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Green Collar Careers - Site Survey

Every customer will have a different installation need no matter the similarity between buildings.  The best place to begin is looking up the potential customer's building on Google Maps.  Try it on your own home, and zoom in full view; not all homes in America will zoom in full view, most will.  Look for the best southern exposure.

The Site Survey will require a documented plan that includes the following documents you'll prepare:

1. Site Survey Worksheet
2. Site Diagram

These documents will be part of the documentation package completed by the System Installation phase.

1 Site Survey Worksheet

The Solar Site Survey Tool captures the data relevant to the site and calculates basic performance specifications.  Both demand data and supply data is entered with several data points defined through the use of proven formulas and macros.  Only the white colored cells are to be filled in.  All Gray color cells will use a formula or macro to fill them in.  Most of the data should be filled in prior to a site survey is done however some of the customer data such as utility information may not be available until the site visit.  The important part is to have the latitude, longitude and related data to generate the preliminary Site Diagram.

Worksheets:

Site Survey Data

• Customer Data
• Utility Data
• Home Data
• Available Thermal Energy
• Water Heat System Requirements
• Solar PV Requirements
• Wind Turbine Requirements

Regional Solar Data

• Latitude and Longitude for most major cities in America - needed for Site Survey Data
• Annual Sunny Days - needed for Site Survey Data

Solar Position

• Will be used to calculate solar azimuth and elevation for summer, fall, winter, spring milestone dates.  Latitude and Longitude will first need to be entered on the Site Survey worksheet.
• Input the time values in (Year, Month, Day, Time, GMT, 0 for DST) in for each season, hit enter and manually record the azimuth and elevation for each season - this will automatically carry over to other worksheets.

Sunrise

• Calculates the effective length of day
• Input the time values for each season, hit enter, and record data.  Again, the recorded data is carried to other worksheets.

Regional Wind Speed

• This worksheet will be discussed in the Wind Energy module

Solar Site Survey Tool Practice Run

1) Open the Solar Site Survey Tool and save it to a new folder you've created.  You can manage your own filing system, but I would recommend naming the folder "Solar Thermal Surveys" and giving the file a name of
"YYYYMMDD-YourName-1".xls.  This will position the file by chronological order with the customer's name for future reference.  The "-1" is in case you want to revise the form yet keep the original.

Note: Fill in ONLY THE WHITE CELLS! All gray cells are filled in by formulas or macros

2) Select the Site Survey Data tab and complete the Customer Data in rows 2-13.

3) Complete the Utility Data in rows 15, 16, 17, & 19.

4) Complete the Home Data in rows 23-25.

5) From the Google Map determine which section of your roof has the southernmost exposure.  Go out and take a look at it and estimate the number of feet in the X direction, and the number of feet in the Y direction, and add that to the sketch.  Take a compass and measure the angle to the nearest degree of the wall that lines up with the roofline, and show that on the sketch.  Note where due north/south is by the compass in relation to the roof surface.  At this point you won't need to be exact but a good scale sketch is a good sign of true professional interest!

6) Measure the pitch of the roof as best you can;  Access it from the attic take protractor and measure the angle of the roof slope.   If you don't have a protractor use a level and tape, measure the the horizontal distance and the vertical distance, then using Pythagorean's theorem calculate the angle.  While you're in the attic look for the routes you'll be running the fluid transfer lines between the collectors and storage tank. 

7) Walk around your lot and site off the path of the sun through the day - are there any sun obstructions like trees or other objects that will create shadows on the roof surface?  Remember that the sun will be higher in the summer months and lower in the wither months.  Label these obstructions on the sketch.

• If there are no obstructions and the roof surface is aligned within 25° of south facing, it will be a suitable surface to mount collectors.  Collectors do not need to be mounted flush on the roof, in fact despite what you may see in pictures that is actually bad practice.  Collectors/Panels should always be elevated slightly above the roof tiles to give some access to roof tiles.
• If there are obstructions the choices are simple;  either remove the obstruction, change the mounting location, or de-rate the system to operate only within the window of available sunlight. 

7) Fill in 26, 27, 28 of the Home Data with measurements and notes you've taken.  By this time you should have a pretty good idea of where the system will mount.

8) If you don't know the longitude and latitude of the subject home Google Maps will have it, or it can be found on the Regional Solar Data tab.  You don't need it down to the minutes and seconds.  Under the Available Thermal Energy section fill in rows 35 and 37.  The data in these two rows will automatically populate a few other cells we'll visit later.

9) Select the Regional Solar Data tab and look up the city (or closest city) where you're doing the survey.  Look up the "Sunny Days a Year" value on the Site Survey Data worksheet row 38.

10) Select the solar_position tab and look at the Input Column a moment.  Latitude and Longitude values came from the inputs at step #8.  Over on the right side under columns 3, 4, 5, &6 you'll see a box with a heading "Use these Settings".  Under Summer '6' is listed for the month, '21' is listed for the day and so on.  Key those numbers in for the corresponding cell and hit enter, which updates the azimuth and elevation values.  For each season record those values in the boxes under where it says "Record the Values".  Those values will populate the Site Survey Sheet.

Tip: Output values on the solar_position and sunrise worksheets may not be "cut & paste" in the normal way as they are the result of a macro.  You can right click for "Paste Special ", click the Value radio button, and paste the value.

11) Select the sunrise tab and once again run through the exercise to record the data for each of the seasons.

12) Select the Site Survey Data tab and notice that the remaining Available Thermal Energy cells have been filled in.  Doing all that manually the first time would have probably taken several days if you already had the formulas.  Weeks if you had to find the formulas.  Minutes using the worksheets provided.

For the most part that is the site survey.  We may appear to have gotten a little bit ahead of ourselves as we reviewed the Water Heat System Requirements in the previous chapter.  As you recall we actually reviewed a completed sample.  Now lets complete this survey.

Check the water heater temperature and input that value to Temperature on row 57.

From what you learned in 401 Performance Specs identify and input the value for Solar Collector Efficiency %.

Finally input the Solar Water Heating Percentage, and save the file.

2. Site Diagram

From the preliminary Site Survey Data, open the following Sun Path Chart tool provided by the University of Oregon to plot out an image of the chart to visually represent the Solar Altitude and Solar Elevation for the site.  This will help to orient the sketch.

Using Google Maps draw a sketch of the lot with the building and roof lines.  Try to remain within scale the best you can using a ruler to keep lines straight. 8-1/2 x 11 paper is OK if you're neat, and graph paper actually works pretty well for some people.  Keep the north/south position aligned with edges so you can overlay the Sun Path Chart.

Note the trees and other obstacles that may possibly obscure the roof and mark that up on the sketch.  This will be your preliminary sketch not necessarily the final draft you'll put together after the survey has been done.

In the event the roof line is off by more then 20° alignment to south, look for potential ground mounting of the collectors. 

Most counties have a tax information site you can locate in the Search Tool below.  Property tax records will tell you the name of the owner, when the building was built and how many square feet it has. 

Sales Tip - Homes that are less then 12 years old are likely to have the original water heaters and if so they are generally the cheapest "builder's specials" on the market.  Builder's specials have shorter lives and are less efficient then what consumers typically replace them with.   The homeowner may be ready for a new water heater that typically would cost $1000 to replace.

Site Survey

You will need the following tools for the Site Survey:

• Compass - with flat edge to line up with a wall, and with degree readouts - a good hiking compass will do
• Protractor - Bubble level preferred although one that can lay on a level is OK.  It will need an angle bar so you can use it to get a line of site on roof angles from the ground
• 100 foot tape measure
• 25 foot tape measure
• Something that can measure a pipe diameter
• Clip Board
• Sharp pencils with erasers
• 3 copies of Sketch - you'll know why after doing your first site survey
• Print out of Sun Path Chart
• Print out of Site Survey Data
• Note pad - graph paper preferred
• Ruler - you'll be doing more sketching
• Digital Camera

1. Verify visual accuracy of preliminary sketch and clean up anything that's not really clear.
2. Take wall measurements to the closest 6" and add the dimensions of the walls to the sketch
3. Note property lines and distances from the house to the property.  There may be obstacles that don't belong to the homeowner or in the event of a ground installation of the solar collector it needs to be on their property and within any boundaries established by local codes.  If you see these types of concerns, document them, otherwise its not that important.
4. Check wall and roof line alignment to the compass and note the readings to within a few degrees - keep in mind the region of interest is southern facing.
5. Using the protractor on level (per bubble) site the roof angles of interest and note that on the sketch.
6. Measure the length and width of the roof section from the ground and try to remain within 6" and add those dimensions to the sketch.  You may need to use the second copy for this.  Identify a corner of the house as a reference point for these dimensions as you'll be using that reference for other things to determine pipe lengths & routes and wiring lengths & routes.
7. Locate the existing water heater and measure the relative location to the reference point you identified in step 6.  Note the floor the water heater is on.
8. Investigate the best path to route the Closed Loop piping from the Solar Collector to the existing Hot Water Heater.  Do not offer to relocate the Storage Tank/Heater, it will only create headaches. 
9. Sketch the room where the hot water heater is located to indicate clearances from walls, access doors, and any objects.  Take plenty of pictures of this room/closet to make sure you have it documented.
10. Inspect the attic area under the proposed solar collector position and determine the most viable routing of the Closed Loop piping.  Keep in mind that the piping must be insulated so blind access or wall drops of pipes is not a preferred solution.  In some cases a wall drop may be the only solution and in that event consider the potential of cutting out a section of wallboard to install the insulation - that will probably add $200 or more to the cost.
11. Take plenty of pictures inside the attic underneath the proposed proposed solar collector position and note the size of the rafters.  Most solar collectors are under 10 lbs per square foot load and usually pose no issues, but be sure in case you're asked for permitting purposes.
12. Draw a sketch of the plumbing path.  Take pictures of everywhere you expect to run piping.  While its not preferred for aesthetic reasons in some homes there is no alternative but to run piping externally.  Always keep that in mind as an alternative route and you will want pictures of all possible routes.  Measure out the plumbing routes, both vertical and horizontal.
13. Identify the water piping used.  In most cases it will be 3/4" copper but don't guess - know what is currently connected to the existing water heater.
14. Note the brand, model, age, size, and capacity of the existing hot water heater.
15. Consider any alternative ground locations for the solar collector.  It may surprise you how many times a ground mount is the best solution, particularly if the hot water system is just on the other side of the wall.  There are even some systems that have been built over a doorway or elevated along a wall as an awning!
16. If this is a roof mount, note the type of roof construction - shingles, metal, tile etc.
17. Interview the homeowner to complete the Site Survey Data and review the proposed location.  Unless you're really confident, you don't have to give them an immediate price on the system, but be sure to give them an estimate within 48 hours.

After the Site Survey

As your preliminary sketch will have lots of scribbles (unless you're extraordinarily neat) you'll probably want to create a clean set of sketches.

1. Solar Path Diagram - top view of building with position of Solar Collector as the bottom center of page.  This should overlay with the Sun Path Chart you created.
2. Mounting Diagram - shows where the solar collector will be located relative to a reference point.
3. Storage/Hot Water tank with relative dimensions to the walls, doors and reference point - include some printed key pictures.
4. Closed Loop Routing Diagram - include any lengths and elbows etc. required.
5. Closed Loop Pump - Location, type (Solar or AC)

Wrapping up the Site Survey and Diagram Documentation

In Section 400 there were 5 documents that you'll need to prepare:

1. Site Diagram
2. Site Survey Worksheet
3. System Diagram - plumbing & electrical
4. Bill of Materials
5. SRCC Compliant Permit

After you've completed the Site Diagram its best to scan a copy and save it to the same folder your using for the project.

The content on this page is pretty in-depth for a new comer, don't worry.  After reading through some of the following sections you'll probably want to revisit this section and it will all make sense by then.