Photovoltaics (PV) already offers a competitive alternative in many high value applications. For example, in low power instrumentation ( e.g. traffic counters, calculaters, etc.), PV is commonly preferred over batteries. The evolution of new and appropriate application for PV play a significant role in bridgin the PV market from where it is today to the future and bulk power generation. PV can be concidered a practical alternative wherever
- Cost does not make it unacceptable;
- PV can perform reliably in the specific application and location; and,
- A practical size array produces sufficient energy
As with any commodity, cost plays a prominent role. However, being the lowest priced alternative is not always necessary. Applied in niche market applications, PV´s favorable extrinsic features can outwaigh an otherwise higher price. Once it is a assure that price alone does not eliminate PV as an opliton, preformance characteristics can be compared agaist those of other energy options. PV has intrinsic properties which can make it favorable in some applications, inappropriate in others. Some of the favorable properties of PV are that it is mobile, decentralized/ independent, modular, quiet and non-polluting, has low maintenance costs.
These are balanced against unfavorable characteristics which can make PV unsuitable in many applications, such as low energy per square meter, large dependence on climate in each region, fragile, heavy and, mostly, Intermitten/ non-deterministic energy production.
The best candidate applications which mach PV´s strong poins are to be found in electrical loads with some combination of these following characteristics: remote and inaccessible to the grid; small, daytime only; outdoors or with outdoor access; conventionally powerd by an expensive energy source; difficult to service or fuel. Using these guidelines, several major market secors that offer favorable new applications for PV are as follows:
- Remote Instromentation and Monitoring
- Commercial and Industrial Ligtning and Signage
- Water purification
- Building Envelope Temperature Control
- National Defense
What is the physical process that is used to produce energy by using Photovoltaics?
Sunlight basically consists of small packages of energy called photons. Photons have different amounts of energy depending on the wavelength of the solar spectrum. For example, the blue colour or ultraviolet have more energy than red or infra-red.
When the photons collide to a photovoltaic element (that basically is a semiconductor), some are reflected, others pass through it and others are absorbed by the photovoltaic element. The latter are the ones that produce electricity. They force the electrons of the photovoltaic to move to a different position and, as known, electricity is nothing more then the movement of electrons. So, one of the more advanced technologies for production of electricity nowadays is based on this simple physical principle.