Are you aware that the energy produced over 25 years by PV modules can differ by as much as 50 percent, even though they have the same power rating? How do you know which module to select for your project? Choosing low-cost modules can give the impression that a PV project is at grid parity, but the ultimate metric for investors and consumers must be the long-term cost of energy production. Even so, developers cannot make the mistake of paying too much for the highest efficiency PV modules. In this webinar we will share our analysis of the PV module characteristics that determine Lifetime Energy Production™ and discuss the how the Principal Solar Institute PV Module Ratings can be used to select optimum solar panels for your project. In addition to direct cost-benefit analyses, the PSI PV Module ratings have been used by renewable energy investors in their utility scale solar due diligence process, and by Solarize Frederick County as a mechanism to document installers’ choice of solar system components. You should join us for a free webinar by Dan Bedell and Matthew Thompson of Principal Solar Institute to learn how the PSI PV Module Rating works and how it may be used in your solar project development.

1. Principal Solar Institute PV Module Ratings
to Evaluate Lifetime Energy Production
Dan Bedell
Sr. Director, Principal Solar Institute
EVP, Principal Solar Inc. May 8, 2014
Matthew A. Thompson, Ph.D.
Executive Director
Principal Solar Institute

2. Principal Solar Institute
Principal Solar Institute PV Module Ratings to
Evaluate Lifetime Energy Production
Dan Bedell
Sr. Director, Principal Solar Institute
EVP, Principal Solar, Inc.
Hosted by Rick Borry, Ph.D.
CTO, Principal Solar Institute
CTO, Principal Solar, Inc.
Matthew A. Thompson, Ph.D.
Executive Director
Principal Solar Institute

3. Matthew A. Thompson, Ph.D.
Executive Director, Principal Solar Institute
Matthew Thompson is a scientist with 23 years experience in semiconductor process development and
yield enhancement at Motorola and at Freescale Semiconductor.
At Motorola's Advanced Process Development Laboratory, he developed vertical gate oxidation processes
and equipment. In a collaborative research and development project that included Motorola and IBM, he
designed Synchrotron x-ray optics for deep submicron lithography, and supported x-ray mask design. The
project culminated with a successful fabrication of fully functional memory chips using x-ray lithography. In
another industry research project, Matthew worked with Motorola and Lucent Technologies to develop
200 mm mask manufacturing processes for a novel projection electron beam lithography technique. In
addition to these advanced lithography research projects, he developed computer algorithms for
Complimentary Phase Shift Masks, leading to volume manufacture of products with 50 nm gates using 248
nm imaging tools. At Freescale Semiconductor, he worked to improve profitability and performance by
development and deployment of Design for Manufacturability methodology.
Matthew earned a B.S. in Physics at Texas Tech University, and a Ph. D. in Physics at The University of Texas
at Austin. He holds seven patents in areas such as electronic design processing, x-ray mirror design, and
advanced e-beam lithography, optical photo mask design and microcircuit pre-failure detection.
Speaker Biography
3

4. Dan Bedell
Senior Director, Principal Solar Institute
EVP, Strategic and Corporate Development
Following a lifelong interest in renewable energy, Dan Bedell co-founded Capstone Solar, a think tank for
solar professionals to exchange ideas on policy and technology and a platform for peer to peer branding,
micro-networking and interactive solar webinars.
Dan previously worked on mergers and acquisitions in the global materials industry, integrating newly
acquired businesses into a standard corporate footprint at Lehigh Hanson, Inc. Prior to that, Dan was COO
and Director of Business Development for a Dallas-area construction company that was an early entrant
into the "green" building market and the rooftop solar installation market. In that capacity, he was an
advocate and evangelist for distributed solar generation in the state of Texas. He now brings that same
passion for the inevitable mainstream adoption of solar power to Principal Solar.
Dan holds his B.B.A. in Economics from the University of North Texas where he graduated cum laude and
spent a semester studying international finance in the UK.
Speaker Biography
4

5. Overview
 What is the difference between power and energy metrics,
and why does it matter?
 How is the Principal Solar Institute (PSI) PV Module Rating
based on Lifetime Energy ProductionTM
calculated?
 How can modules with the same nameplate wattage have PSI
Ratings that differ by 60%?
 What are the PSI Ratings of the PV market leaders?
5

6. Two different metrics for PV modules are both important:
•Price per watt ($/W) – Construction cost. Financing a solar project.
•Price per kilowatt hour ($/kWh) – Revenue. Energy is sold to consumers.
Power and Energy Metrics
Power: The rate at which work can be done.
Energy: The work that is done during a period of time.
Power metrics are prevalent in
articles and discussions about PV
modules.
The PSI PV Module Rating is a
module energy metric.
6

7. The Shelby GT500 has an engine
power of 410 kW (550 hp) and a tank
that holds 408 kWh of energy.
$135/kW $0.29/kWh
The Shelby is a bargain using the
$/W metric…
…but the Tesla costs much less to
operate in $/kWh.
The Tesla Model S has a motor power of
310 kW (416 hp) and a battery that holds
85 kWh of energy.
$0.12/kWh$300/kW
Driving Home the Point
The power of a car describes how quickly it can do work,
the energy of a tank of gas describes how far it can go.
7

8. The $/W metric is not directly
affected by module efficiency ...
 Land costs increase with area for utility-scale or community solar.
 Rooftop area constrains energy production for residential solar.
 Racking and cabling costs increase with area, so module efficiency has a
direct impact on Balance of System costs.
... but one module characteristic used
in the PSI Rating is “Area Efficiency.”
Even the most efficient PV modules only convert about 20% of sunlight energy...
photo: www.solairedirect.co.za
Efficiency is Important!
8

9. ... are used to calculate Lifetime Energy ProductionTM
and the PSI Rating.
Seven Essential Characteristics ...
Actual Tested
Maximum Power
vs. Advertised
Temperature
Coefficient at Maximum
Power
Low Light
Efficiency
Nominal
Operating Cell
Temperature
(NOCT)
Total Area
Efficiency
Negative
Power
Tolerance
Annual
Power
Reduction
Published Characteristics Affect
Lifetime Energy Production
9

10. 0
100
200
300
400
500
600
700
800
900
6:00
7:30
9:00
10:30
12:00
13:30
15:00
16:30
18:00
19:30
W/m2
Time of Day
Incident Irradiance
Measured
Calculated
0.0
5.0
10.0
15.0
20.0
25.0
30.0
35.0
4344 4394 4444 4494
AmbientTempC
Hour
Hourly Temperature
1st Week of July
We use cycles of sunlight and
temperature to calculate LEPTM
based
on how each module’s energy
production is affected by the seven
key characteristics.
The PSI Rating is then obtained by
taking the ratio of module-specific
LEP to the total available sunlight
energy.
PV Performance Model
10

11. 0.0
5.0
10.0
15.0
20.0
25.0
30.0
35.0
4344 4394 4444 4494
AmbientTempC
Hour
Hourly Temperature
1st Week of July
We use cycles of sunlight and
temperature to calculate LEPTM based on
how each module’s energy production is
affected by the seven key characteristics.
The PSI Rating is then calculated by
taking the ratio of module-specific
LEPTM to the total available sunlight
energy.
PV Performance Model
0
100
200
300
400
500
600
700
800
900
6:00
7:30
9:00
10:30
12:00
13:30
15:00
16:30
18:00
19:30
W/m2
Time of Day
Incident Irradiance
Measured
Calculated
11

12. Ratings Page at Principal Solar Institute
12

13. Each vertical bar in the chart above is the range of PSI Rating for one
manufacturer’s products. Ratings of about 13,000 modules from almost 400
manufacturers are listed in the chart above and on our website.
*GreenTech Media:
watts shipped.
*
GreenTech Media
identifies the top five
manufacturers ranked
by watts shipped in
2013. Not
surprisingly, most of
them have high PSI
PV Module Ratings.
PV Module Rating: Where
Are the Leaders?
13

14. Module Comparison
Nameplate
Power (W)
280
280
280
280
280
290
Manufacturer / Model No.
Ningbo / UL-280D
Trina Solar / TSM-280PA14
CSG PVTech / CSG280M2-36
Suntech / STP280-24/Vd
CentroSolar / SP7 280SW
Schott Solar / ASE-300-DGF/50-290
PSI
Rating
9.85
7.49
7.42
7.41
7.04
6.07
kW-h
Factor
162%
123%
122%
122%
116%
100%
kW-h
Factor
100%
76%
75%
75%
72%
61%
14

15. Manufacturer / Model Number
Nameplate
Power (W)
PSI
Rating
kW-h
Factor
Ningbo / UL-280D 280 9.85 1.62
Trina Solar / TSM-280PA14 280 7.49 1.23
CSG PVTech / CSG280M2-36 280 7.42 1.22
Suntech / STP280-24/Vd 280 7.41 1.22
CentroSolar / SP7 280SW 280 7.04 1.16
Schott Solar / ASE-300-DGF/50-290 290 6.07 1.00
All of these PV modules have about the same Nameplate Power, but a wide range of PSI Rating.
The PSI Rating is based on 25 year LEP, and the relative energy production is indicated in the last
column. The Schott PV would have to be available at about 60% of the Ningbo price to be more
cost-effective. (6.07 / 9.85 = 0.61)
Module Comparison
15

16. Manufacturer / Model Number *Price per Watt
Ningbo / UL-280D $0.65
Trina Solar / TSM-280PA14 $0.71
CSG PVTech / CSG280M2-36 $0.65
Suntech / STP280-24/Vd $0.60
CentroSolar / SP7 280SW $0.65
Schott Solar / ASE-300-DGF/50-290 $0.68
*Pricing data provided by Paula Mints, SPV Market Research
Module Comparison
16

17. The PSI Rating is:
– Unbiased and calculated based on published data
– Proportional to Lifetime Energy ProductionTM
– Aware of module efficiency
– Simple, with tabulated values
– Useful for cost-benefit analysis
– Ideal for documenting bids, financial discussions
– Available free on PSI website
Summary
17

18. Dan Bedell
Sr. Director, Principal Solar Institute
EVP, Principal Solar, Inc.
dan.bedell@principalsolar.com
Please enter your questions in the chat window
Matthew A. Thompson, Ph.D.
Executive Director
Principal Solar Institute
mt@principalsolar.com
Question and Answer…
www.principalsolarinstitute.org