Cover Your A$$ets Solar Panel Protection Project Team: Krista Miller Sohaib Hasan John Helme.

Cover Your A$$etsSolar Panel Protection

Project Team:Krista MillerSohaib HasanJohn Helme

What is the problem? Passive solar panels

collect energy in the form of heat. It is possible for the temperature of these panels to exceed a desirable limit.

One solution is to “dump” hot

water and add cold water.

Normal Solutions

Another solution is to use a “large” thermal like a swimming pool or the earth.

These options are not always viable.

Problem Statement The maximum temperature that a passive solar

panel can reach must be controlled. The temperature control system must work without using additional water. When not active, the control system shall not interfere in the efficiency of the solar panels.

Solution Constraints:The solution must: Work on any number of panels. Have both an automatic and manual control. Have user adjustable temperature setting. Have a maximum cost of $200 per panel.

Summary of SolutionsSolution Resolves

ProblemEconomically Feasible

Conserves Energy

Uses Electro-mechanical systems

Dump heat into ground

Yes No No No

Sterling Engine

No – limited heat dissipation

Unknown Yes Yes

Seebeck Device

No – limited heat dissipation

No Yes Yes

Energy Blocking

Yes Yes No Yes

Solution Statement Blinds will be automatically positioned to

cover a solar panel before the panel temperature reaches a critical level.

Each solar panel will:

Have a complete and independent blind system.

Have adjustable temperature controls.Be controlled by a single override control.

Microcontroller

Position Sensors 1-3

Temp Sensor

M

Increment

Motors

Manual Override

Power

Motor Controller

System Diagram

Above is a picture of how the solar panel cover will be mounted on the existing panels.

Mechanical System Diagrams

Cover

Heavy Duty Premium White Tarp

6 oz per Square Yard 1200 Denier UV Treated For Longer Protection 12 Mil Thickness 14x14 Weave Count Water-resistant Rot-proof Dust-proof.

DC Motors & Motor Driver:

Motor Denso 730557-7030 12V, 3.3A 163 RPM 100 oz in torque

Motor Driver H Bridge

Temperature Sensing Diagram Type K Thermocouple

Self Powered Simple Rugged Inexpensive Wide Temperature Range

Thermocouple Processing/Conditioning

Electronics Overview

Open Limit Switch (in back)Covered Limit Switch

Mid Position Limit Switch

Microcontroller Freescale HCS08

10bit A2D converter Ease of use Inexpensive Available Code

Position Switches SPST Momentary Roller Switch

State Diagram

Start0 0

Open00 1

Idle10 0

Idle 00 0

Idle½0 0

Open½0 1

Close1 0

Start0 0

Close½1 0

Motor close Motor openp.open<>1

elsep.open=1

else

elseelse

pos.hw=1

else

or.open=1 or

temp<s.open.ref

or.clsd

=1

pos.

clsd

=1

temp>s.clos.ref ortemp>c.clos.ref or

or.clsd=1

pos.hw = 0

temp<s.open.ref

or.o

pen=

1

Reference Variables

Standard close temperature s.close.refCritical close temperature c.close.refStandard open temperature s.open.ref

These values will be set usingpotentiometers on the controller circuit.

Sensors

Sensor VariablePanel open pos.openPanel 1/2 open pos.hwPanel closed pos.clsdTemperature temp

Override ControlsControl VariableOpen or.openClose or.clsd

temp>s.close.ref

Budget for Major and Minor Components Demonstration

UnitProduction

UnitMechanical System $75.00 $120.00includes- gears, belts, chains, bearings, bearing blocks and mounting hardware

Electronic System 35.00 35.00includes- microprocessor, sensors, switches, circuit boards and other support circuitry

Motor Donated 25.00

Enclosures 20.00 25.00includes enclosures for motor, electronics, over ride controls

Power Supply N/A 50.00

Cable and connectors $10.00 $10.00

Cover Material $10.00 $30.00

PVC Demonstration frame $35.00 N/A

Total $185.00 $295.00

Informative Schedule, Balanced Personnel Assignments, Milestones

TasksCompletion Date Assigned To

Milestone Completed

I: Problem Definition and Solution Identification 12/5/2006

II: Research 1/20/2007

III: Physical Modeling and Feasibility Tests 2/6/2007

Mechanism Concepts – interference, linkages 1/16/2007 Krista

Circuit simulation 1/23/2007 Sohaib

Sensors – output and amplification 1/31/2007 Sohaib

Component coupling 1/31/2007 Krista and John

Power and torque perfomance – manual torque tests 1/31/2007 John

Heat transfer, temperature control 2/29/2007 Krista

IV: Design 2/13/2007

Material selection, justification 1/31/2007 John

Mechanical drawings – brackets 2/6/2007 Krista

Electrical Diagrams – circuit boards, power distribution 2/6/2007 Sohaib

State diagrams and flow charts 2/6/2007 John

System diagram with components and interface signal details 2/20/2007 All

V: Build 3/6/2007 All

VI: Subsystem Test 3/14/2007 All

VII: System Integration 4/3/2007 All

VIII: Functionality test and Demonstration All

Summary Problem: The temperature of the

solar panels must not exceed a maximum temperature.

Solution Constraints: Must work on any

number of panels. Must have both an

automatic and manual control.

Must have a maximum cost of $200 per panel.

Solution: Solar panels will be

automatically covered when they reach a set temperature.

Solution Constraints: Controller and motor for

each panel. Open, close and power

off override controls. Demonstration system

estimated cost of $185.