Solar Water Heating: the next step in your green routine

By Kendal Hansen
Energy Trust of Oregon

You may have already heard about, or participated in, one of many community driven projects to install solar energy systems on local rooftops. What you may not have heard is that solar energy can not only create electricity but can heat your water, too.

Solar water heaters preheat the water that goes into your existing water heater, saving you energy and money by reducing the amount of gas or electricity your water heater uses. Heating water is one of the biggest energy uses in your home and with solar water heating, the more you use, the more you save. A solar water heating system takes only a fraction of the roof space needed for a solar electric system and can save as much energy as a 2 kilowatt solar electric system. 

If you already have a solar electric system on your roof, solar water heating will reduce energy use in the home, allowing your solar electric system to bank more kilowatt-hours for later use. Systems can be installed as an add-on to your existing water heater or in conjunction with a water heater replacement.

If you own a pool, there is another way you can go solar. With a solar pool heating system, pool water circulates through a large series of collectors – usually located on your roof – where it is warmed by the sun. Installing a solar pool heating system is a great investment with typical payback in 5 years or less.  Not only will you save money, but you may extend your swimming season by using the sun to heat your pool earlier and later in the year. And this year, Energy Trust’s NW Natural customers in Washington are eligible for solar pool heating incentives too.

Cost examples

To make it easy for you, the Energy Trust of Oregon cash incentive is applied up front—like a coupon—reducing the amount you pay to your contractor. Once your project is complete, Energy Trust verifies that your system was properly installed and then reimburses your contractor for the amount of the cash incentive.

The following treatment of tax incentives does not constitute tax advice and cannot be used to avoid IRS penalties. The prices and energy savings listed below are examples only.

Solar water heating system ­– saves 2,400 kWh/year (PGE customer)

$8,500   Total installed cost** 

-  $960   Energy Trust incentive ($0.40/kWh)

$7,540   Amount homeowner pays to contractor

-$1,440 Oregon tax credit ($0.60/kWh, up to $1,500)

-$2,262 Federal tax credit (30% of $7,540)

$3,838   Final cost to homeowner

Solar pool heating system – Seasonal, 400 ft² pool

$5,200   Total installed cost**
- $900    Energy Trust incentive ($3.00/ft² of collector)
$4,300   Amount homeowner pays to contractor
- $1,500 Oregon tax credit ($0.15/kWh, up to $1,500)
$3,160   Final cost to homeowner