By far the most popular options for residential and commercial applications are mono- and poly-crystalline photovoltaic panels. Photovoltaic cells are constructed using silicon doping and lithography techniques similar to those used to build microprocessors. Typically mono-crystalline PV cells produce more energy than poly-crystalline designs, but are often more expensive to produce. The cost per watt ratios of both technologies are affordable for a variety of commercial and residential applications.
Thin film solar panels are constructed using different materials but similar semiconductor manufacturing techniques as mono- and poly-crystalline cells. Because thin film technologies do not need a silicon substrate, thin film technologies allow the production of much larger, thinner, and even flexible cells instead of the small yet efficient cells of their silicon-based competitors. Although thin film panels have yet to reach the same energy production capacity and cost per watt of their competitors, they offer unique benefits such as new and innovative integrated construction techniques and the option of attractive translucent panels.
Residential solar water heating technologies often use a collection of narrow tubes resembling fluorescent lights to capture heat from the sun and transfer that to water coming from a municipal source. This is often not enough to supply a typical home with on-demand water heating so these systems are used as a supplement to tank and tank-less water heating options and can dramatically reduce the amount of energy used to heat water in a typical home. Due to U.S. regulations, residential water heating options are often more expensive than typical solar pool heating technologies due to added complexity and safety measures. One direct benefit of this added complexity is an increase in reliability and a reduction in maintenance costs over the lifetime of the system.
For years solar pool heating options produced excellent results in their first few years but soon caused a variety of headaches such as leaks and cracks that have led many customers to use natural gas fired heaters instead. Thankfully there are new thermal collector designs on the market today that are better performing, longer lasting, and more attractive than past designs. Utilizing extra roof space over a garage, home roof, or even a gazebo, a typical residential customer may never need to use a single dollar of natural gas to heat their pool during the summertime. Given enough usable space to install panels, many large commercial customers such as water parks and public pools have found a dramatic drop in operating costs by adding solar pool heating.