When subsidies are included, I found out that for my condo in Arlington, VA, a SWHS would pay for itself in 2-4 years as opposed to about 30 years for a PV system. Since SWHS are much more efficient than PV systems (in electrical energy equivalent per area), you could even install a solar water heater and still have room for some PV panels if you wanted them and the local conditions are favorable.
While I am excited about the evolving technology behind commercial solar power plants, using the sun to heat water in your home is a no-brainer if you can afford to pay for the initial cost while gas savings pay you back. As the cost of natural gas rises (and drilling puts more pressure on natural areas) this will likely become even more appealing.
Those still interested in residential PV systems may be interested in a cost calculator, and if you really want to understand the technology the Department of Energy has a very detailed handbook available which covers both PV and SWHS. Installing a PV system in your home is still a great idea if you’ve already taken care of easier green improvements (including a SWHS) and still want to do more, especially in states with lots of sun and good subsidies.
If you’re on the fence, an energy audit is an excellent way to find out what the easiest and most effective changes you can make around your home to ensure that you can put your conservation dollars to the most good.
1. Note that Dr. Borensteinís estimates are controversial; read one of his major analyses of solar’s costs and benefits, two critiques of his work (by Bill Powers and Tom Beach/Patrick McGuire), and his response to those critiques.
Jon Fisher is a data management specialist for The Nature Conservancy, the world’s leading conservation organization. He has studied forestry, environmental biology, stream ecology, environmental engineering and how technology and spatial analysis can improve wildlife management at airports. He also loves to cook delicious vegan food. Opinions expressed here are the personal opinions of the author and do not necessarily reflect the views of The Nature Conservancy.
(Image: President Nasheed of the Maldives installs solar panels on his home in Male, Maldives. Source: 350.org via a Creative Commons license.)