Team Solar PDR
Solar Energy Predictor
Capstone Spring 2009
Daniel Seltzer
Jim Love
Rob Chadil
Eric Dickey
Brief Overview
A portable device used to accurately estimate the
amount of solar energy that can be harvested at an
arbitrary location.
The device should take into account solar panel tilt,
elevation, and geographic location.
System output will show the power a solar panel
could theoretically harvest over the course of a year
at the chosen location.
Purpose
The need for this device comes from rapid growth in
the commercial and home solar Photo-Voltaic (PV)
industry.
At present, the margin between making or loosing
money with a PV installation is quite small.
More accurate information means better decisions.
Theory – Hemispherical Photo
Theory – Sky Detection
(Estimated White Sky/Black Object )
N
W
E
S
Theory – Sun Path (1/29/2009)
N
W
E
S
Sun Path Results
(January 29, 2009 – Clear All Day – 4.89 kW·h / M2 )
The User Perspective
Compass
GPS
Data Capture Device
Tilt
Personal Computer
System Organization
Circular Fisheye
Lens
Camera
(IP)
SD Card/USB
ThumbDrive
Single Board
Computer
Software Modules
Data Capture Device
Image Processing –
Sky/Obstruction Alg.
Pic Buff
(SRAM)
Compass
Tilt
Sensor
Microcontroller
Number
Pad
GPS
Character
Display
Camera Orientation
Compensation
Sun Tracks Algorithm
Final Power
Calculation
User Interface
Sensor Module
Windows Laptop
Battery Power System
Single Board Computer
• Small (3.8’x4.8’) Single
Board Computer.
• ARM9 Based
• Light weight Embedded
Linux OS preloaded, with
support for Debian if
needed.
• Used to coordinate
between Sensor Module,
Camera, and removable
media for data storage.
Sensor Module Board
Image Capture Module
32 Bit
Parallel
User Interface
LCD Screen
8 Bit
Parallel
SRAM
1 MB
Microcontroller
32 Bit ARM7
50 MHz
Keypad
I2C
Compass
Module
UART
GPS Receiver
3
Channel
Analog
Tilt Sensor
Image Capture
• Small camera fitted
with fish eye lens.
• Communication over
Ethernet simplifies
interface.
• Gives 180° view of
horizon.
User Interface
Solar Energy Predictor v1.0
File Edit Import Help
Show…
Sky boundaries
Sun path
Diffuse light approximation
Gamma pre-distortion
Textual Output Area.
Numbers such as total yearly expected,
total daily expected. Used to compliment
graphs.
Some other thing to select
Sky Threshold
1/24/2009[8:52:01]
1/24/2009[8:53:12]
1/24/2009[8:53:56]
1/24/2009[8:54:03]
Solar Predictor Console
Users See Status messages here
Not an interactive prompt
Basically just a status message box.
Day Select
6/23/2009
Year Select
2012
System Verification
Need a way to tell if system is giving reasonable results.
Hand-Calibrate
Estimate for one day, then borrow a solar luminosity meter
and take the full day measurements by hand.
Calibrate using Charts
Estimate for a year, at a location with few horizon
obstacles, then compare to similar charts from NOAA,
NASA, etc.
CDR
2/24
Milestone 1
Milestone 2
Expo
3/17
4/14
4/30
Sensor Module PCB
Rev 1 Schematic,
Layout, and Ordered
Sensor Module
powered and with
component interface
code written
Sensor module
software complete
Linux Functional on
SBC. Image
Capture/Processing
on Debian Machine
functional.
Image capture from
single board
computer
Sensor module fully
integrated with single
board computer
Algorithms completed
in MATLAB
Basic user interface
on windows
computer, algorithms
converted to C#
User interface
completed
Full system test
completed
Budget
Fisheye lens
IP Camera
Single Board Computer
PCB's (2 with stencils)
Compass
GPS
Misc/Other IC's
LCD
Keypad
Total
$114.99
$250.00
$337.00
$250.00
$143.95
$59.95
$35.00
$17.99
$25.00
$1,233.88
Risks and Solutions
Cant get camera to talk to
Embed Linux computer.
Tilt/Compass/GPS not
sensitive enough to give
results that we need
PCB layout mistakes or
board population mistakes
• Have started work early, and results look good
• Modular testing, starting with windows, then Linux, then SBC
• Have chosen an IP camera for OS compatibility
• If sensors are not accurate enough, could throw results off enough to
make whole device useless
• Can use redundant measurements and average results, either by
sampling single device multiple times, or by using multiple devices.
• Scheduling time and budget for a second board revision
• Full Team review before ordering boards.
Going Further
•
•
•
•
•
Graphical image preview on unit.
Built in rechargeable battery power pack.
Remote camera trigger
Account for single/dual axis sun tracking
Always more variables to account for. work
these into GUI to give better estimates
Questions?
Project Schedule