--Solar Cells On the Roof of Small


The main goal of this group is to research and develop a maximally efficient and useful solar power system that will be installed on the roof of Small Hall after its renovation in 2009 2010.

There are many various types of solar cells, optimized for best performance at various conditions. Thus, it is very important to identify the right technology to use, in terms of year-around efficiency, durability and installation and maintenance cost. Unfortunately, the information provided by manufacturers is often very insufficient to make an educated decision. Our group has purchased several small solar panels of different types and different manufacturers to run long-term side-by-side comparison of various technologies. This will provide the information about expected electric power production variation throughout the day, seasonal changes, and dependence on the weather conditions. Being able to test all or at least some panels would be ideal and give us the best opportunity to decide which panels will be the best to use for the physics building. To gather the information about solar panels power output and weather conditions remotely, we will install a sensor network on the roof of Small hall.

We will be monitoring several parameters to address the following questions:

  1. Performance of different types of solar panels under different light conditions (direct sun vs scattered light). We will then try to obtain the information about average number of sunny and cloudy days to determine which technology can provide the maximum amount of power for us.
  2. Study of temperature sensitivity of solar panels, including testing cells on different roofing materials.
  3. Long-term variations of solar cell performance, including seasonal changes and any natural dust accumulating on the surface. The latter can help evaluating the amount of maintenance work required to keep the system operating efficiently.
  4. Study of optimal solar panel mounting. While our research showed that any active tracking system will not be efficient for our relatively small system, we will have to determine if it makes sense to mount the panels horizontally, or at some angle with the horizon to optimize their performance.

In addition to finding the optimal solar technology, our goals is also to developed the most efficient way to integrate solar-generated electrical power into the Small Hall infrastructure. To better understand the limitations of such energy source we are planning to put together a prototype system: the computer we will use for all the monitoring and data acquisition tests will be 100% solar powered. We have purchased one large solar panel with enough wattage to power a laptop computer. This closed loop system will contain a DC to AC inverter to convert the solar power output to sinusoidal 110VAC, a DD battery to continue the operation at night, as well as a charge controller to measure and regulate the solar panel output current. The development and long-range operation of such a small-scale prototype system will allow testing and debugging the integration of the solar power system into the existing electrical grid of the building.