Solar Volts

Welcome to Solar Volts Blog. This blog is active, full of knowledge and practical tips and tools. This blog is about solar energy and Photovoltaic (PV) systems. 

Photovoltaic systems can use sun to power people electricity needs. Its operating principle was first discovered in 1839 by a French physicist named A. E. Becquerel. In 1950, Bell Labs developed first practical PV module that was used in space application. After 1970, people start charging their batteries using these modules. Now PVs are used in industry as well as in homes. 

One important point that all of us should remember that PV systems are not the right answer for all applications because:

• The sun cannot provide you the twenty four hours of energy. 
• The area required for PV system installation is comparably very large with other systems that provide power. 

There are two main types of PV systems:

1. Grid Direct PV Systems
2. Battery Backed PV Systems

Grid Direct PV Systems: These systems are directly connected with the utility grid. They are also know as utility interactive. They send power back to the utility grid when the user is idle (no power consumption). For most of the people in developed countries who have utility power do not face power outage. If accidentally, power breakdown occur, it is generally of short duration. 

Battery Backed PV Systems: These systems are either connected with the national utility grid or disconnected with it. Therefore these systems are known as utility interactive in former case and independent stand-alone in later case. In case of stand-alone PV system, no power is sent back in utility grid. These systems are used for off-grid or offline applications. For storage of solar energy, batteries are used. These batteries provide us backup of energy during night.

Any PV system consists of following essential components:

1. PV Modules, commonly know as Solar Panels
2. Solar Charge Controllers (optional)
3. Battery Bank
4. Inverters
5. Safety Devices

PV Modules are units that we have to place in the sun to produce electricity. These modules generate variable voltage and variable current depending on the availability of sun. Number of these modules can be connected together to form PV Array.

Solar Charge Controllers are used in stand-alone PV systems. They are used to charge batteries. They control voltage and current generated by PV module at required levels. 

Battery Bank is used to store energy produced by PV array. Batteries store solar energy in the form of electrical energy. The output of the battery bank is Direct Current (DC). Whenever we use battery bank we need to define the following parameters:

• The amount of energy the user needs daily.
• The amount of solar energy that's available for charging. 
• The temperature at which the batteries are placed.

Inverter takes DC and convert it into the Alternating Current (AC). It is necessary as most of the appliances or loads in home or industry need AC. In terms of power, inverters convert DC power (stored in battery) into AC power (used by appliances). 

Safety Devices provides safety. Safety is one of the most important consideration in designing, handling and installation of PV systems. The first thing is the best choice of wires. Wires have to carry current and suffer huge temperature as well as other environmental effects. Other safety devices include circuit breakers, over-voltage protectors, under-voltage protectors and Ground Fault Protectors (GFP) etc.

All these components connected together intelligently and effectively using proper design skills can fulfill your electricity needs for at-least fifteen years and more! Is it cool?