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Green Collar Careers - Solar Site Survey

The purpose of a Site Survey is to determine:

• Solar exposure period and obstacles
• Location and mounting of the solar collectors and/or Solar PV panels
• Define system requirements and specifications
• Location of support equipment; thermal storage tanks, inverters etc
• Routing of plumbing and wiring
• Access and hazards for installers
• Ingress/egress to installed equipment

The following items will be needed for the Solar Site Survey:

• Compass - with flat edge to line up with a wall, and with degree readouts - a good hiking compass will do
• Solar Surveying Tool - Fabricating a Solar Site Survey Transit
• 100 foot tape measure
• 25 foot tape measure
• Something that can measure a pipe diameter
• Clip Board
• Sharp pencils with erasers
• Print out of Sun Path Chart
• Print out of Site Survey Data
• Note pad - graph paper preferred
• Digital Camera

You will also need to create these documents for the Solar Site Survey:

1. Solar Site Diagram - Section 312
2. Sun Path Chart - Section 313
3. Site Survey Worksheet - Section 314

Site Survey

Property Review

Note the time of day and the compass orientation of the property.  Walk around the perimeter of the property to identify the property lines and note any obstacles that will potentially shadow the solar facing equipment.  For example trees that are on the home owners property may or may not be acceptable for trimming.

Use the best practical solution to identifying the location of the solar facing equipment.  Most solar facing equipment tends to be roof mounted as it takes up the least space and reduces attic heating.  Roof top mounting is not always the best option depending on the roof geometry and devices to be installed.  If roof top installation doesn't fit the best solution find a different location that offers the best solution for the homeowner.

Sun Path Analysis

1. Once you've identified the ideal and alternative locations for the solar facing equipment, set up the transit locating true north. 
2. Using the Sun Path Chart that was created for your location, you'll identify the angles of obstacles in relation to the time of day by elevation and azimuth.
3. Aim the transit at the azimuth angles for the first hour of sunlight hour shown on the scale and line up with the lowest elevation angle that's unobstructed to the horizon. At that elevation angle, mark the Sun Path Chart with a dot - and repeat this for every hour.  See example 1.
4. After filling in the dots, connect them - See example 2.
5. 80% of the solar energy through the year is provided in the green shaded region.  You could compute this down to an exact number, but using the 80% Sun Path image as a guide you should be able to determine if the shadows are excessive for the first location you've selected.

If excessive shadowing is a problem for the first location selected you have three options:

• Remove the object creating the shadow
• Relocate the solar facing equipment
• Reduce the efficiency of the solar facing device

Support Equipment Placement

After you've determined where the solar facing equipment will be located comes the support equipment.  For the solar heating system this is usually the storage tank, controller and pump, and for the solar electric system this is the inverter.

There will be cabling and plumbing routes to consider.  Rooftop mounting of the solar facing equipment generally requires an attic routing although that may not always be the best path.  That's what you'll need to determine.

If you choose a site that has isn't attached to the structure its almost certain that your routing path will need to be underground.  Most local codes require conduit or some durable cable specification with junction boxes etc. at exit points.  Buried cables/pipes need to take into consideration of any other buried pipes or wiring including automatic sprinkler systems.

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.

1. Layout a preliminary sketch and identify locations of solar facing equipment and support equipment.
2. Using the transit site the roof angles of interest and note them on the sketch.
3. 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.
4. For solar heating systems, locate the existing water heater and measure the relative location to the reference point you identified.  Note the floor the water heater is on.
5. 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. 
6. 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.
7. 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.
8. 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.
9. 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.
10. 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.
11. Note the brand, model, age, size, and capacity of the existing hot water heater.
12. 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!
13. If this is a roof mount, note the type of roof construction - shingles, metal, tile etc.
14. Interview the homeowner to complete the Site Survey Data and review the proposed location. 
15. For solar heating systems, approximate the total length of tubing (both ways) and the number of elbows and joints required.
16. Identify any requirements for buried cable or plumbing.

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. Mounting Diagram - shows where the solar collector will be located relative to a reference point.
2. Storage/Hot Water tank with relative dimensions to the walls, doors and reference point - include some printed key pictures.
3. Closed Loop Routing Diagram - include any lengths and elbows etc. required.
4. Closed Loop Pump - Location, type (Solar or AC)
5. Review the sketches and drawings with the installer at your earliest convenience to get an estimate for the job. 
6. Complete the Bill of Materials, Installer estimate and system cost and contact the customer to discuss the installation quote.