Photovoltaics

PV Applications

Multicrystalline silicon casting, wafers, and PV cells ( Photovoltaics

PV cells Photovoltaics

Cross-sectional view of a PV cell, showing the photo-receptive surface and the p/n junction Photovoltaics

An n-type material has an increased number of electrons the p-type material has vacancies as a result of missing electrons (p = positive). The p-n junction is the critical component of a functioning solar cell. Photovoltaics The Photovoltaic Principle - Cells

The majority of the light is absorbed in the “p-silicon” layer some electrons push through the p-n junction into the n-silicon layer. The freed electrons flow through the wire grid Photovoltaics The Photovoltaic Principle

One single-crystal silicon solar cell with a surface area of approximately 100 cm2 (16 in2) generates a current of 3 A at a voltage of 0.5 V when exposed to full sunshine. Photovoltaics The Photovoltaic Principle

Photovoltaics Efficiencies

Photovoltaics PV Modules

Flexible photovoltaic modules made of amorphous silicon (a-Si) on stain - less steel Photovoltaics

The light-generated current flows out of the cell surface and through a metal grid called the front contact. The cell’s bottom layer is called the back contact and forms a bridge to an external circuit. Photovoltaics The Photovoltaic Principle - Modules

I-V curve and characteristic parameters for a typical module Photovoltaics

Open circuit voltage (VOC): no current. Pn under STC: peak power (Vn and In). Short circuit current (ISC) Photovoltaics The Photovoltaic Principle - Modules

An example of a typical PV module data sheet Photovoltaics Solar cells 100 mm x 100 mm, 36 in series

Voltage is derated by V/K above STC In bright sunlight module is 35°F-70°F above the ambient temperature. Photovoltaics The Photovoltaic Principle - Modules

Photovoltaics PV System Arrangement

Photovoltaics

Advantages of PV

Photovoltaics Industry Claim

Photovoltaics *)Assuming volume installations. Individual rooftop systems can be up to twice this price

Photovoltaics More Cautious AEE Assessment

Photovoltaics

Holographic PV Planer Concentrator - HPPC

Photovoltaics Holographic PV Planer Concentrator - HPPC

Solar Thermal

Conventional Flat Plate Collector

Solar Thermal Passive Thermo-siphon Collector

Solar Thermal Evacuated Tube Collector

Solar Thermal Solar Hot Water System

Solar Thermal