Quick Facts
What SCADA is
SCADA stands for Supervisory Control and Data Acquisition. It is the computer-based system that monitors and controls industrial processes in real-time. For solar plants, SCADA is the brain of the monitoring and control infrastructure, collecting data from sensors and equipment across the plant, displaying it on operator dashboards, and supporting remote control of plant operations.
A modern utility-scale solar plant of 50 MW or larger relies on SCADA for nearly every operational task. Operators in a control room (often remote from the plant) view real-time generation, identify faults, adjust settings, and coordinate maintenance through the SCADA interface.
For rooftop solar above 100 kW, SCADA-like monitoring is also standard, though the system complexity scales down. For smaller residential and commercial rooftop, manufacturer cloud portals (such as Sungrow iSolarCloud, Huawei FusionSolar) provide simpler equivalents.
What SCADA does in a solar plant
A solar plant SCADA system performs four main functions.
Data acquisition: Collecting data from inverters (AC output, DC input, voltage, current, temperature, fault codes), energy meters (plant export, demand, power factor), weather stations (irradiance, ambient temperature, wind, module temperature), string-level monitors (per-string current), switchgear (circuit breaker status), transformers (oil temperature, alarms), and battery systems (state of charge, voltage, current) where storage is integrated.
Visualisation: Displaying the data on operator dashboards. Plant overview screens show key metrics at a glance. Detail screens drill down into individual inverters, strings, or equipment. Historical trends show performance over time. Alarm dashboards highlight active issues.
Supervisory control: Remote operations on plant equipment. Operators can turn inverters on or off, adjust power factor settings, change MPPT modes, curtail plant output, switch capacitor banks, and control battery dispatch. The level of remote control varies by plant design and operator authority.
Reporting and analysis: Generating reports for stakeholders (asset managers, lenders, regulators). Daily, monthly, and annual performance reports. Custom queries for specific analysis. Integration with enterprise asset management systems.
Typical SCADA architecture
A solar plant SCADA system has several layers.
Field devices: Inverters, meters, sensors, pyranometers, switchgear. These are the sources of data and the targets of control commands.
RTUs (Remote Terminal Units) or IEDs (Intelligent Electronic Devices): Local intelligence that polls field devices, applies basic logic, and communicates with the central SCADA server.
Communication network: Industrial Ethernet, fibre optic links, sometimes wireless for outdoor weather stations. Protocols include Modbus TCP, OPC UA, IEC 61850 for substations.
SCADA server: Central server running the SCADA software, hosting the historian database, and managing the user interface.
Workstations: Operator terminals running the SCADA client software for visualisation and control.
Cybersecurity layer: Firewalls, encryption, access controls protecting the SCADA system from unauthorised access.
Integration interfaces: Connections to enterprise systems, regulatory reporting, grid operators, and third-party analytics platforms.
For larger plants, the SCADA system is itself distributed, with redundant servers and failover capability.
SCADA features for solar
A modern solar SCADA system typically includes:
Real-time plant overview with key performance metrics.
Inverter-level dashboards showing per-inverter generation and faults.
String-level monitoring catching individual string failures.
Weather data integration with plane-of-array irradiance, ambient and module temperatures.
Performance Ratio (PR) calculation in real-time and historical.
Availability tracking with alarm logs.
Energy reporting in standard formats (daily, monthly, annual).
Alarm management with priority levels and acknowledgement workflows.
Remote control for power factor, reactive power, and curtailment.
Historical data storage and trending.
Configurable user roles with access controls.
Integration with predictive maintenance and asset management tools.
Mobile dashboards for on-the-go monitoring.
SCADA in Indian solar landscape
Major SCADA platforms used in Indian solar:
Schneider Electric Wonderware (now AVEVA): Long-established industrial SCADA, used in many large solar plants.
ABB Symphony Plus: Used in larger utility solar projects.
Siemens WinCC: Standard option in some commercial and industrial plants.
GE Predix: Cloud-based, increasingly used for distributed and rooftop fleet management.
Inverter-integrated platforms: Sungrow iSolarCloud, Huawei FusionSolar, SMA Sunny Portal. These vendor platforms manage inverter-side data; many plants combine them with broader SCADA for full plant visibility.
Indian players: Statcon Energiaa, Larsen and Toubro Construction’s solar monitoring, Tata Power Solar Systems. These offer integrated SCADA solutions tailored to Indian solar.
For typical utility-scale plant in India, the SCADA system is procured as part of the EPC scope, with the chosen platform depending on the lead engineer’s experience and equipment compatibility.
SCADA and grid operator integration
Indian grid operators (POSOCO, NLDC, state SLDCs) increasingly require real-time data from solar plants for system balancing and frequency management. The required data includes:
Real-time MW generation.
Voltage and frequency at plant connection point.
Availability status.
Forecast generation for next 24 hours.
The SCADA system includes interfaces (typically IEC 61850 or specific protocols required by the grid operator) to transmit this data to the grid control centre.
Compliance with grid code requirements for renewable energy integration is now a standard requirement for new solar plants.
SCADA cybersecurity
Solar plants are critical infrastructure. Cybersecurity in SCADA is increasingly important:
Network segmentation: Separating SCADA networks from corporate IT networks.
Access controls: User authentication with multi-factor where applicable.
Encryption: Securing data in transit and at rest.
Audit logs: Recording all control actions and access events.
Patch management: Keeping software and firmware up to date.
Threat detection: Monitoring for unauthorised access or anomalous behaviour.
CERT-In (Indian Computer Emergency Response Team) and CEA guidelines on cybersecurity for power utilities apply to solar plant SCADA systems.
Common SCADA mistakes
Treating SCADA as a procurement afterthought. Plant operations depend on SCADA; under-investment causes long-term costs.
Mixing incompatible equipment without communication planning. Modbus addresses, protocol versions, and data formats all need coordination.
Poor cybersecurity. Remote SCADA access without proper controls creates risk.
Inadequate operator training. SCADA’s value depends on operators using it effectively.
Not maintaining historian databases. Long-term data loss prevents trend analysis and forensic investigation.
Skipping SCADA integration with O&M workflows. Standalone SCADA is less valuable than integrated O&M.
Best practices
For plant design, specify SCADA architecture early. Coordinate with equipment vendors on protocols, data points, and communication.
For utility-scale plants, use redundant SCADA architecture with hot standby servers.
For O&M, integrate SCADA with predictive maintenance tools and CMMS (Computerised Maintenance Management System).
For cybersecurity, follow CERT-In and CEA guidelines. Conduct annual security audits.
For data retention, maintain historian for at least the plant’s full operating life (25+ years).
For grid integration, validate SCADA’s compliance with state grid code requirements before commissioning.
Standards and references
SCADA in solar follows IEC 61724-1 for performance monitoring. Communication protocols include Modbus, OPC UA, IEC 61850, and IEC 60870. Cybersecurity guidelines from CERT-In and CEA apply. International best practices from IEEE and IEC inform plant design.
Related glossary terms
Key takeaways
SCADA (Supervisory Control and Data Acquisition) is the computer-based system that monitors and controls solar plants in real-time. It collects data from inverters, meters, weather stations, and switchgear, displays it on operator dashboards, and supports remote control of plant operations. For utility-scale Indian solar plants, SCADA is essential infrastructure. Major platforms include Schneider Electric, ABB, Siemens, and inverter-integrated solutions from Sungrow, Huawei, and SMA. Cybersecurity, operator training, and integration with O&M workflows are critical for realising SCADA’s full value.