Physical evaluation

The physical evaluation of a site aims to gather all the necessary information about the geographic location, building construction and the landscape surrounding the building. All of this information can be gathered through a visit to the site and conversations with the owner of the property. The goal of the physical evaluation is to obtain as much of the basic information listed below as possible, take photos of the building/surrounding area, and create a simple map of the location. If accessing the site is complicated, an additional map detailing the route to access the site should be created. During an evaluation there are typically additional questions that arise that are specific to the site and other details that are noteworthy, these are valuable notes that should be recorded as well.

Basic evaluation

Example of a simple site drawing.

Owner

• Name of owner:
• Phone number:
• Email:

Geographic location
It is very important to understand how a location can be reached for a potential future installation. Information about the surrounding landscape can provide information about shading and other weather or environmental issues that may arise.

• Address:
• GPS coordinates:
• Altitude:
• Access (time and means of transport):
• Surrounding terrain (mountains, jungle, open plain):
• Common grid-supplied AC voltage and frequency in this area:

Structure
The usage of the structure, size and type of construction will inform decisions about wiring, physical wire protection, and system size. Type of structure (home, workshop, office, clinic, school):

• Frequency of use/occupancy:
• Dimensions of the structure (drawing):
• Type of construction (brick, concrete, wood, adobe):

Current electrical system
If the building currently has electrical system, of any kind, it should be evaluated to make sure that it has been properly installed and is functional. There is additional information that should be gathered as it may be useful in the design later on.

• Location of distribution panel:
• Type of distribution panel (brand/model):
• Document the overcurrent protection devices and circuits in panel (photos):

User needs and expectations
It is very important to understand the intended use of the system and the consequences of a power outage. A system that serves a critical function – like at a clinic – must have a more robust design with more PV and a larger battery bank to reduce the potential of a weather-related outage. A generator may also need to be incorporated.

• Can the user adjust load use/power consumption according to the weather:
• Consequences if the system is not operational due insufficient capacity:

Location of PV source
It is important to evaluate the potential mounting system types, location for the PV and any shading issues that may occur throughout the year together. A hand-drawn map documenting any potential shading issues and proposed locations for the PV source is the minimum that should be done. A proper shade analysis with a tool like the Solar Pathfinder is recommended for any location that may have serious shading issues. If a system is to be mounted on the roof of a structure then the angle of that roof surface, the direction that it faces relative to North/South, its condition and the underlying structure should be documented.

• Potential shading issues:
• Recommendation for mounting system and location:
• Alternative recommendation for mounting system and location:

Location for electrical equipment
It is ideal that the other system components – charge controller, inverter, energy storage and power distribution – are all located in a central location that is dry, clean, easy accessible, and meets requirements for Equipment clearances and safe working space Recommendation for electrical equipment location:

• Alternative recommendation for electrical equipment location:

Site drawing
A site drawing is the most effective way to convey many details about a site and potential equipment locations. A drawing should include the following useful information:

• Dimensions for all structures
• Distances between all structures
• All potential locations for system components.
• An arrow that identifies the orientation of the map relative to the compass.
• All potential shading hazards with an estimation of their distance from the structure and height.

Photos

• Structure (interior and exterior)
• Roof (underlying structure and surface)
• Surrounding landscape
• Current electrical system
• Any loads present at the location including information about power consumption
• Additional notes
• It is important to note any other information that may be valuable.