Power Consumption of a Shower: 20 KW

Actually, using your assumptions (which sound pretty reasonable) I get 336 W, not 20,000. Still higher than I expected, but not as shocking:

P = (4.2 J/gC) * (40 - 10 C) * (160 g/min) = 20160 J/min
= 20160 J/min * (1 min / 60 sec) = 336 W

You forgot that Watts = Joules/second, not Joules/min.

 

Wow. Yeah, you are right. That is pretty outrageous. I do like my hot showers, though.... Good thing natural gas is cheap.

 

When I was in nepal, and found out they killed a slow growing tree for my shower at a tea house, I stopped showering until I got back to Katmandu.

You can get a good idea of how much energy your hot water is using by looking at your gas bills in the summer. Its not all that much when its plentiful natural gas. At least mine isn't that much.

 

That is an amazing, surprising number for me. Looks right though.

I prefer to think of it in terms of therms , 40 kwh = 1.36 therms, so allowing for gas water heater inefficiency and line losses, about 2 therms a week, or 1 therm per hour of shower time which is about $1.00/hour.

There are also 1.6 gallon/minute shower heads that feel good. If you are using electricity to heat your water, definitely worth considering. Check reviews first though, many of the low flow heads aren't very good.

 

Was that in February of 2009? I made a brief stop at the Katmandu airport on my way from Bhutan to New Delhi and smelled something funny there.

 

I think of it this way, 40kwh is about how much oil is needed to get your prius to go 50 miles. I'm not sure about exact figures, but it doesn't seem like that is all that much energy given that it is domestic and mostly burns to co2 and water. I'm more worried about the imported oil I put in my tank, but hey that's why we bought prii. In terms of money, think of how much more your cell phone costs a day than the hot water in your home.

 

No I was there earlier. Hiked up to Everest base camp from low levels. Once you get near the tree line, you don't really stink that much but everything grows slower. It is kind of strange realizing that things are brought up the mountains with human power. Energy is more valuable when you need to carry your fuel

 

My cell phone costs $10/30 = 33 cents a day, but I'm not the average cell phone user. Now that you mention it, that is approaching our summer natural gas usage cost.

 

My cell phone costs $29 every 2-3 months! $29 prepaid card gives me 360 minutes iirc.

My hot water costs almost nothing,,solar heated, with a small parasytic power cost, with demand gas fired heater if it is not hot enough.

Icarus

 

Sorry, I don't remember what model I had, that was in a house we had 15 years ago. The water company in San Jose gave them away during a water shortage. They were small, solid brass with chrome plated finish and mixed air with the water. I checked the flow with a stopwatch and bucket, it was close to it's rated 1.6 gpm. I think your best bet is to read reviews.

The one I had also had an on-off control on the shower head.

 

Seems like the power consumption can be WAY higher. For instance, CA gets a bunch of its water via diverting Colorado River water (and/or other far away sources). I can't believe 20-30 gallons can come hundreds of mile (pumping up a bunch of mountains and sliding back down) in some cases, and THEN add the heat, can be done for such a low figure. I'm sure many get there water pumped from shorter distances, but it's a factor worth considering.

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Definitely with our drought last year, and the aquifer and rivers not recovered, the water is more valuable than the natural gas. I wasn't saying the showers were fine for the environment, but compared to much of what we waste the natural gas to get us hot showers are not high on the list.

Water and natural gas do come together in many places though. Often fracking is wasteful in water.

 

Note, that is much more expensive than my natural gas. It was $8.14 last month, for two of us. That includes the natural gas for my gas cloths dryer and stove, not just the showers and hot water for washing.


Water and Sewage was 24.49, that water and water treatment are much more valuable than the energy to heat the shower down here.