There is so much attention to Solar PV panels right now, that solar water heaters are missing all the limelight.

What’s the difference between Solar PV Panels and Solar Water Heater Panels?

If you are new to learning about both renewable energy and energy efficiency, the first thing you’ll want to do know is that there are three ways to extract heat (or energy) from the sun for your home.

  1. Heat water using the sun’s energy. Usually in black conduit placed under the sun’s rays. Also called a Direct Circulation System.
  2. Heat a transfer fluid using the sun’s energy, then use the heat captured and transfer it to another medium, like your hot water tank or radiant-filled floors. Indirect Circulation System.
  3. Use Photovoltaic (PV) panels to convert the sun’s energy to electricity. Learn more about Solar PV Systems here.

When you hear that the domestic water is heated by Solar in a home, it’s most  likely via a heat transfer fluid. Although technically, if you have Solar PV panels and an electric water heater, you are heating your water using Solar energy.

Why is a Heat Transfer Fluid and Heat Exchanger Necessary?

The simplest method of heating water is the way outback campers heat their water. Fill a container with water, leave it in the sun for a few hours and viola, hot or at least warm water.  You can do the same for your home, but the drawback occurs when the sun is either too hot; creating unsafe water temperatures, or too cold creating an opportunity for your system to freeze and crack all the plumbing features of your solar water heating system.

A heat transfer fluid is specifically chosen based on the climate you live in. For example, if you live in a hot desert climate, a fluid with a high boiling point will be selected and conversely if you are in a Northern cold climate, a fluid with a low freezing point will be selected.

How Much Can You Save Using a Solar Water Heater?

Source: 2011 Buildings Energy Data Book, Section 2.0.

Source: 2011 Buildings Energy Data Book, Section 2.0.

The U.S. Department of Energy estimates that 18% of a household’s energy is used to heat water. So if you are an average user, it stands to reason that 18% of your energy bill could be offset to some degree by choosing a renewable source.

Solar Water Heater systems almost always require a backup to accommodate increased demand, late night and early morning use or periods of cloudy days.

As with any renewable or energy efficiency appliance, how the appliance is used can skew any numbers. If you love long hot showers or baths after a day of work, the savings will be higher than the person who takes a quick cold shower early in the morning. Learn more about the cost and savings of Solar Water Heaters here.

Additionally, the cost to retrofit an existing system can sometimes be cost restrictive. If you are building a new home, the cost may be more upfront, yet quickly offset with both rebates, energy savings and the ability to amortize this benefit over a 30 year mortgage period. Either way, check out the Database Renewable & Efficiency incentives frequently by clicking here. Solar water heating may not be right for every home. Check out Hybrid Water Heaters, another cool way to heat water.

Talk to Your Builder

I work with a Network of Green Certified Realtors Across the County. Click here for a GREEN certified agent near you.

I work with a Network of Green Certified Realtors Across the County. Click here for a GREEN certified agent near you.

Talk to your builder about using renewable energy in your design, not only will it lower your carbon footprint, but for the entire life of the home (which may be longer than yours) the home itself will have a lower carbon footprint. If your builder tells you that energy-efficient upgrades or renewables are not worth the cost without running numbers, consider another builder. If they tell you that current codes are so strict that you don’t need additional energy efficiencies, you’re being Green Washed. There is a difference and builders who build with this in mind have done the math to prove it.

Image Credit: “Calentador Solar de agua instalado en techo de vivienda” by Tony Woon, [Licensed under CC BY 3.0] via Wikimedia Commons