PV Plant Design

OptimizationLearning from India's 2GW Installations

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Performance Data

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• For this presentation

• Sample of 50 plants

operational for at least

one year in Gujarat

• 28 with c-Si and 22 Thin

Film

This is how the data

tables look like

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?

CUF: What do you

expect?www.reach-solar.com

?

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2

0

2

3 3

6

14

16

1

3

12% to 13% 13.1% to 14% 14.1% to 15% 15.1% to 16% 16.1% to 17% 17.1% to 18% 18.1% to 19% 19.1% to 20% 20.1% to 21% Above 21%

Frequency Distribution CUF Values

Highest CUF 21.3%

Lowest CUF 12.2%

The Difference:

Absolute: 9.1% | Factor: 1.75

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60.00%

92.00%

94.00%

40%

8%

6%

Top Performers vs. All Others

2

0

23 3

6

14

16

1

3

12% to 13% 13.1% to 14% 14.1% to 15% 15.1% to 16% 16.1% to 17% 17.1% to 18% 18.1% to 19% 19.1% to 20% 20.1% to 21% Above 21%

Frequency Distribution CUF Values

Is this problem specific

to India?www.reach-solar.com

?

No, it is not!“Nevertheless, the PV systems evaluable per region showed

significant deviations in their respective yields. Although located

in a similar environment, the yield variation in some regions was

up to 20 %. Assessment of the quartiles revealed 75 % of the

plants underperforming compared to the top performing

plants. Another 5 % were included in the group of outliers

due to their overall yield being too low for this study. The

significance test proves that, due to the sufficiently high number

of evaluable PV plants, the statistical results of our study reflect

the actual yields of the PV systems to a high degree.”

- Source: Survey on yield of photovoltaic plants 2012 in Germany

by Meteocontrol (Prof. Dr. Henirk te Heesen et al.

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Is it because of the

panels?www.reach-solar.com

?

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1 1 1 1

7

9

1 11 1

2

3

5

7 7

0

2

12% to 13% 13.1% to 14% 14.1% to 15% 15.1% to 16% 16.1% to 17% 17.1% to 18% 18.1% to 19% 19.1% to 20% 20.1% to 21% Above 21%

CUF vs. Technology

Thin Film c-Si

Note:

There are 28 c-Si, but

only 22 Thin Film

installations in this

sample!

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12% to 13% 13.1% to 14% 14.1% to 15% 15.1% to 16% 16.1% to 17% 17.1% to 18% 18.1% to 19% 19.1% to 20% 20.1% to 21% Above 21%

CUF vs. Technology II

Thin Film c-Si

Bottom line:

There are very good and not so good

performing plants either with Thin Film

or c-Si!

Is it because of the

size?www.reach-solar.com

?

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Bottom line:

Do larger / smaller plants perform better?

One thing is for sure: The sample of 50

plants is too small to give an answer.

15.40

17.55

11.73 11.67 11.67

14.59 14.14

10.22

6.67

12% to 13% 13.1% to 14% 14.1% to 15% 15.1% to 16% 16.1% to 17% 17.1% to 18% 18.1% to 19% 19.1% to 20% 20.1% to 21% Above 21%

CUF vs. Average Installed Capacity

Average Installed Capacity

So what can we learn

from this?www.reach-solar.com

?

A Skeptical Thesis

• We do not have enough information, because

• Generation Data and CUF do not provide the

right or enough insights

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Why have we done this

exercise?www.reach-solar.com

?

Reasons

• #1: To understand better the limitations of CUF and

generation data

• #2: To build awareness that there might be a

problem & that there is room for improvement

• #3: Not specific to India – happens also in Germany

/ Europe so it affects the whole industry

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CUF: What goes into the

equation…

• Units generated

• Installed Capacity

• Time (e.g. 1 year)

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hkWCapacityInstalled

kWhMeasuredEnergyCUF

8760)(

)(

CUF: What goes not into

the equation…

• Ambient

Temperature

• Panel Temperature

• Irradiation at Project

Site

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• Grid related aspects

• Availability

• Frequency

PR: A Different Approach

• Instead of asking:

What was achieved

without asking

about the frame-

conditions and

circumstances

• Ask:

What could have

been achieved

considering all the

frame conditions?

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77.58%81.54%

78.90% 78.63%76.00% 75.90%

72.03% 74.42% 76.39% 78.32%72.80% 70.60%

4%10%

14%18%

25%21% 19% 21% 19%

9%4% 3%

January February March April May June July August September October November December

Comparison of CUF and PR for a PV System in Germany(2012)

Performance Ratio [%] CUF [%]

Takeaways

• #1: Great components do not automatically lead to

high performing plants

• #2: Design has a huge impact (but not only

electrical design!)

• #3: CUF is a good tool but will not provide the

complete picture

• #4: PR is also a tool for quality management

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DESIGN

CHALLENGES

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Design for Reliabilitywww.reach-solar.com

Component Capacity Nos Installed Plant

Capacity Lost

Chance of

Detection

1 Panel 250Wp 4000 0.025% “0”

1 String 5kWp 200 0.5% Not very likely

1 SCB 50kWp 20 5% Possible

1 Inverter 500kW 2 50% Likely

1 Transformer 1000kW 1 100% Most likely

*1MW plant – not a real application; simplified for illustration

“Classical Approach”

•#1: Panels

•#2: Inverter

•#3: Temperature

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“Classical Approach”

•#1: Panels

•#2: Inverter

•#3: Temperature Price

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Performance of Panelswww.reach-solar.com

80%

82%

84%

86%

88%

90%

92%

94%

96%

98%

100%

0 5 10 15 20 25

Min. Performance and Typical Performance of c-Si Panels vs. Time in Operation (Aging Process)

Min. Performance Typical Performance

Temperature

De-Rating

Performance of Inverterwww.reach-solar.com

0

20

40

60

80

100

120

0 10 20 30 40 50 60 70

Sta

nd

ard

ized

Ou

tpu

t P

ow

er

Ambient Temperature

Simplified Output Power vs. Ambient Temperature

Is focusing on Panels

and Inverters enough?www.reach-solar.com

Drainage & Civil Workswww.reach-solar.com

SCBswww.reach-solar.com

SCB: Mission Critical Componentwww.reach-solar.com

Component Capacity Nos Installed Plant

Capacity Lost

Chance of

Detection

1 Panel 250Wp 4000 0.025% “0”

1 String 5kWp 200 0.5% Not very likely

1 SCB 50kWp 20 5% Possible

1 Inverter 500kW 2 50% Likely

1 Transformer 1000kW 1 100% Most likely

*1MW plant – not a real application; simplified for illustration

Transformer Monitoringwww.reach-solar.com

…also at Plant

Level?www.reach-solar.com

Transformer: Mission Critical

Componentwww.reach-solar.com

Component Capacity Nos Installed Plant

Capacity Lost

Chance of

Detection

1 Panel 250Wp 4000 0.025% “0”

1 String 5kWp 200 0.5% Not very likely

1 SCB 50kWp 20 5% Possible

1 Inverter 500kW 2 50% Likely

1 Transformer 1000kW 1 100% Most likely

*1MW plant – not a real application; simplified for illustration

Mounting Structureswww.reach-solar.com

Mounting Structureswww.reach-solar.com

Mounting Structures: Mission Critical

Componentwww.reach-solar.com

Component Capacity Nos Installed Plant

Capacity Lost

Chance of

Detection

1 Panel 250Wp 4000 0.025% “0”

1 String 5kWp 200 0.5% Not very likely

1 SCB 50kWp 20 5% Possible

1 Inverter 500kW 2 50% Likely

1 Transformer 1000kW 1 100% Most likely

*1MW plant – not a real application; simplified for illustration

No, it is not specific to India!www.reach-solar.com

Mounting Structureswww.reach-solar.com

Conclusion• Plant Efficiency

• EPCs and Owners Engineers – educate your clients about plant efficiency (PR vs. CUF)

• Quality Control• Install and use a SCADA system to monitor and document

the plant performance

• System Deployment• Deploy a system – focus on all design aspects (not only

electrical, but also civil)

• Share• Share your generation and performance data to set a

benchmark

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80 / 20

Top Performing

Plants Now

Top Performing

Plants in Future

Contact Us

REACH Solar Consulting P Ltd.

S3 Team Business Center

98 V M Street, Mylapore

Chennai 600004

India

madhavan@reach-solar.com

c/o CHROSIS UG

Hallerstrasse, 27

74549 Wolpertshausen

Germany

sebastian@reach-solar.com

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