Gay E. Canough

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Gay E. Canough
ETM Solar Works
Explore, enjoy and protect
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Learning How the Universe Works
Particle Physics and You
Simple capacitor Bank is first stage Particle
accelerator
Fermilab Particle Accelerator
Proton Splatter
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From The Professional Pest by G. Canough Rule
1 Determination and Persistence Will Get You
Anywhere!
In this case, To the Moon!
The Lunar Prospector
As designed by ETM And SSI
As built by Lockheed
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Space Solar Power 24 hours per day!
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• Use Renewable Energy because
• You care about the future
• Earth is our one and only home
• You want to grow your own electricity
• Sources of fossil fuel are finite
• Increasing CO2 leads to climate change
• Distributed generation more robust than
  centralized

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CO2
Data from Antarctic Ice Core shows CO2 for past
400,000 years
Scientific American, March 2004
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500 MW of PV would have prevented this. It would
have cost 3 billion. Cost of power outage to
business 8 billion! --- R. Perez
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USA stuck on fossil fuel
Source Solarbuzz
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Electricity Farming in Germany
Village Solar Power Plant, 10 MW
Bavaria Solarpark in Muehlhausen, Guenching, and
Minihof
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Did you know that The entire country of Germany
is NORTH of 46 degrees latitude. Munich 48
degrees N While Syracuse is at 43 degrees NORTH
latitude. Germany has 837 Megawatts of PV
installed (as of Dec. 2005)
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Solar Energy in New York
New York 2.6 MW installed
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News from Solarbuzz World solar photovoltaic
(PV) market installations reached a record high
of 1,460 Megawatts (MW) in 2005, representing
annual growth of 34. Cumulative installed
solar PV electricity generating capacity expanded
by 39 in 2005 and now exceeds 5 Gigawatts
worldwide. Investment in new plant to
manufacture solar cells exceeded 1 billion in
2005.
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The Solar Resource
The Definition of Full Sun is 1000 Watts/square
meter Under these conditions    In 1 hour 1
square meter of the Earths surface
intercepts 1
Kilowatt-hour of solar energy.  
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Units
A Kilowatt Is a Unit of Power A Kilowatt-hour is
a Unit of Energy Power is momentary effort
required to do something. Its like the strength
needed to lift that battery. Energy is Power x
Time. Its like the amount of pizza required to
keep a solar installer lifting batteries for an
hour.
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1 full-sun-hour is the same as 1 kWh/square
meter because 1 kW/m2 falling on a square meter
for one hour is 1 kWh
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June 21
North
West
Dec 21
PV modules
East
South
Path of the Sun
Face your PV South, DO NOT SHADE!
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30 Years of Data Does Not Lie!
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3 of the State of New Yorks land area is
covered with buildings and parking lots.
If we covered just 1/3 of these buildings and
parking lots with photovoltaics, we could power
the entire state!
From Dr. R. Perez, SUNY Albany
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30 yr average kWh per sq. meter per year in San
Diego, Ca.. 2044 Phoenix, Az
.2336 Syracuse, NY ..1533 Binghamton, NY
.1496 New York City 1642 Seattle, Wa
..1387
Seattle gets 60 of the amount of sun that
Phoenix gets. Binghamton gets 73 of the amount
of sun that San Diego gets. This means we need a
LARGER AREA of photovoltaics in Binghamton than
they do in San Diego to make the same amount of
KILOWATT-HOURS.
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New York City, Long Island and NJ get 70 of the
amount of sun Phoenix gets
Summer peaking load (air conditioning) high
utility rates lots of sun in the summer dire
need of grid support some of the best places in
the USA for Solar power!
From Dr. R. Perez
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The amount of energy you can collect depends
on           Sun-angle         Atmospheric
absorption         Collector tilt angle        
Collector asimuthal orientation
(East-West)         Collector efficiency        
Power conversion efficiency (DC to AC)        
Wiring losses.
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By far, the biggest limit on how much useful
energy you get is collector efficiency.   For
photovoltaics, the energy not converted to
electricity is about 85!   The next largest loss
is in the inverter, at around 10 to 15.   While
much worry has gone into other items, they reduce
the overall system efficiency by only a few
percent. Such as   Collectors not pointing solar
south off by /- 30 degrees leads to about 2
loss.   Wiring loss is usually 2 to 5.   Even
putting the collectors flat instead of tilted
reduces the overall energy collection efficiency
by about 10 in the Northeast   Facing the
collectors due West or due East reduces the
overall energy collected by about 14.   So while
you should always look for ways to optimize the
systems efficiency, be aware that it may be less
expensive, more aesthetic or more convenient to
sacrifice some efficiency.
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Calculating System Performance
  The National Renewable Energy Laboratory
provides data on solar irradiance that allows you
to calculate system performance in the city in
which you are installing. Look online at
www.nrel.gov for Documents and Data Renewable
Resource Data Center Solar Radiation Resource
Information 30 Yr. (1961-1990) Avg. of
Monthly Solar Radiation Alphabetical Order
by State City Instructions Pick a city, open
the database, and save as a text file (.txt) Open
the saved file in EXCEL or similar
spreadsheet Save as a tab delimited file
Select delimited file type / Select Tab and
Comma delimiters Save delimited file in EXCEL
or similar spreadsheet
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www.nrel.gov
30 years of data does not lie!
SOLAR RADIATION FOR FLAT-PLATE COLLECTORS FACING
SOUTH AT A FIXED-TILT (kWh/m2/day), Percentage
Uncertainty 9
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Calculating the system performance
Output in kWh PV size in kW x efficiency x
full-sun-hours
12 Sharp 208 modules 2.496 kW System efficiency
is about 75 Full-sun-hours in Albany
1569/year Output 2.496 x 1569 x 0.75 2937
kWh
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Whats the efficiency?
Inverter output power STC Array power (watts)
STC 1000 W/2 and 25 C x mismatch and dust
factor (0.9) x Array temperature factor (0.885
at 46 C) x wiring efficiency (0.97) x
inverter efficiency (0.94)
Thats STC Array power x 0.9 x 0.885 x 0.97 x
0.94 That is STC Array power x 0.72
These numbers come from the Florida Solar Energy
Center Experience base
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Or you can calculate the monthly performance
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So, can humans be at least as smart as trees and
shrubs and
Harness the Power of the Sun ?
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Stepping up to solar power
Solar electricity (photovoltaics) And wind power
Active solar heating (solar hot water)
Passive solar design
Energy efficiency
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Scotty Says Reduce Your Load, Captain Kirk!
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Energy Efficiency Saves Big Bucks
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Visit these web-sites to find out how
www.energystar.gov
www.getenergysmart.org
US Green Building Council
www.usgbc.org
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Gas prices got you down? Get a hybrid
gas-electric car.
50 mpg Oh What a Feeling!
Gays Toyota Prius
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House with solar hot water heaters
Searsburg Road Trumansburg, NY
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Solar Hot Water System
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Gay E. Canough
ETM Solar Works
What is Photovoltaics?
module
cell
frame
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Photovoltaic Array
8.66 ft wide
24.2 long
module
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Photo is Greek for Light Voltaic is defined as
electricity produced by chemical action. Its root
is Volts, named for Allesandro Volta the inventor
of the battery. The battery was the first means
of generating electricity.   Photovoltaics (PV)
literally means Electricity from Light.
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Most commercially available PV is made of
Silicon. Silicon solar cells come in three main
varieties Single-crystal silicon, 17 to 22
efficient Poly-crystal silicon, 15
efficient Amorphous silicon, 5 to 7 efficient
New kinds of PV Copper-Indium-Diselenide Cadmium-
Telluride Dye Titanium-Dioxide Pentacene Prism
concentrating PV modules
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Miracle of the Semiconductor
An electric field is created by virtue of the
material alone. When a photon of light dislodges
an electron at the junction, it experiences a
FORCE. Force leads to motion. Moving
electrons are a CURRENT. The solar cell is about
250 microns thick.
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The solar cell is the basic unit from which a PV
module is made. A solar cell produces 0.5 V and
up to 7 A, depending on the type of cell.   A
PV module is one series string of cells laminated
to a backing material (fiberglass or glass),
sealed in weatherproof plastic (usually a type of
vinyl that wont discolor in the sun), glass
cover, and often an aluminum frame.   A bunch of
modules on a rack is called a solar array or PV
array.
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How PV is made
Silicon crystal boule
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Growing a Silicon Crystal
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• P-type
• 1) Boron dopant
• 2) About 250 microns thick
• N-type
• Phosphorous dopant
• About 0.3 microns thick

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Presto! Light To Electricity!
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Whats SERIES?
Batteries in Series to -
1.5 V 1.5 V 3 V
VOLTAGE ADDS
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Whats SERIES?
0.5 V 0.5 V 1 V
Solar Cells in Series to -
VOLTAGE ADDS
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• Characteristics of series strings
• One path for current flow
• Putting PV modules in series increases system
  voltage

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Kyocera 167
The voltage changes with temperature The current
changes with irradiance
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Calculating Voltage Change with Temperature
V (at Temp) V (at STC) Temp coeff x (T of
interest 25 C) Example The Kyocera 167
module has a temperature coefficient of -0.112
V/C Thats volts per degree C. It is negative
because the voltage gets HIGHER as the
temperature gets LOWER. The open circuit voltage
is 28.9 V at STC (1000 W/sq. m. , 25 C).
At 20 C (-4 F) Voc (at -20) 28.9
-0.112 x (-20-25) 28.9 -0.112
x -45) 28.9 5.04
33.94 V
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Stand-alone photovoltaics
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Off the Grid in Upstate NY
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The Power Shed
900 W
Inverter, charge control And battery bank in shed
To house
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Really, Really Remote
Cathead Mountain Adirondacks
Jan 1998
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Youll need one of these pesky things For
off-grid solar power
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Dont like batteries? Try
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The Lehman Alternative Community School Goes
Solar!
Ithaca, NY
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Albany County Hockey Facility Solar Power Keeps
Ice Cold! 40 kW
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Sidney Library 10 kW
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Tompkins County Public Library in Ithaca NY
Goes solar 186 kW
20000 sq.ft. of PV
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The Site Visit
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The Site Visit
Find a place where there is no shade from 8 A to
5 P. No shade is guaranteed when the object is
2 to 3 times as far away as it is tall. The
roof is the best place unless it is shaded. Try
to keep ground-mounts within 100 feet of cabin
Shade problem
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Solar Access
Photovoltaic system performance will be greatly
reduced if even a small part of the array is
shaded
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The Solar Pathfinder shows you what structures or
trees shade the Area you are considering
Use the Solar Pathfinder at all 4 corners of
site of proposed array
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Solar Pathfinder Chart
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Pathfinder reading
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Figuring out lost Sun-hours due to shading

• Compute hours lost for each month
• Add them up
• Subtract from yearly total

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So now we would have to use the reduced number of
Hours of Full Sun in our performance formula
Hours of Full Sun x system efficiency x PV size
in kW kWh generated
Example 1425 Hours of Full Sun x 0.75 efficiency
x 2.4 kW 2565 kWh Instead of 2825 kWh with no
shade.
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The Site Visit
Site Measurements
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The Site Visit
Old shingles 5 per row New Shingles 5.5 per
row
Measure roof up-slope
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The Site Visit
Up-slope dimension cross check measure slope, do
trig
hypotenuse
angle
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Trig review
Tangent A opposite / adjacent Sine A opposite
/ hypotenuse Cosine A adjacent /
hypotenuse Angle B Angle A (Rule of Similar
Angles)
B
Hypotenuse (H)
Opposite (Y)
Angle A
Adjacent (X)
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The Site Visit
Look in the attic, measure rafter spacing and size
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The Site Visit
What kind of roof support Is there?
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The Site Visit
Where is the meter? The incoming utility
lines? (If any)
Plot Plan
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If you have to do tilt-ups on roof, space the
rows so one does not shade another.
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Tangent(18) opposite over adjacent Y/X
24/X Solve for d X 24/tan(18)
73.46 6 feet
If you are unfamiliar with algebra, make a scale
drawing instead. You will need a ruler,
protractor and calculator to do this.
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Sloped arrays require more space
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Tilt-up on NW roof to face PV South
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If you do multiple pole-mounts, place poles so
one PV array does not shade the other
Sun-angle
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Pole-top PV mount
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The Site Visit
Choose a place for the battery bank. Batteries
like to be warm The inverter must be within 20
ft of the battery
Measure the distance from that spot to the
battery location
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Choose a place for the inverter and disconnects
vent
Power panel
Battery box
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The Site Visit
Record the size and type of cabin circuit box
(load center) If there is no circuit box, make a
note of that and record the number of circuits
(or potential number)
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PV Mounting Systems
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PV on aluminum rack, bolted to rafters will
withstand a hurricane!
Sidney, NY
Bethpage, NY
Rochester, NY
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Ground-mounts
Pole-top mount
Solar deck
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Clamp on metal roof seam, no penetrations
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NY Department of Transportation goes solar. 40 kW
in Kirkwood NY
Powerlight PV system generates electricity,
protects roof and adds insulation to roof.
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60,000 sq.ft. PV array, 612 kW
Just in case you are still thinking that solar
power cant serve a large load heres over ½ a
megawatt in Farmingdale NY!
Photo source Powerlight
Every 100,000 square feet of roof space can
generate 1 megawatt with PV on it.
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2.5 kW solar array, Where?
UniSolar PV Shingles in Speonk, NY
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Solar Electric Roof with Atlantis SunSlates 50
year warranty!
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Dont like panels? Try photovoltaic roofing!
Unisolar PV Laminates stick to Galvalume metal
roof.
7 kW on Green Cinderella in Brooklyn NY
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Atlantis Energy Day-lighting PV Light AND
electricity for your building!
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PV System Design Considerations
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How much photovoltaics do YOU need for your
house? Your Load in KILOWATT-HOURS per
year Divided by Hours of Full Sun x system
efficiency   If your yearly load is 5000 kWh, the
sun in Ithaca is 1496 Hours of Full Sun per year
and the system efficiency is 75 (typical) then
the PV system you will need to run it is 5000/
(1496 x 0.75) 4.46 kW Photovoltaic System South
roof, NO shade 4.46 kW requires about 356 square
feet of roof. For irradiance data in your area,
visit www.nrel.gov
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How Many Modules?
Step 1) Select an inverter and module Step 2)
determine how many modules you need in SERIES to
get the system voltage required by inverter This
is often referred to as a series string. Step
3) multiply modules per series string by power
Rating per module Step 4) divide total system
power desired by power of each string Step 5)
decide how many series strings matches inverter
Power rating
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What are my module choices?
Sharp 165,175, 185, 140, 167, 123, 208 W Sharp
70s are triangular GE/Astropower 165, 110
W Kyocera 120 W, 167 Sanyo 200 W Mitsubishi
110 BP 160 W Unisolar roofing Atlantis
roofing Isofoton 165 W Sunwize 120 W MORE
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What are my Inverter choices?

• Inverters for Stand-alone
• Xantrex DR, SW
• Prowatt
• Hundreds of others!
• Inverters for Net Metering
• Xantrex GT3
• SMA 2500, 1800 W, 6000 W
• Sharp Sun Vista 3500 W
• Fronius 2 kW, 3 kW, 4 kW, 5.1 kW
• Solectria 13 kW
• PV Power, Outback, Magnetek and more!
• Inverters that can do both
• Xantrex SW
• Beacon M5

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Inverters
  In the old days, people using solar energy
had to use DC appliances. While some DC
appliances are still popular in off-grid homes,
the average on-grid home is wired for AC.
  Inverters convert DC to AC. Modern inverters
are very efficient 85 to 95 is typical.   The
newest innovation in inverters are models that
can work in synchrony with utility power. These
inverters have sine-wave output, are able to
synchronize their output with the utility wave
form, and have special safety features to prevent
back feeding the grid if utility power is down.
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SMA 2500 Sunny Boy
Sharp 3.5 kW inverter
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No Islanding
The utility grid is a very well controlled
entity. It has to be this way to prevent
electrical chaos. For example, if the frequency
of the utility power varies, then power is lost
due to out of phase waves canceling each other
out! Thus, the frequency standard for utilities
is often as small as /- 0.5 Hz. When the
frequency drifts even 0.2 Hz, the utility starts
shedding loads. The voltage is more variable,
going from 108 to 132 V.   Inverters have to be
able to follow the utility wave form and shut off
under a variety of circumstances. The inverter
must be able to shut down, even when the utility
power is down but other inverters or inductive
loads are on in the local neighborhood.
Otherwise, the power back feeding into the grid
could create a dangerous condition called
ISLANDING.
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Certified Devices
SMA 6000
Fronius
Beacon M5
Xantrex SW
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Follow the Interconnection RulesFollow the
National Electrical Code
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What if the customer wants backup power?
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Pole-mounted grid-tie with battery backup in
Saratoga NY
10 kW
Power panel
Battery bank
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Series String Sizing
Sunny Boy 2500 inverter
Sharp 208 module
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• Find the maximum number in series allowed
• 600 V/(Voc x 1.25)
• 600 /(36.1 x 1.25)
• 13.29 modules, or 13 as the maximum

This ensures you never exceed 600 V on the open
circuit
2) Find the minimum number in series 234
V/(Vmp x 0.75) 234/(28.5 x 0.75)
10.94 or at least 11 modules as minimum
This ensures you stay in the peak power tracking
regime when the modules are hot
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You can choose 11, 12 or 13 Sharp 208 modules in
series. Now the final choice depends on things
like available space, orientation and budget. To
get the manufacturers recommended string sizing,
go to their web-page. For SMA, that is
www.sma-america.com
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Wiring diagram
SMA inverter
240 Vac
DC disconnect
AC disconnect
Load center
12 modules in series
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Fancier wiring diagram, 30 kW
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Syracuse NY
Look at all that roof space crying out for
photovoltaics!
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Google Earth your Town to Prospect for Roof Space
The MOST, Syracuse, NY
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PV Cost Considerations
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Cost of Solar Electricity
SUV Life expectancy 8 years
4 kW Solar Electric System Life expectancy 35
years
These things both cost 40,000
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How much photovoltaics do YOU need for your
building? Your Load in KILOWATT-HOURS per
year Divided by Hours of Full Sun x system
efficiency   If your yearly load is 5000 kWh, the
sun in Ithaca is 1496 Hours of Full Sun per year
and the system efficiency is 75 (typical) then
the PV system you will need to run it is 5000/
(1496 x 0.75) 4.46 kW Photovoltaic System South
roof, NO shade 4.46 kW requires about 356 square
feet of roof. For irradiance data in your area,
visit www.nrel.gov
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Cost of Solar Electricity
The 4.46 kW PV system will cost around 44,600
(or 10/Watt). But what you pay is 44600
-17,840 ---------- 26760 You can finance
up to 20,000 with the Energy Smart Loan Then at
tax time, you get up to 5000 NYS CREDIT and up
to 2000 Federal tax credit So the cost is
ultimately less than 20,000

• Words to the Wise
• Larger systems cost less per Watt.
• Solar roofing costs more per Watt than panels.
• Battery backup adds 7000 to the cost.
• Roof mounts are less expensive than
  ground-mounts
• Some contractors are less expensive than others
• Some contractors are better qualified than others

So it is comparable to buying a new car.
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New York Encourages Solar Power
You get 4/W discount on solar electric
systems Up to 5000 tax credit Low interest
Energy Smart Loan
Even the federal government is beginning to feel
the sunshine
In 2006 and 2007, you get up to 2000 federal tax
credit on solar energy systems
For more incentive info see www.dsireusa.org
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Economic Factoids

• For 50 kW roof-top PV System in Westchester
  County on
• south-facing low-slope roof
• PV System cost before incentive 425,000.00
• NYSERDA Incentive -200,000.00
• State Tax credit 5000
• Federal Tax credit 2000
• Final PV system cost 218,000.00
• Utility Con Ed
• kWh cost 18 cents
• Assumed rate increase over time 5 per year on
  average.
• Low Interest Loan at 4, 10 year term
• Cost per kWh of PV 12 cents
• Time to positive cash flow 13 years

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Economic Factoids
Yearly loan cost
What you would have paid Con Ed
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Economic Factoids

• What you will have paid Con Ed in 30 years, if
  you dont go solar 784,277.21
• The average return on investment for PV system is
  6.39 (first ten years)
• The decades-long average ROI for traditional
  investments such as stocks is 8
• The Hoover Dam took 50 years to pay for itself.
• The typical large power plant has 20 to 30 year
  financing.

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Choose a NABCEP-certified Solar Energy Contractor
www.nabcep.org
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Enough Solar Energy falls on New York in ONE DAY
to power the state for ONE YEAR
Access this presentation at www.etmsolar.com/expo