Web viewOpen circuit voltage: 37.25V. Mounting Arrangement. ... Inverter/Power Conditioning Unit(PCU) No.of units: 1 Nos. Rated capacity: 20kW. Input voltage range: 350

Transcend Solar systems & SolutionsTransferring to Green

CONTENTS

Executive summary............................................................................Salient features INTRODUCTION

ELEMENTS INCLUDED IN A SYSTEM OF PHOTOVOLTAIC CONVERSION

EXISTING POWER SUPPLY ARRANGEMENTS:

LV DISTRIBUTION SYSTEM LAYOUT

Solar availability and the details of the irradiances:

PROTECTION AND CONTROLS:

INTEGRATION OF PV POWER WITH GRID:


EXECUTIVE SUMMARY

The proposed Roof Top Solar Photovoltaic Power Plant at the site of 186sq.m^2

would utilize vacant area of about 952 sq. m. available on the roof top. The SPV

power plant with proposed capacity of 20 kWp would be connected to grid. No

battery storage has been provided. It would meet partial load of the building

during working days and feed the surplus power available to the grid during week

end and holidays.

The 20 kWp SPV power plant is estimated to afford average annual energy feed of

38.44 (PCU) as 94% and losses as 3% in the DC and AC system. The Plant would

operate at a daily capacity utilization factor of 8.5%. The energy available from

the Plant would vary from a minimum of 2.5 MWh during the month of November

to a maximum of 4.092 MWh during the month of March.

The SPV Power Plant is estimated to cost Rs. 20 Lakhs based on the normative


SALIENT FEATURES

1) Location

a) Site Address : The Madras Pharmaceuticals,Karpakkam

b) Latitude : +13.09 (13°05'24"N)

c) Longitude : +80.27 (80°16'12"E)

2) Area of the SPV plant

a) Length

b) Width

c) Location

3) SPV Power Plant

a) Output 20Kwp

b) No.of Modules 80

c) No.of modules in series 40


d) DC bus 1No.

4) Technical details of the SPV module

a) PV module type : Poly crystalline

b) Physical dimensions

i) Length : 1639mm

ii) Width :982mm

iii) Thickness : 35mm

c) Electrical Parameters

5) Maximum power ratingi) Rated current :29.95 V

ii) Rated voltage : 8.35 A

iii) Short circuit current : 8.95A

iv) Open circuit voltage : 37.25V

6) Mounting Arrangement

i) Mounting : Ms structure with coating

ii) Tilt angle(slope) of PV module: 13 deg


7) Inverter/Power Conditioning Unit(PCU)

i. No.of units : 1 Nos.

ii. Rated capacity : 20kW

iii. Input voltage range : 350 – 1000V

iv. Output voltage : 415V

v. Frequency : 50Hz

vi. Efficiency : 98.7%

8) Grid connection details

i) Electrical parameters for interconnection

9) Annual Energy Generation

Cost Estimate :

Construction time

INTRODUCTION

In one minute, the sun provides enough energy to supply the world‟s energy needs for one year. In one day, it provides more energy than the world‟s population could consume in 27years. The energy is free and the supply is unlimited. All we need to do is find a way to use it. The largest solar electric generating plant in the world produces a maximum of354 megawatts (MW) of electricity and is located at Kramer Junction, California. Since India has abundant sources of RE especially sunlight, it can cater to all the energy needs of the country. The country receives an average radiation of 5 KWh per square meter (m) per day and with 2300 to 3200 sunshine hours per year. The potential of solar photovoltaic has therefore been estimated at 20 MW per square km.


Conversion from Solar energy into Electrical energy

There are 2 ways to convert the solar energy into electrical energy

1) Solar thermal

2) Solar photovoltaic system

Solar photovoltaic systems are superior when compared to the solar thermal system where the solar thermal system can only use the direct irradiance of the power generation whereas the solar photovoltaic system can convert the diffuse irradiance as well. That means that, they can produce electricity even with cloud –covered skies.

So the Solar photovoltaic solutions are preferred one when compare to solar thermal systems.

ELEMENTS INCLUDED IN A SYSTEM OF PHOTOVOLTAIC CONVERSIONThe main elements that can be included in a system of photovoltaic systems are

Solar Panels

The solar panel is the power source of all photovoltaic Installation. It is the result of a set of photovoltaic cells in series and parallel. Solar panel gives power to battery or inverter through charge controller (Regulator).

Solar charge controllers:

It is the element to protect the battery against to risking situations as overloads and over discharges. The theoretical formulation of the model can be simple, although it is necessary to consider the peculiar


discontinuities of the model and the inter-performance with the rest of the analyzed models.

Inverter:

The inverter allows transforming the DC current to AC. A photovoltaic installation that incorporates an inverter can belong to two different situations, based on the characteristics of the alternating network. In first an isolated system, where the inverter is the element of the network and has to feed the set of loads and in second situation the inverter is connected to the public network, to which it sends the energy generated by the system.

Batteries

Normally they have been considered as a simple element of storage of Electrical energy. Batteries are often sold with a PV system. The primary purpose is to store the electricity not immediately used, which could be used at some later time. With net metering, the value of batteries is less because the utility grid basically acts as a storage facility. For a reliable generation system that can function independent of the utility grid, however, batteries may be a viable component to the total system. Backup generators may be included in a system to provide power when the PV system is not operating, and are generally included when systems are not grid connected.

Types of Photovoltaic systems

There are two types of photovoltaic system generally used in the houses, Industries and power plant generation.


Grid Connected PV Systems

These systems are connected to a broader electricity network. The PV system is connected to the utility grid using a high quality inverter, which converts DC power from the solar array into AC power that conforms to the grid‟s electrical requirements. During the day, the solar electricity generated by the system is either used immediately or sold off to electricity supply companies. In the evening, when the system is unable to supply immediate power, electricity can be bought back from the network.

Standalone Systems:

PV systems not connected to the electric utility grid are known as Off Grid PV Systems and also called „stand-alone systems.‟ direct systems use the PV Power immediately as it is produced, while battery storage systems can store energy to be used at a later time, either at night or during cloudy weather. These systems are used in isolation of electricity grids, and may be lighting and general loads. PV systems also provide invaluable and affordable electricity in developing countries like India, where conventional electricity grids are unreliable or non-existent.

SITE DESCRIPTION:

The roof top is having an area of close to 952.8 sq.m of area where it is proposed to utilize the vacant area on the roof top for installation of 20 kWp which could serve as a grid connected system and could be used for collection of data for analysis on the of availability of solar power.

Plant is having around sq.ft of rooftop which will be used to for installing ON grid solar solutions to the industry.

The data are collected from the recent metrological data, the details as follows.


Chennai, India - Solar energy and surface meteorology

From the above figure of the data the average solar irradiance is 5.273kWh/m^2/day, and the maximum wind speed is 5.52m/sec. The sun path direction of the solar system is

The basic information at the site is:

Latitude: +13.09 (13°05'24"N)Longitude: +80.27 (80°16'12"E)


FUNCTIONAL DESCRIPTION OF SPV POWER SYSTEM

The solar PV system shall be designed with either mono/ poly crystalline silicon

modules or using thin film photovoltaic cells or any other superior technology

having higher efficiency.

Three key elements in a solar cell form the basis of their manufacturing

technology. The first is the semiconductor, which absorbs light and converts sit

into electron-hole pairs. The second is the semiconductor junction, which

separates the photo-generated carriers (electrons and holes), and the third is the

contacts on the front and back of the cell that allow the current to flow to the

external circuit. The two main categories of technology are defined by the choice

of the semiconductor: either crystalline silicon in a wafer form

or thin films of other materials.

The grid interactive roof top solar PV system generally comprises thefollowing equipment.

i) SPV Power Sourceii) Inverter (PCU)iii) Mounting Structureiv) AC and DC Cablesv) Earthing equipment /materialvi) Junction Boxes or combinersvii) Instruments and protection equipments

Photovoltaic solar system use the light available from the sun to generate

electricity and feed this into the main electricity grid or load as the case may


be. The PV panels convert the light reaching them into DC power. The amount of

power they produce is roughly proportional to the intensity and the angle of the

light reaching them. They are therefore positioned to take maximum advantage

of available sunlight within site constraints. Maximum power is obtained when

the panels are able to 'track' the sun's movements during the day and the various

seasons. However, these tracking mechanisms tend to add a fair bit to the cost of

the system, so a most of installations either have fixed panels or compromise by

Incorporating some limited manual adjustments, which take into account the

different 'elevations' of the sun at various times of the year. The best elevations

vary with the latitude of the load location.

The power generating capacity of a photovoltaic system is denoted in Kilowatt peak (measured at standard test conditions of solar radiation of 1000 W per m2). A common rule of thumb is that average power is equal to 20% of peak power, so that each peak kilowatt of solar array output power corresponds to energy production of 4.8 kWh per day (24 hours x 1 kW x20% = 4.8 kWh)

Solar photovoltaic modules can be developed in various combinations depending upon the requirements of the voltage and power output to be taken from the solar plant. No. of cells and modules may vary depending upon the manufacturer prudent practice

Inverter

i) The DC power produced is fed to inverter for conversion into AC.

ii) The output of the inverter must synchronize automatically to the grid

system based on the voltage and the frequency.


iii) Inverter efficiency of min.94% is considered in the PV system

PROTECTION AND CONTROLS:

i) Inverter shall be provided with islanding protection to isolate it from

the grid in case of no supply, under voltage and over voltage

conditions so that in no case there is any chance of accident.

ii.) In addition to above, PV systems shall be provided with adequate

rating fuses, fuses on inverter input side (DC) as well as output side

(AC) side for overload and short circuit protection and disconnecting

switches to isolate the DC and AC system for maintenances are

needed.

ii) Fuses of adequate rating shall also be provided in each solar array

module to protect them against short circuit.

ANNUAL ENERGY GENERATION:

The annual energy generation from the SPV power plant has been worked out

based on the data on mean global solar radiant exposure over puducherry at

The mean global solar radiant exposure for a complete year is

5.27kWh/m^2/day. Considering the efficiency of PV module at 16% and

temperature coefficient of 4.4 % per deg C, the annual energy generation feed


into the grid is estimated as 38.44 MWh. This takes into consideration an

efficiency of the Power Conditioning

Unit (PCU) as 97% and losses in the DC and AC system as 3% each up to the

point of interconnection. The month wise energy generation during the year is

given below.

Jan Feb Mar April May June July Aug Sep Oct Nov Dec0

500000

1000000

1500000

2000000

2500000

3000000

3500000

4000000

4500000

INTEGRATION OF PV POWER WITH GRID:

The output power from SPV would be fed to the inverter which converts DC

Produced by SPV array to AC and feeds it into the main electricity grid after

Synchronization. In case of grid failure, or low or high voltage, solar PV system

shall be out of synchronization and shall be disconnected from the grid. Once the

DG set comes into service PV system shall again be synchronized with DG supply

and load requirement would be met to the extent of availability of power.


Inverter shall have the software and controls capable of operating the complete

system for safe and efficient operation and includes the Islanding protection, Over

voltage/ under voltage protection, Ground fault /short circuit protection system,

communication equipment such as modems, web box etc, DC reverse polarity

protection, Grid monitoring of all the phases & pole sensitive residual current

monitoring unit, protection against voltage fluctuations in the grid & protection

against internal faults in the power conditioner, operational errors and switching

transients etc.

The output power from inverter would be fed to the panel of common AC bus

system where both the Grid and DG sets are connected. The solar power would

be used locally in on working days to the extent of load in the building and the

generation over and above the requirement of the building would be fed into the

grid. On the week end and other holidays, almost the entire energy from the SPV

module would be fed into the grid. The connection of the grid connected SPV

power plant with the existing power supply system is shown

in the diagram below.


COMMUNICATION INTERFACE:

The project envisages a communication interface which shall be able to

support ( These facilities are being provided as this is a demonstration project)

Real time data logging

Event logging

Supervisory control

Operational modes

Set point editing

Communication System shall be an integral part of inverter. All current values,

previous values up to 40 days and the average values of major parameters shall

be available on the digital bus.


The following parameters shall be measured, displayed and recorded/logged.

Daily plotting of graphs for various parameters shall also be available on demand.

(These facilities are being provided as this is a demonstration project)

15 minute, Daily, monthly & Annual energy generated by the solar system

(kWh)

Solar system temperature

Ambient temperature

Solar irradiation/isolation

AC and DC side voltage and currents

Power factor on AC side

DC injection into the grid (one time measurement at the time of

installation)

Total Current Harmonics distortion in the AC side

Total Voltage Harmonic distortion in AC side

Efficiency of the inverter

Solar system efficiency

Display of I-V curve of the solar system any other parameter considered necessary

by supplier of the solar PV system based on prudent practice.

Data logger system and the software for study of effect of various environmental

& grid parameters on energy generated by the solar system and various analysis

would be required to be provided.


The communication interface shall be suitable to be connected to local computer

and also remotely via the Web using either a standard modem or a GSM / WIFI

modem.


Layout of the Site and the proposed solar power plant location

39.7 m

24.3m

24m

9.8m

4.6m

Proposed Solar

Installation

Combiner Box with Forward diode Inverter

Net meter + Grid

MCCB

Personnel Computer(data logging)


Connection diagram of the whole system.

Documents

Web viewOpen circuit voltage: 37.25V. Mounting Arrangement. ... Inverter/Power Conditioning Unit(PCU) No.of units: 1 Nos. Rated capacity: 20kW. Input voltage range: 350