Solar Power Engineering offers a wide range of engineering services from the initial site evaluation all the way through verifying that your system is performing as efficiently as possible.
Many conceptual designs can be completed using aerial imagery, thereby not requiring a site visit. This is the recommended method for the initial site evaluation in order to provide a go/no go status. Once this initial evaluation is done a site visit can be completed to take more detailed measurements, identify obstacles that would cause array shading and determine the location and method of interconnection.
Systems can be modeled in various software programs to allow for an estimate of the system production and losses. By modeling and estimating the system production, decisions can be made relative to system size, orientation, tilt, technology, etc. This type of evaluation is critical in selecting the most cost effective system type and components to be used. Various tools used are PVWatts V2, Solar Advisor Model and PVsyst.
One of the first steps in determining the viability of a PV system is to understand the method of interconnection and any utility upgrades that are necessary to allow for the interconnection. Most utilities require that a formal interconnect application be filed prior to any research or evaluation being completed to determine the impact of the PV system on the existing utility distribution system. SPE can prepare the interconnect application along with the required stamped electrical site plan and system one-line diagram. SPE can then work with the utility thru the interconnection process, ensuring that the PV System owner gets the most cost effective interconnect solution.
Depending on the size of the PV system, there may be complex permitting requirements. SPE can provide the necessary testimonies and exhibits that may be required for permitting.
There may be times when a more detailed design, beyond a conceptual design, is required. This may be to allow for more accurate construction cost estimates or to iron out some of the unknown design issues that may exist. SPE can provide schematic design drawings, which may include: Electrical Site Plan; Array Layouts; One-Line Diagram with conduit and wire sizing; Block Diagram for the metering and monitoring system.
In order to ensure that the PV system owner gets the highest quality and therefore the most efficient and reliable PV system, it is critical that a complete and detailed set of construction documents be prepared. SPE will produce a full set of construction documents, which would include but not be limited to the following:
Project Title Sheet: Includes Electrical Legend, Drawing List and Construction Notes and Specifications
Electrical Site Plan: Overall plan showing entire array and then blow up views of different sections of the array showing combiner locations, conduit routing, conduit sizes, etc.
One-Line Diagram: One-Line with Bill of Materials and all wiring tagged and identified
Schematic Diagrams: Schematics for typical string wiring, monitoring system, grounding, etc.
Stringing Plans: String wiring for each string combiner box
Electrical Tables: Tables that show the calculations for conduit and wire sizing. This will include voltage drop calculations.
Construction Details: Details specific to equipment installations. This includes layout and elevations for the inverter pad, typical mounting for the combiner boxes, etc.
Labels and Markings: Safety and identification labeling for all system components
SPE can prepare testing and commissioning protocols and reports specific to the project. SPE will then conduct and/or oversee the testing and commissioning activities and ensure that the system meets all of the necessary requirements to be a fully functional operate as efficiently as possible. These commissioning activities may include: Inspection of both AC and DC system; Conductor meggar testing; String Open-Circuit Voltage testing; String Operating Current testing; Total System Production (Actual versus Predicted).
Review and evaluate data from the monitoring system to determine if the PV system is performing as expected given the environmental conditions, specifically the irradiance and module operating temperature.