Benchmarking solar PV plants on the Basis of EN61724 and methods to maintain the Performance Ratio & Availability

Intersolar Mumbai

15 Dec 2011iPLON GmbH ( Germany)

Victor Thamburaj ( CEO)

Overview

‣ O&M view of PV plant & EN 61724 ‣ Methods to maintain PR and

Availability‣ Real data of Plants in Germany and

Italy‣ iPLON System for O&M needs

EN 61724 and O&M view of PV plant

‣ Structure of Players/ actors in PV Plants‣ Different views of Plays/Actors

‣ EN 61724 and Availibility‣ What does this mean ?

‣ How is it measured ?

‣ O&M View of the Plant‣ PR

‣ Availibility

EN 61724 Standard

Photovoltaic System Performance MonitoringGuidelines for measurement, data exchange and analysis•Introduction•Scope•Normative References•Measured parameters•Monitoring Method• Measurement of irradiance• Ambient air temp• Wind speed• Module temp.

•Data acquisition system•Sampling interval•Documentation•Data format•Check of data quality•Derived parameters

PR = Yield final / Yield reference

This final yield represents the number of hoursper day that the array would need to operateat its rated output power P0 to equal itsmonitored contribution to the net daily load.

This reference yield represents the number of hoursper day during which the solar radiationwould need to be at reference irradiancelevels in order to contribute the same incidentenergy as was monitored

stc

N

stcNref I

HP

I

HPE

**

where

PN is the nominal peak power of the plant (in kWp)H is the irradiation (in kWh/m2) on the panels’ planeIstc is the irradiance value (1.00 kW/m2) in standard test conditions

Reference Energy

The reference energy Eref (in kWh) of the plant is expressed as:

ref

GSE

ref

TGSEPAC E

E

E

FEPR

**

DmPRPR mPACMT *)1(* DmPRPR mPACFAT *)21(*

*251

1

mT TF

Tm is the average temperature of modules (in °C) measured during the test period during daytime (meanwhile irradiation > 200W/m2) is the Power Temperature coefficient of the panels (in absolute value %/°C)

EGSE is the electric energy (in kWh) measured at the GSE metering system *GSEE is the corrected electric energy (in kWh) measured at the GSE metering system

Eref is the reference energy of (section of) the plant (in kWh); δm is the “degradation factor” (0.5%) D is the availability guaranteed (98,5% for each year) FT is a correction factor depending on Temperature, calculated as below:

MEASUREMENT

Irradiation sensor

Energy Metering

Module Temperature

Availability

‣ Plant Level‣ Accumulated hrs where radiation greater than 100 W/m2 = 100 % availibility

‣ Inverter Level‣ Excluded Downtime

‣ Grid issues , spareparts ,emergency

Methods for Maintaining PR and Availibility

‣ „Start „with a Overall Testing Stratgie

‣ „ Have“ a Maintenance Strategie‣ Proactive Method

‣ „Choose“ a O&M Model‣ Third party „experts“(external Innovation!)

‣ Care for ‣ Perfomance ratio

‣ Availibility

OVERALL TESTING STRATEGY

Provisional Acceptance Test (PAT): after this test has been positively passed, a “Provisional Acceptance Certificate” (PAC) is issued and the O&M phase is entered

Intermediate/Mid Test (MT): this test shall be carried out 12 months after PAC date;

Final Acceptance Test (FAT): this test shall be carried out 24 months after PAC date; after this test has

been positively passed, a “Final Acceptance Certificate” (FAC) is issued. 

Maintenance Stratgies

‣ Preventive Maintenance

‣ Clean panels

‣ Removal vegetation , bird drops , shading

‣ Check electrical connections ( thermal imaging) , loose connections , string current

‣ Kalibration : sensors , scada , monitoring system ( test data)

‣ Inverter functionality

‣ Corrective , reactive ,adhoc Maintenance

‣ „break and Fix“

‣ Condition based Maintenance ( proactive)

‣ Diagnose through Data mining ( Monitoring system with data archive)

O&M Model

‣ In House staff

‣ EPC Contractor

‣ Third party Provider‣ „best of the Breed“

Energy Loss Relative share in %

AC Sub systems 30

Inverters 35

DC Subsystems 15

Rest 20

Relative frequency Events

AC Sub systems 10

Inverters 60

DC Subsystems 15

Rest 15

System Failure domains

O&M Costs ( €/MWp/year Euros

Scheduled Maintenance/Cleaning 19,000

Unschedules Maintenance 1,500

Inverter Issues 7,500

O&M (without Insurance etc) 28,000

O&M Costs

Products of iPLON

EPC

Solar Infranet(iAT, iMT, Internet connectivity)

String Monitoring

Inverter Monitoring

Environ-mental Sensors

Monitoring

AC Power Metering

(Evc. Point)

Trans-former / Grid

connected comp.

Monitoring

System Engineering

Reviews Document.

Project Mgmt.

Services O&M

Comissioning

Training &

Workshops

Application and

Application Support

Challenges in India

‣ Cleaning of panels

‣ Maintenance and After Sales Services

‣ O&M

‣ Performance Guarantees (EPC)

Thank You!www.iplon.de

www.youtube.com/user/iPLONChannel

Benchmarking with real data

‣ Monitoring system

‣ Real Data

‣ Analysis of the data

iPLON „Experience“

Decentral Control Network ( tcp_IP and LONworks

Applications-Management Level

- Web based Portal- Total Life cycle Management- Visualization- Business logic

- Performance ratio- Remote Services- Database

-Automation Level- Datalogging- Alarming- Scheduling- Power reduction/ cos phi control- Management of devices

-Field Level- Sensors and Actuators

- Environmental sensors- Smart metering- Voltage , current, energy sensors ( AC +DC)

-Infrastructure Level- Internet connectivity (Automation to Management)

- Satelit , DSL,UMTS,GPRS- Routers , VPN, Reverse Tunneling, Firewalls

-- Field level connectivity- Wired ( TP , FO , PL)- Wireless ( Zigbee ??)

Technology-Management level

- Java, PHP, Python ,mysql

- Automation level- Deeply embedded systems- ARM9 / FPGA ,STM 32 , ATMEL- Board support package- Linux OS ( Drivers)- Rhapsody ( uml),C++, C , LUA script, python , shell

scripts- Protocols programming

- LONworks, Modbus , Inverter “KACO”- CAN ( partner : Penqutronics)

-- Network protocols- DHCP, PPP, UDP,TCP_IP, …..

-- Modem connections ,Mobile providers-Field Level

- Lonworks I/O- Power line I/O- Energy harvesting sensors

- Enocean- Zigbee

- Devices management ( Control Terminal)

Solar ProjectSolar

Project

Investor•Equity

Investor•Equity

Insurance Company•Policies

Management•Operation Contract

Management•Operation Contract

Service Company•O&M Contract

EPC Contrator(s)•EPC Contract

Utility•Power Purchase Agreement

Utility•Power Purchase Agreement

Developer•Project Rights

Lender•Loans