A virtual bus trip to photovoltaic sites in
the Connecticut River Valley and beyond
Morton M. Sternheim, mort@umassk12.net
Rob Snyder, snyder@umassk12.net
NSTA April 13, 2013
DIVERSIFIED CONSTRUCTION SERVICES, LLC
100 University Drive
Amherst, MA 01002
PROGRAM CONTRACT ED-IES-11C-0022
www.umassk12.net/solarlab
www.umassk12.net/stem/materials.html
Photovoltaic solar cells
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Photovoltaic solar cells convert light from the
sun into electrical energy
“Solar Panels” or “solar arrays” of these cells
have many uses
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On the road
In campgrounds and parks
In homes
In schools and businesses
Can you think of other places they can be used?
The bus tour can start at
home
 Many calculators have
photovoltaic cells that
transform light into
electrical energy.
 The light source can be
the sun or indoor
lighting.
 You never have to buy
batteries for these
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These are pretty
common
 Photovoltaic driveway markers and lamps
store energy during the day for night time
use.
Amazon.com
Other off the grid
rechargers
For cell phones, laptops and flashlights
Amazon.com
On the road
 Photovoltaic arrays provide electricity for many
road signs.
 Photovoltaic cells can charge batteries for night
time use.
A school zone blinker light on
East Pleasant Street in Amherst,
MA
On the road
 Photovoltaic road signs can be portable.
This is a construction warning sign at UMass Amherst.
Further from home ..
This is a parking permit machine in Florida
Even further …
 Photovoltaic panels are great at locations
far from the electrical grid system.
Solar power runs
fans and lights in
a Utah rest room.
Lighting
 Solar street lights
and parking lot lights
can reduce our
carbon footprint.
The Mullins Center at UMass Amherst
Photovoltaic arrays on
homes
Amherst
Excess
electrical energy
can be sold to
the utility
company
Northampton
This is a dual use
photovoltaic array
This array at a
cohousing parking lot
in Northampton, MA
provides shade as
well as electricity.
Communities are installing
photovoltaic arrays at schools
Shutesbury
Elementary School
A 95 kW array at Smith
Vocational and Agricultural HS,
Northampton, MA
On libraries
Wendell Free
Library, Wendell,
MA
Milne Library,
Williamstown, MA
Agricultural use of
photovoltaic arrays
 Farmers can grow crops
or graze cattle under
arrays mounted on poles
100 kW array at the
Edwards farm on route 47 in
Hadley, MA
UMass farm on River Road in
South Deerfield, MA
The Western Mass Electric
Company is installing
photovoltaic arrays
8200 panels produce 2.3
megawatts in Indian
Orchard, Springfield,
enough for 500 homes
This 1.8 megawatt
site at Silver Lake in
Pittsfield has
operated since
October, 2010
The Northfield Mountain
Recreation Area Array
First Light has
installed 18,000
panels on 11
acres that can
produce up to 2
megawatts of
electric power.
http://www.firstlightpower.com/northfield/
Much further from home!
 You can’t really see
them, but solar
panels are a source
of electrical energy
for artificial satellites.
The U. S. Department of Education is
providing funds to install photovoltaic arrays
at schools in Western Massachusetts
DIVERSIFIED CONSTRUCTION
SERVICES, LLC
100 University Drive
Amherst, MA 01002
www.umassk12.net/solarlab
PROGRAM CONTRACT ED-IES-11-C-0022
STEM Solar Labs are
installed on 13 school
campuses
Hopkins Academy,
Russell Street,
Hadley MA
Northfield Mount
Hermon, Northfield, MA
The STEM Solar Lab
project
 Assesses site suitability, soil conditions, obtain
building permits
 Installs support structures & panels
 Provides curriculum materials that can be
integrated into existing courses
• PowerPoint presentations, student write-ups, teacher
guides are online at: www.umassk12.net/solarlab
• Teacher training and materials are provided
• The Enphase monitoring system provides electricity
production data
The SSL installation
process
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A site with southern exposure is
selected.
The soil is tested to a depth of 10
feet.
Heavy machinery drives long
posts deep into the ground to get
below the frost line.
Fins provide stability.
Features of SSL curriculum
materials
 Students can
• Do plant growth experiments.
• Measure efficiency.
• Study weather effects.
• Learn how to determine which way is true
south.
• Locate suitable sites for a SSL.
• Construct models of STEM Solar Labs.
• Monitor electricity production of an SSL.
Photovoltaic solar kits can be
used for classroom activities.
Photovoltaic cells like those in the kit in the
photograph transform light into the electrical
energy that can then be transformed into other
forms of energy.
Students learn how to use
meters to study:
 The effect of connecting
photovoltaic cells in series and in
parallel
 The efficiency of a photovoltaic
array.
 Maximum power output
 Module/array sizing
 The rate of energy transformation.
 The effect of the tilt and direction of
a photovoltaic module on electricity
production.
The STEM Solar
Lab output
 The SSL modules have a peak output of about 230
watts. Inverters convert the DC to AC.
 The SSL array has 8 modules, and a peak output
of 1840 watts = 1.84 kW
 The average US home uses about 1 kW
 Typical summer output is equivalent to peak power
for about six hours per day
 (1.84 kW)(6 h) ≈ 11 kWh
 A cable connects the array to the school and
provides energy to replace part of the electric
company supply.
The Enphase web sites provide electrical power
and energy production data.
The Enphase web site provides graphs of
electric power production.
The Enphase web site also provides
environmental benefits information.
The carbon offset is an estimate of the number of mature
trees that can absorb the CO2 that would have been
produced if fossil fuels had been used to produce the
same amount of electrical energy.
STEM Solar Lab web site:
www.umassk12.net/solarlab/