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Course Title
100 Home
101 Introduction
102 FAQ Page
103 Course Catalog
104 Green World
105 Demand & Supply
106 Conservation Careers
107 Solar Careers
108 Wind Turbine Careers
109 Entrepreneurs
110 Employee or Employer?
200 Demand Management
201 Summary
202 Residential Energy Profile
203 Ten Conservation Rules
204 HVAC System
205 Kitchen Appliances
206 Water Heater
207 Lighting
208 Laundry Appliances
209 Calculating Savings
300 Renewable Technology
301 Solar Energy
302 Solar Collectors
303 Solar Water Heating
304 Stirling Engines
305 Basic AC-DC Electronics
306 Silicon Solar Panels
307 Thin Film Solar Panels
308 Wind Turbines
309 Inverters
310 Grid Tied and Off Grid
311 Solar Site Survey
312 Solar Site Diagram
313 Sun Path Chart
314 Site Survey Worksheet
315 Wind Turbine Site Survey
316 Wind Turbine Worksheet
400 Solar Thermal Design
401 Solar Heat Overview
402 System Configuration
403 Site Survey
404 SRCC Compliance
405 System Specification
406 Bill of Materials
407 System Installation
408 Solar Heat Incentives
409 Document Package
410 Future Products
500 Solar PV Design
501 Solar PV Overview
502 System Configuration
503 Site Survey
504 Grid Tied & Off Grid
505 System Specification
506 Bill of Materials
507 System Installation
508 Solar PV Incentives
509 Document Package
510 Future Products
600 Wind Turbine Design
601 Wind Turbine Overview
602 System Configuration
603 Site Survey
604 Grid Tied and Off Grid
605 System Specification
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Green Collar Careers - Solar Electric Site Survey

The same Solar Site Survey process used for solar heating will also be used for the solar electric PV system with a few simple additions for the PV equipment.  If you looked the Site Survey Data worksheet over carefully you may have wondered when we would get to the solar electric portion.

With the best wholesale cost per kWh based on turkey kits the key will be to determine what size kit works best.  At the time of this page edit, complete Grid Tie quality kits were selling for under $4 per DC Watt.

The Site Survey Data worksheet will need to be completed down to the Solar PV Requirements section.

We've taken the data from the example file for review below:

Solar PV Requirements
Total Annual kWh Requirement 45000
DC Watt Output Rating of Kit 8000
Quantity of Panels in Kit 40
Rated DC Watts Per Panel 205
Panel Width Inches 35
Panel Height Inches 65
Customer Price $36,200
Installed cost per DC Watt $4.53
Utility Incentive per DC Watt $2.46
State Tax Incentive Estimate $0
Utility Incentive Total $19,680
Federal Tax Credit $10,860
Projected Annual kWh Output 11200
Percentage of Solar Electricity 25%
Projected Annual Electricity Savings $1,456
Square Footage of Panels 632
Net System Cost to Owner $5,660
Return On Investment Years 3.9

This example comes from a real job that was installed in June 2009.  It consisted of an 8000DC Watt ground mounted panel system and was installed in Texas.  The local utility was Oncor who is currently paying out $2.46 per DC Watt to collect on the Carbon Credits the system is capable of generating.  Texas has no state taxes and therefore no tax credits.

The number of sunny days directly determines the annual output.  This 8000 Watt system is projected to provide 11,200 kWh of electricity per year, and amounts to 25% of the total used by this household.  This homeowner uses a bit more power then the average in part due to a small business operated out of the home that has a few high power appliances in operation 8 hours a day.

On this particular home the roof angles just wouldn't result with an attractive and easy to service system.  You'll probably find that in 2/3's of all the site surveys you perform.  Solar PV panels lend themselves to a creative eye.  If the roof doesn't meet the best fit consider awnings or even a stand-alone ground mount.  In this installation the panels were mounted adjacent to a pool that provided a 55 foot long 12 foot tall privacy fence and is an attractive feature of the landscape.

Once you've identified the equipment locations measure out all cable lengths.  A list of interconnections is listed the Solar Site Survey on the Solar PV Interconnect Worksheet.  The key distances you'll need to measure are:


Originating Terminating Length
PV Panel Combiner Box  
Combiner Box DC Disconnect  
DC Disconnect Inverter  
Inverter AC Disconnect  
AC Disconnect Main AC Panel  


Be sure when you measure cable route lengths that every X, Y, and Z axis length is included in the total length!