PV Modules

Photovoltaic panels take advantage of solar energy and convert it to electrical. Depending from cell technology PV panels are separated in 3 categories: Polycrystalline with mean efficiency of 11-14%, Monocrystalline with mean efficiency 12-16% and in amorphous with efficiency of 6-8% respectively.

One PV can produce 6 times its nominal power during summer and 3.5 times during winter per day. Thus from a PV of 100 W we can expect 550-600 Wh (0,6 KWh, kilowatt-hours) of power in the summer and an average of 350 Wh (0,35 KWh) in winter per day.

Namely, the winter energy output derives after dividing the total monthly production of energy in kWh with the days of the month to give as the 350 Wh number.

Per 1000 Watt/p of PV, the total annual production in kWh will be from 1100 kWh (south Greece) up to 1450 kWh (north Greece). So a panel of 100 Wp will produce from 110 kWh up to 140 kWh a year.

Depending from the application of use PV systems are separated in two categories: Stand alone PV systems and grid connected systems. In grid connected systems the energy produced is sold onto the grid. In stand alone systems the energy is stored in batteries and can be used in periods with low irradiation or during the night. Stand alone systems can be easily converted in hybrids with the addition of a wind generator or a diesel generator.