S C H O O L O F A P P L I E D T E C H N O L O G YLaboratory of Energy and Photovoltaic Systems

Technological Educational Institute of Crete

Developing reliable photovoltaic

and outdoor high voltage systemsLEP

S

Photovoltaic Park

CENTER OF ENERGY AND PHOTOVOLTAIC SYSTEMSTEI OF CRETE

Laboratory of Energy and Photovoltaic Systems

Electrical Discharges Lab (EDL)Laboratory of Energy and

Photovoltaic Systems(LEPS)

Photovoltaic Park

CENTER OF ENERGY AND PHOTOVOLTAIC SYSTEMSTEI OF CRETE

Electrical Discharges Lab (EDL)

LEPS

TEI OF CRETE

Photovoltaic Park

CENTER OF ENERGY AND PHOTOVOLTAIC SYSTEMSTEI OF CRETE

Electrical Discharges Lab (EDL)

Photovoltaic Park

TEI OF CRETE

LEPS

TEI OF CRETEField of expertise:

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1. Solar Radiation LEP

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LEPS

TEI OF CRETEField of expertise:

1. Solar Radiation 2. Photovoltaic Generation PV module performance measurements,

• field testing bay – simultaneous operation of different technology PVs• degradation of PV performance

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CEPS

TEI OF CRETEField of expertise:

1. Solar Radiation 2. Photovoltaic Generation PV module performance measurements,

• field testing bay – simultaneous operation of different technology PVs• degradation of PV performance

• testing and measurement equipment developed in our lab

CEPS

TEI OF CRETEField of expertise:

1. Solar Radiation 2. Photovoltaic Generation PV module performance measurements, PV power modeling

LEPS

TEI OF CRETEField of expertise:

1. Solar Radiation 2. Photovoltaic Generation PV Panels testing and efficiency, PV Panels modeling Solar tracking

Novel Tracker (Two axis motion with a single motor)

A highly efficient novel Azimouthal heliotrope. Mayromatakis F. and Y. Franghiadakis Solar Energy. V82, Issue 4, April 2008, Pages 336-342

Modified Polar Tracker

CEPS

TEI OF CRETEField of expertise:

1. Solar Radiation 2. Photovoltaic Generation3. PV applications

LEPS

TEI OF CRETEField of expertise:

1. Solar Radiation 2. Photovoltaic Generation3. PV applications 4. Grid integration – high voltage networks PV generation forecasting, Operation in high voltage distribution networks Operation and reliability of high voltage distribution networks Outdoor high voltage insulation systems Implementation of composite HV insulation materials Field testing

LEPS

TEI OF CRETEPV generation in Crete:

The Power System Of Crete The largest isolated power system in Greece Load factor

LEPS

TEI OF CRETEPV generation in Crete:

STEAM TUR-BINES 20%

GAS TUR-BINES 32%

COMBINED CYCLE 12%

DIESEL GEN-ERA-TORS 14%

WIND GEN-ERA-TION 16%

PV GENERATION 6%

The Power System Of Crete The largest isolated power system in Greece Load factor Installed generation

Total installed power generation 1091MW

Wind Farms 180MW PV Generation 70MW

63MW Field PV Parks (800X ≈80kW)7MW roof installed PV generation

TEI OF CRETEPV generation in Crete:

The Power System Of Crete The largest isolated power system in Greece Load factor Installed generation

Total installed power generation 1091MW

Wind Farms 180MW PV Generation 70MW

63MW Field PV Parks (800X ≈80kW)7MW roof installed PV generation

Small PV generation installations

Connected to the 20kV or 400V network

Distributed in Crete

STEAM

TURBINE

S 20%

GAS TURBINE

S 32%

COMBINE

D CY-CLE 12%

DIESEL

GEN-ERA-TORS 14%

WIND

GEN-ERA-TION 16%

PV GENERATION 6%

LEPS

TEI OF CRETEPV generation in Crete:

The Power System Of Crete The largest isolated power system in Greece Load factor Installed generation Annual peak load during the summer Daily two peak loads at 12:00 – 13:30 and 17:00-21:00

LEPS

LEPS

TEI OF CRETEPV generation in Crete:

First concern: generation forecasting

PV generation (sunny days)

Tracker

FixedDuring the summer: The period of optimum performance

coincides with the period of maximum demand,

The daily peak load coincides with the peak generation of PVs,

Considering that cloudy days are not often during the summer, PV generation can be predictable for the system operator,

Small variations are usually eliminated due to the distribution of PV installations,

Benefits for the network But There is a strong dependence of the PV

generation reliability to the network reliability

The system operators demands reliable estimation tools for the PV generation

LEPS

TEI OF CRETEPV generation in Crete:

First concern: generation forecasting

PV generation (cloudy days)

Cloudy

SunnyIn the case of cloudy days: During cloudy days there are large

variations on the PV generation of each installation,

In a total these variations are eliminated by the geographical dispersion of the PV installations

LEPS

TEI OF CRETEPV generation in Crete:

6:00 8:24 10:48 13:12 15:36 18:00 20:240

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CHANIA

CHANIA PV generation 18 - 09 - 2012

LEPS

TEI OF CRETEPV generation in Crete:

6:00 8:24 10:48 13:12 15:36 18:00 20:240

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RETHYMNO

RETHYMNO PV generation 18 - 09 - 2012

LEPS

TEI OF CRETEPV generation in Crete:

6:00 8:24 10:48 13:12 15:36 18:00 20:240

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IRAKLION

IRAKLIONPV generation 18 - 09 - 2012

LEPS

TEI OF CRETEPV generation in Crete:

6:00 8:24 10:48 13:12 15:36 18:00 20:240

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LASITHI

LASITHI PV generation 18 - 09 - 2012

CEPS

TEI OF CRETEPV generation in Crete:

6:00 8:24 10:48 13:12 15:36 18:00 20:240

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RETHYMNO

IRAKLION

LASITHI

PV generation 18 - 09 - 2012

LEPS

TEI OF CRETEPV generation in Crete:

6:00 8:24 10:48 13:12 15:36 18:00 20:240

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CHANIA

RETHYMNO

IRAKLION

LASITHI

AVERAGE

PV generation 18 - 09 – 2012

In an average

How can we reliably operate a fleet of PV generation units and further predict the short term and long term generation.

LEPS

TEI OF CRETEPV generation in Crete:

1. The total PV generation variation is improved in quality as more PV plants are connected, Is this useful for the system operator? It is not enough, more information is required 2. There is a large number of generation points to monitor Determine criteria to select a representative group of generation points to be

monitored, 3. Are we interested only for the PV generation?

No, for example voltage stability of 20kV lines is also a critical point 4. Is the network influencing the PV generation Certainly, the HV network becomes a critical component of the equivalent “PV Generator” . Transmission line outages are more frequent as the HV network

of interest geographically expands, thus can alter the “PV Generator” reliability.5. Primary cause of transmission line outages in Crete is a phenomenon called

“Pollution of HV insulators”

LEPS

TEI OF CRETEOutdoor HV Systems:

Pollution of High Voltage Insulators Development of surface conductivity on the surface of High Voltage

insulators, Result of the water dissolution of sea salt deposition, Capable of resulting to the total loss of insulation. Primary cause of power outages in Crete

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LEPS

TEI OF CRETEOutdoor HV Systems:

Pollution of High Voltage Insulators Development of surface conductivity on the surface of High Voltage

insulators, Result of the water dissolution of sea salt deposition, Capable of resulting to the total loss of insulation. Primary cause of power outages in Crete

Present during the summer Fortunately appears during the night

LEPS

TEI OF CRETEOutdoor HV Systems:

Pollution of High Voltage Insulators Development of surface conductivity on the surface of High Voltage

insulators, Result of the water dissolution of sea salt deposition, Capable of resulting to the total loss of insulation. Primary cause of power outages in Crete

LEPS

TEI OF CRETEOutdoor HV Systems:

Pollution of High Voltage InsulatorsPollution of HV insulators cannot have a direct influence on PV generation, however in Crete has considerable impact on the reliability of the HV network.Is there a solution? The use of composite hydrophobic materials, insulators or coatings

CEPS

TEI OF CRETEOutdoor HV Systems:

Pollution of High Voltage InsulatorsPollution of HV insulators cannot have a direct influence on PV generation, however in Crete has considerable impact on the reliability of the HV network.Is there a solution? The use of composite hydrophobic materials, insulators or coatings

LEPS

TEI OF CRETEOutdoor HV Systems:

Pollution of High Voltage InsulatorsTalos Testing Station (www.talos-ts.com)

T.E.I. of Crete P.P.C. S.A.University of

Patras

At Linoperamata Crete

LEPS

TEI OF CRETEOutdoor HV Systems:

Pollution of High Voltage InsulatorsComposite materials have been implemented in the 150kV network of Crete, for more than 10 yearsOutages due to pollution have been eliminated

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LEPS

TEI OF CRETEOutdoor HV Systems:

Pollution of High Voltage InsulatorsComposite materials have been implemented in the 150kV network of Crete, for more than 10 yearsOutages due to pollution have been eliminated It is necessary to incorporate this solution to the 20kV network

20KV TALOS TESTING BAY

LEPS

TEI OF CRETEIn conclusion:

1. PV generation is a very promising technology for power generation and Crete is an ideal place to be implemented2. CEPS is formed in an effort to bring together people working in the fields of RES and Power Systems, aiming to optimize the integration of PV

generation in Power High Voltage Distribution Systems3. Crete is today the best possible case study for RES and distributed generation

systems.4. Full scale grid optimization is required to achieve a reliable operation of a

distributed “PV generator “ 5. High voltage insulation is a critical parameter for the reliability of high voltage

distribution system. 6. The improvement achieved by the use of composite insulation in HV networks has been proved in the environment of Crete