seminar about solar electricity

2.  Our aim is to use solar energy for household loads using an
inverter. Solar energy is converted to electrical energy by photo-
voltaic(PV) cells. This energy is stored in batteries during day
time for the utilization purpose whenever required.
 A solar inverter, or PV inverter, converts the direct current (DC)
output of a photovoltaic solar panel into a utility frequency
alternating current (AC) that can be fed into a commercial
electrical grid or used by a local, off-line electrical network.
INTRODUCTION

3. PROJECT BLOCK DIAGRAM

4. CLASSIFICATION OF SOLAR SYSTEM
 Stand-alone system (off-grid system)
 Grid-tie system (on-grid system)

5. STAND-ALONE SYSTEM
 Stand-alone PV systems are designed to operate independent of the
electric utility grid, and are generally designed and sized to supply
certain DC and/or AC electrical loads.
 The inverter draws its DC energy from batteries charged by
photovoltaic arrays.
 Normally these do not interface in any way with the utility grid.

6. STAND ALONE SYSTEM COMPONENTS

7. GRID-TIE SYSTEM
 Grid-tie inverters convert DC electrical power into AC power
suitable for injecting into the electric utility company grid.
 Grid Tie System is the simplest and most cost effective way to
connect PV modules to regular utility power.
 Grid-Connected systems can supply solar power to your home and
use utility power as a backup.
 If your system is generating more power than you are using, the
excess will flow back into the grid, turning your meter backwards.

8. GRID TIE SYSTEM COMPONENTS

9. HARDWARE REQUIREMENTS
 Step up Transformer
 MOSFET
 PWM Inverter
 Solar Panel
 Battery
 PIC16f877

10. SOLAR PANEL
 Solar panel refers to a panel designed to
absorb the sun's rays as a source of energy for
generating electricity.
 Expose the cell to light, and the energy from
each photon (light particle) hitting the silicon,
will liberate an electron and a corresponding
hole.
 This flow of electrons is a current; the
electrical field in the cell causes a voltage and
the product of these two is power
 Solar panel is an array of Several solar cells
(Photovoltaic cells).

11. ABOUT THE INVERTER
 The energy generated by the solar panel, in
the form of direct current (DC), is
transmitted to the inverter. The job of the
inverter is to convert the DC power to
alternating current (AC) that is transmitted
on the grid.
 The transformer will then step up the
voltage from 12 volts to 230volts, which is
the voltage used throughout the Indian
electrical grid. This conversion of voltage is
what allows a 12 volt DC solar panel to be
tied into a 230 volt AC grid.

12. PWM INVERTER
 Pulse Width Modulation or PWM
technology is used in Inverters to give
a steady output voltage of 230 or 110
V AC irrespective of the load.
 The Inverters based on the PWM
technology are more superior to the
conventional inverters.
 The use of MOSFETs in the output
stage and the PWM technology makes
these inverters ideal for all types of
loads.

13. ADVANTAGE OF PULSE WIDTH MODULATION
 In a standard Inverter without the PWM technology, the
output voltage changes according to the power consumption
of the load. The PWM technology corrects the output voltage
according to the value of the load by changing the Width of
the switching frequency in the oscillator section.
 As a result of this, the AC voltage from the Inverter changes
depending on the width of the switching pulse. To achieve this
effect, the PWM Inverter has a PWM controller IC which
takes a part of output through a feedback loop.
 The PWM controller in the Inverter will makes corrections in
the pulse width of the switching pulse based on the feedback
voltage.
 This will cancel the changes in the output voltage and the
Inverter will give a steady output voltage irrespective of the
load characteristics.

14. PIC 16F877
 PIC 16F877 is one of the most advanced
microcontroller from Microchip. This
controller is widely used for experimental
and modern applications because of its low
price, wide range of applications, high
quality, and ease of availability.
 It is ideal for applications such as machine
control applications, measurement devices,
study purpose, and so on.
 The PIC 16F877 features all the
components which modern microcontrollers
normally have.

15. Inverter
String
inverter
Center
inverter
TYPE OF SOLAR INVERTER

16. STRING INVERTERS

17. CENTER INVERTER

18. WHAT IS MPPT ?
It is an electronic system that operates the photovoltaic modules in
a manner to extract the maximum power from the system.
 What is maximum power point ?
It is a operating point at which maximum power can be
extracted from the system. Usually represented as MPP.
 The output of solar module is a function of solar irradiance,
temperature.
 Generally MPPT is installed in between PV system and inverter
Coupling to the load for maximum power transfer may required either
providing a higher voltage at lower current or lower voltage at higher
current.

19. APPLICATIONS
 Can use solar inverter for domestic application.
 It can be plugs in your house for your TV, computer, and other
wired products.
 Can use Solar Power Inverters For Industrial Application.

20. ADVANTAGES
 High efficiency and outstanding energy harvest in a small
modular design.
 Ease of installation to save time and money.
 Is compatible with other GT Series models to customize the
inverters to the array.
 Central and micro inverters can be up to 95% efficient.

21. DISADVANTAGES
 Central inverters is difficult to do properly and is usually the
hardest part of designing a solar array.
 For central inverter, the output from your whole array can drop
significantly, if any one of the panel is shaded.
 Another weakness of a central inverter is that you won’t be able
to monitor how each individual panel is performing.