The municipal waste is disposed in open dumps outside city limits that facilitate breeding ground for flies, mosquitoes, cockroaches, rats and other such pests.
SPV systems convert solar energy directly into electrical energy. There are no moving parts.
The basic conversion device used is known as a solar cell.
Commercial solar cells have efficiencies in the range of 10-20% and can produce electrical energy of 1-2 kWh/m2/day in ordinary sunshine.
A solar cell has lifespan in excess of 20 years.
Other Advantages of SPV System
SPV system is reliable, modular, durable, and generally maintenance-free.
It is quiet, compatible with almost all environments, responds instantaneously to solar radiation.
Some Disadvantages of SPV System
At present, the cost of solar cells are high making them economically uncompetitive with other conventional power sources.
The efficiency of solar cells is low. As solar radiation density is also low, a large area of solar cell modules are required to generate sufficient useful power.
Solar Cell
The fundamental power unit of a PV system is a solar cell.
Individual cells are attached to a base called a back-plane which is usually a layer of metal to physically reinforce the cells and provide electrical contact at the bottom.
Currently available types of cells are single crystal silicon, polycrystalline silicon, amorphous silicon, cadmium telluride, and copper indium diselenide.
Most PV cells (more than 90%) are of crystalline silicon type with efficiencies between 14 to 17%.
SPV Module
A single solar cell cannot be used for energy generation because the output is very small, and it requires protection against dust, moisture, mechanical shocks and outdoor harsh conditions.
The basic building block of SPV system is a solar module which consists of an appropriate number of cells fixed on a durable back cover, with a transparent cover on top, and hermetically sealed to make it suitable for outdoor applications.
Most common commercial modules have a series connection of 32 or 36 silicon cells to make it capable of charging a 12-V storage battery.
SPV Panel
Several SPV modules are connected in series/parallel to increase the voltage/current rating.
SPV panel is a group of several modules connected in a series-parallel combination in a frame that can be mounted on a structure.
SPV Array
Large number of inter-connected SPV panels are known as SPV array.
It is important to ensure that an installed panel does not cast its shadow on the surface of its neighboring panels.
Layout and the mechanical design of SPV array such as tilt angle of panels, height of panels, clearance among the panels etc are carried out taking into consideration the local climatic conditions, ease of maintenance etc.
Balance of System
All system components other than the SPV panels are termed as the balance of system (BoS).
Other components generally include inverter, support structure, and wiring and cabling.
