DIY Solar Water Heater

A DIY solar water heater is a popular thing for a number of reasons:

  1. Passive solar water heaters are relatively easy to install
  2. Installing the solar water heater yourself decreases the cost of the system and improves the project economics
  3. There are relatively few plumbers who know how to install solar water heaters

That said, there have been some articles posted online regarding this subject, from “how to build a DIY solar water heater from scratch” to “why solar water heating is dead.” We would argue that the true answer lies somewhere in the middle.

Solar water heating has been around for a long time and has been attacked by fossil fuel and solar panel (herein referred to as solar PV or ‘PV” to differentiate from solar thermal or ‘thermal’) enthusiasts, alike. So here’s our opinion:

Solar Water Heating is Not Dead

Why would it be? The argument is that solar PV is getting cheap enough that one could just install more PV instead of installing solar thermal. That’s an attractive idea, but there are a couple of flaws with that plan:

  1. Comparing PV to a $10,000 solar thermal system would be favorable. Our systems cost much less than that.
  2. Solar thermal collectors are 5x more efficient than solar PV panels. So you would need 5x the amount of roof space to produce the same amount of heat.
  3. Most water heaters in the U.S. burn natural gas. In addition to causing fracking, natural gas is very notably not electricity. You can create as much electricity on your roof as you’d like, but as long as you heat your water with natural gas none of that electricity is going to save you money on water heating or offset the emissions from the natural gas you’re burning. And switching to an electric water heater is going to come at a cost AND is very difficult to do in some states. In California, for example, the California Energy Commission has made electrical water heater all but illegal. In their words:

“Since electric TDV is much higher (per unit of energy content) than gas, electric resistance water heating is essentially precluded unless it is used in conjunction with an adequately sized solar water heating system.” 2013 Residential Compliance Manual, Chapter 5

The main argument against solar water heating, however, was an economic one, based on a $10,000 solar water heating system. The Sunbank costs much less than that and also benefits from state and federal incentives (while they last).

Build It From Scratch

The other end of the do-it-yourself spectrum (from not installing thermal at all) is the build it from scratch model. We don’t have a problem with this. If tinkering is your thing and you want to build a solar thermal system out of old coke bottles, then go for it. And send us photos! But there is a reason that professional manufacturing exists. After you spend a lot of time and a surprising amount of money on materials, you’ll be left with an inefficient solar water heater that relies on it being hot outside in order for it to provide noticeable solar gain.

Between not installing solar thermal at all, and doing it from scratch, is where we fit in. We inhabit the sweet spot for do-it-yourselfers who want to complete a project in a weekend and have a reliable solar thermal system that will offset their consumption of fracked natural gas.

Installing a DIY Solar Water Heater

One thing that can often intimidate the DIY solar water heater installer is plumbing. But it turns out that plumbing truly is not rocket science (who knew?). And the internet is also a great plumbing instructor. For example, we recommend PEX piping on our projects because it is an inexpensive and easy to install alternative to copper.

Here’s a quick video that shows you how to make PEX crimp connections:

There’s more where this came from.

Give us a call!

(888) 385 0005

850 Front Street #7212
Santa Cruz, CA 95060

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Sunbank SB-80G

80 Gallon Solar Water Heater $3,999 ($2,799 after tax credit)