The sun is the most powerful energy source available to us on earth. All living things are powered by the sun. If you are wondering how to make better use of the suns rays, the free energy it's constantly blasting out, you're not alone. Let's try and use this resource as much as possible. This can be achieved through a solar panel water heater.

Using the Sun While Shading the Roof

If you read my article on how solar PV panels helps shade the roof, you will also recognize that a solar water collector will give the same benefit. Any sun you block before it hits the roof will help lower the cooling that the A/C has to do. Because PV arrays cover more area, the benefit from the shade of a solar water collector will be less dramatic.

How the Collector Works

The solar water heating system is a simple device to take the free energy from the sun and use it to heat waterworks by pumping water through a series of tubes that are set up, typically on a roof top, and angled to receive full exposure to the sun's rays. This is not the same water that will appear in your shower or sink. It is a separate closed loop system.

The rest of the water system - closed loop exchange

The heated water from the solar water collector on the roof will run through a pipe to a separate Heat Exchanger. This smaller tank facilitates heat transfer by conduction... between the domestic loop and the rooftop loop. The Heat Exchanger also serves as the drainback tank for the roof unit. The energy from the bath in the exchanger will transfer to the domestic loop until the temperatures in both equalize. On the other side, the domestic loop comes from the home's traditional (existing) water heater tank and enters the exchanger, coiling through it and exiting to return again to the powered tank. This means the temperature in the domestic loop will be higher coming out than it did when it went in.

It doesn't replace the powered water heater - Pre-heater

Yes, you heard right. Unless your goal is to live 'off the grid', You still need a traditional water heater (powered by electricity, natural gas, etc). to be your backup hot water. It will turn on during cold nights and cooler seasons of the year. (You like taking showers in the morning, right?). So how do solar water panels contribute? In this setup, it's best to think of the rooftop unit as a solar water PRE-heater. Instead of your powered unit taking the temperature of the water all the way from 65 degrees to 110, You'll save a lot of energy if the sun takes your water from 65 to 85 for free. Then the traditional heater only has to take it the last 25 degrees.

Does it make sense (cents)?

Homeowners that are looking to utilize solar energy can benefit from current tax breaks and subsidies that exist (but will likely expire in a few short years). In addition to these incentives, solar water heating systems are less expensive than electrical solar panels, and are seeing a payoff in 3 to 5 years, versus the 12-15 year payoff for a PV array installation. Since home owners pick up and move every 5 to 7 years on average, the payoff will occur while they are still living in the home, making it a more attractive investment.

So what does all of this mean to the homeowner interested in making an intelligent investment? Folks typically enter the market excited about a PV solar panel system. After doing the research and analyzing the required investment, they often prefer the the less intensive, earlier payoff of solar water panels. As the benefits come in, these homeowners are likely to be the first on the block to have a PV system installed in coming years.