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Green Collar Careers - Solar Site Survey Worksheet

 

The Solar Site Survey Worksheet 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.

Solar Site Survey Tool Tutorial

This tutorial will focus on Solar Hot Water systems.  Solar electric systems inputs will be identified in the 500 Module.

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.

Input the value for Solar Collector Efficiency % - for the purposes of this tutorial we'll use 35%.

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