Renewable Energy Electrical Construction & Instrumentation: Solar, Wind & Hybrid Projects
Electrical Scope Across Renewable Technologies
Utility-scale renewable energy projects share a common electrical delivery challenge: converting energy captured from the sun or wind into grid-compatible power at the transmission level and delivering it reliably under variable generation conditions. The electrical construction scope of a solar or wind project is substantial, covering inverter and transformer installation, medium-voltage collection systems, substation construction, and the SCADA and monitoring systems that give operators visibility into plant performance.
Wikota Electrical Services delivers electrical construction and I&C for utility-scale and distributed renewable energy projects across all 48 contiguous states. The integrated EPC platform through Wikota Design & Construction and Wikota Fab Solutions supports projects from early engineering through field execution and commissioning, with in-house electrical engineering available through Mid-America Services.
Solar Photovoltaic Electrical Construction
Inverter and Transformer Installation
Central inverters and string inverters convert DC power from the solar array to AC power for collection system delivery. Central inverter installation scope covers equipment setting, DC input cable termination from the combiner box aggregation system, AC output cable connections to the medium-voltage transformer, control wiring, and communications connections to the plant SCADA system. Inverter transformers step up the inverter output voltage to the collection system voltage, typically 34.5 kV for utility-scale projects. Wikota Electrical installs inverter transformers including primary and secondary cable connections, CT and PT connections for protection and metering, and transformer grounding.
DC Collection System and Combiner Boxes
The DC collection system aggregates the output of individual solar modules into the combiner boxes and then into the inverter input. Electrical scope covers string home run cable installation from the module rows to the combiner boxes, combiner box installation and string fuse termination, and the combiner box output cable connections to the inverter DC input terminals. Trenching coordination for underground DC cables is managed in alignment with the civil construction schedule to ensure conduit is installed before cable pull.
Medium-Voltage AC Collection System
The AC collection system carries inverter transformer output at medium voltage through underground cable or overhead line circuits to the project substation. Collection system electrical scope covers medium-voltage cable installation in conduit, cable splicing at pull points, termination at the inverter transformer secondary and at the substation switchgear, and cable testing including high-potential testing of the completed cable system before energization. Above-grade collection system components including junction boxes and cable protection structures are installed in accordance with the project’s civil and structural design.
Substation and Interconnection
The project substation steps up the collection system voltage to the transmission interconnection voltage and provides switching, protection, and metering for the facility. Substation construction scope covers equipment setting for main power transformers, switchgear, and capacitor banks, bus work installation, grounding grid installation and testing, protective relay panel installation, revenue metering installation, and the control building electrical installation. Interconnection with the transmission system is coordinated with the receiving utility’s interconnection requirements.
Wind Energy Electrical Construction
Wind Turbine Electrical Scope
Wind turbine electrical installation scope covers the work performed from the tower base to the point of connection with the collection system. This includes medium-voltage cable installation in the tower cable management system, grounding connections at the tower base, meteorological and control cable connections at the tower base junction box, and the medium-voltage cable trench connection from the tower base to the collection system. Turbine pad-mount transformer installation and termination is included where the transformer is separate from the turbine assembly.
Wind Farm Collection System
Wind farm collection systems operate at medium voltage and connect groups of turbines through underground cable or overhead line circuits to the project substation. Collection system scope for wind projects follows the same general approach as solar collection systems, with the additional consideration that wind farm collection cables must accommodate the larger spacing between generation points and the more complex cable routing required by the turbine layout. Overhead collection systems require pole setting coordination with the civil contractor and conductor stringing in accordance with the project’s electrical design.
Hybrid and Distributed Renewable Projects
Hybrid renewable energy projects combine two or more generation or storage technologies, typically solar plus storage or wind plus solar, within a single interconnection and SCADA framework. The electrical scope spans the generation electrical systems for each technology plus the storage integration scope, with a common substation and interconnection. Wikota Electrical manages the coordination between technology-specific installation requirements to ensure that the combined system commissions as an integrated plant. Distributed generation and community solar projects operate at lower voltages and smaller scales than utility projects but require the same precision in inverter installation, collection system construction, and interconnection compliance.
SCADA, Monitoring, and Controls
Renewable energy plant SCADA systems provide operators with real-time visibility into plant performance, including active power output, equipment availability, meteorological data, and alarm status. Wikota Electrical installs SCADA field devices including met mast instrumentation, string-level monitoring connections, inverter communications interfaces, and the plant-level SCADA server and operator workstation. Revenue metering at the point of interconnection is installed to the utility’s metering standards. Remote monitoring interfaces allow the plant owner to access performance data from the energy management center.
| Electrical Construction | Inverter and transformer installation, DC combiner box installation, AC collection system construction, substation electrical, interconnection scope, and wind turbine base electrical. |
|---|---|
| Instrumentation & Controls | Plant SCADA field device installation, met mast instrumentation, revenue metering, protection relay installation, and commissioning for solar, wind, and hybrid facilities. |
| Engineering & Design | Power systems design, collection system design, protective relay coordination, arc-flash analysis, and electrical drafting through Mid-America Services. |
| Project Delivery | Full EPC coordination with Wikota Design & Construction, construction management, commissioning, pipeline operator coordination, and project visibility. |
| Safety, Quality & Compliance | Zero recordable incidents, ISNetworld tracking, NFPA 70E, high-voltage cable testing protocols, and QA/QC documentation for utility interconnection requirements. |
Frequently Asked Questions
A utility-scale solar project electrical scope covers the DC side, the AC collection system, and the substation. On the DC side, the scope includes string home run cable installation from module rows to combiner boxes, combiner box installation, and DC cable connections from combiner boxes to the inverters. On the AC side, the scope includes inverter installation and transformer connections, medium-voltage collection system cable installation from inverter transformers to the substation, and substation construction including main power transformer, switchgear, protection, and metering. Plant SCADA field device installation and commissioning completes the scope.
A medium-voltage collection system aggregates the AC output of multiple inverter transformers or wind turbine transformers at a common collection voltage, typically 34.5 kV, and delivers that power to the project substation through underground cable or overhead line circuits. The collection system is divided into feeder circuits, each serving a group of generation points. The substation switchgear provides switching and protection for each feeder circuit, allowing individual feeders to be isolated for maintenance without taking the entire project offline. Medium-voltage cable in the collection system is installed in conduit, terminated at each end, and high-potential tested before energization.
Solar project commissioning begins with pre-energization inspections of the DC and AC systems. DC inspections include string polarity verification, open circuit voltage measurement on each string, and insulation resistance testing on the DC cable system. AC inspections include cable termination verification, transformer oil commissioning where applicable, and protective relay secondary injection testing. Substation energization is coordinated with the utility and follows the approved energization sequence. Plant-level commissioning verifies inverter startup and shutdown sequences, SCADA data point verification, revenue meter accuracy, and the reactive power control system performance. A final walkthrough and punchlist resolution precede commercial operation declaration.
Solar project electrical scope is characterized by a large number of relatively small DC connections at the module level that aggregate through combiner boxes and inverters to the medium-voltage AC collection system. Wind project electrical scope involves fewer but larger generation connection points, with each turbine connecting at medium voltage through a pad-mount or nacelle transformer. Wind turbine tower electrical includes cable management in the tower itself, which is not present in solar projects. Both technologies share a common medium-voltage collection system and substation structure, but the generation-side electrical work is fundamentally different in terms of the number of connections, the voltage levels involved, and the physical installation environment.