The Green Economics of Tankless Water Heaters

In theory, a tankless water heater seems like a no-brainer. Why heat your water all day when you're not using it? Providing on-demand hot water is much more energy-efficient. It's the dominant water heating technology in Europe and Asia. Plus it saves tons of space in your home previously occupied by an enormous water holding tank.

With all of this in mind, I started to look into tankless hot water heaters as a possibility in my home. Unfortunately, the economics are incredibly unfavorable.

The total cost of a tankless hot water heater is about $1521. Here's how it breaks down:

• Bosch Aquastar unit: $671. Cheaper and more expensive models exist, but this is one of the most widely-used models.
• Installation: $1000. Installation estimates online varied wildly, but seemed to range from about $500-$2000. I picked a median estimate.
• Energy Company Rebate: $150. To offset the cost some, PSE offers a $150 rebate for tankless water heaters.

I use about $7 of natural gas on water heating per month. The EPA estimates that the tankless water heater will increase my water heating efficiency by about 40%. That's $2.80 saved on my monthly water heating bill.

If you calculate that out, it would take 45 years for the tankless water heater to pay back that money. The projected life of the unit is only 20 years. I'm out about $849 by the time it stops working.

It's simply not worth it. Not when I can buy a 30% more efficient tank heater for a fourth of the cost. This is one green project that sadly, I will not be implementing.

Comments

[Adrian]

Hey just stopping by to get my dose of green info. Always good stuff here! I am trying to compile a list of stuff I can do to reduce my carbon emissions. MTV had a commercial about it, and got me interested. I have been to www.earthlab.com and they have a ton of tips but I was mostly impressed by their page where they have their users send in tips: http://www.earthlab.com/life/tips.aspx Does anyone else know of other data bases that I can find these types of small things that lower my emissions? EPA or WWF maybe?

Thanks for all your info and drop me a link if you guys see anything worth my time.

[schallb]

this system would work good with solar heat to pay for the bill

[plumber glendora]

With all of this in mind, I started to look into tankless hot water heaters as a possibility in my home,i will do the same way thank for sharing.

by: jb