Solar thermal systems
Solar Thermal Systems seek to store heat from the sun that can be used for a variety of purposes. Many different approaches can be employed here, including active systems, such as solar hot water heaters, and passive systems, in which careful engineering design results in a building that automatically stores and utilizes solar energy. Greenhouses are a prime candidate for passive solar design, in which they collect solar energy on sunny days in winter and utilize it to keep the house warm at night.
The main advantages of solar energy are that it is clean, able to operate independently or in conjunction with traditional energy sources, and is remarkably renewable. The main disadvantages are that it is currently more expensive than traditional energy, and the availability of solar radiation varies from day to day, and from season to season. In fact, some parts of Pennsylvania are among the cloudiest spots in the United States. In spite of this, there is still opportunity for using solar energy effectively in Pennsylvania.