because I'd be smelly.

Anyway, I'll be setting a timer to try to get down to 2 minutes by January 1, and after I'll see if I can go the whole year. Please leave a comment if you see something off in my calculations.

*Update: I forgot that part of the reason for showering was to actually get clean. As it turns out, after a month of showering for 2 minutes I started to get a little gross. So I'm moderating my usage, but no longer limiting to 2 minutes. Oh well, worth it while it lasted.*