Since Bush passed the original bill for the tax incentives and Obama increased them, there have been a lot of questions about solar thermal. My original post on solar thermal talks about the basics of how it works. There are a couple of different options for a retrofit and for new construction.
One of the brands that we sell (Velux) has the option for a 80 gallon tank and 120 gallon tank. In GA, you will get at least 80-85% (on average) of your hot water from the sun. To make up the difference there is an electric element in the tank just like other tank heaters. This only kicks on when the sun cannot keep up with the demand for hot water.
As far as the configurations- if you have a new tank already installed and it is energy efficient, you can have a solar system installed as a preheat for your current system. The electrical element for the solar tank will not be connected since the other tank will provide the backup heat. In new construction you can install a basic systems for 3-4 people and install an electric back up, or you can upgrade to a 120 gallon tank (5-6 people) and add one more collector to the roof.
While the larger systems does cost more, it maintains it’s efficiency for the amount of people using the water so the payback is faster as well.
Here is how the pricing works (on average) here in GA:
80 gallon tank with 2 collectors
Retails cost- 8000
GA credit- 2500 (35% of cost with a max of 2500)
Fed credit 2900 (30% of cost with no cap for 2009_
Net cost 3100
This is about the same cost that a tankless system costs, however the efficiency is much greater- 5-8 times as efficient. This is based on a tankless water heater outperforming a regular tank between 10-20% and solar providing 85% of the hot water. When you divide 85% by the tankless efficiency you can see that Solar is the greener option and will save more money!
To see more of the rebates and credits here in GA visit Get paid to go green!
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