Photovoltaics

Since the early 1960s PV cells have slowly but steadily come down from prices over $40,000 per watt to current prices of around $3-6 per watt. That is, a 50 Watt panel presently costs about $200. Eight years ago, this same ‘standard’ panel would have cost about $500 at a cost of about $8 - 10 per Watt. The daily energy output from PV panels will vary depending on the orientation, location, daily weather and season. On average, in summer, a panel will produce about five times its rated power output in watt hours per day, and in winter about two times that amount. For example, in summer a 50 watt panel will produce an average of 250 watt-hours of energy, and in winter about 100 watt-hours. (These figures are indicative only, and professional assistance should be sought for more precise calculations.)

Having a large array of PV cells that are able to turn independently to track to sun's movements would be ideal. The tracking motors available today use very little energy and pay for themselves. By capturing the sun's energy, we could easily supplement our current energy budget even it is only a small portion.

Aside from having a large array, another possible use for PV cells would be to use them for on-campus outdoor lighting. Solar cells are suited to such applications, although a storage battery is always required in such systems. They usually consist of a PV panel plus a storage battery, power conditioner and a low voltage, high efficiency DC fluorescent lamp. These systems are very popular in remote areas, especially in developing countries and this is one of the major applications of solar cells. I recommend that we convert at least some of our outdoor campus lighting to photovoltaics as there are many lights on our campus that are primarily for our safety, but still use quite a bit of energy.