Site Surveys and Preplanning Preliminary Assessment Site Surveys

Site Surveys and Preplanning Preliminary Assessment • Site Surveys • Preparing Proposals • Installation Planning

• The installer should meet with each customer to discuss available PV system options.

• Information gathered during a site survey should be carefully documented.

• A variety of testing and measuring devices and marking equipment is used during site surveys.

• The density of the module arrangement in an array affects the accessibility and the area required to produce a certain amount of power.

• Roof slope is measured with an angle finder or calculated from the rise and run.

• A compass is used to determine the orientation of a sloped roof surface.

• The potential loss in receivable solar radiation from non-optimal orientations may not be significant.

Recall • Why is it in the customer’s best interest to have a dense array arrangement vs an open array arrangement?

• Directional bearings from magnetic compasses must be adjusted for magnetic declination.

• Magnetic declination varies by location and changes slightly over time. Up-to-date maps are used to determine the necessary declination adjustment. Click on map for magnetic declination presentation

• Shading of PV modules and arrays can cause disproportional reductions in power output.

• Most of the daily solar radiation occurs between 9 AM and 3 PM, so avoiding shading during this period is high priority.

• A sun path calculator is used to evaluate shading at potential array locations.

• When the sun is in the northern part of the sky, shading can be caused by obstructions immediately north of an array.

• The Solar Pathfinder™ analyzes shading for potential array locations by comparing the reflections of potential obstructions on the horizon to a sun path diagram of the solar window.

• Marking the solar window obstructions on the removable sun path diagram creates a permanent record of shading for a particular location.

• A newer, electronic tool for shading analysis is the Solmetric Sun. Eye.

Hypothesize • Take two minutes to connect this information on sun path and orientation o what we need to know about your home. • Your home is facing north and a solar company pitches to you that if you add more panels on your roof, you will generate just as much electricity as a southern facing roof. Is this correct?

• Roofs should be inspected for signs of deterioration.

• The thickness of roof decking and covering can be determined by inspecting the edge of the roof under the eaves.

• Noticeable dips on roof surfaces may be a sign of underlying structural defects.

• Inverters and other system components should be located as close together as possible.

• A site layout drawing shows basic building dimensions and locations of major components.

• A load analysis is part of an energy audit, which is used to evaluate a customer’s energy use for standalone system sizing.

• Data monitoring may involve simple display panels or web sites interfaced with sophisticated data acquisition systems.

Reflect • Take two minutes to summarize what you have learned in 4 -6 sentences.