What does DAS stand for in solar?

DAS stands for data acquisition system. In solar it is the equipment and software that polls inverters, meters, weather sensors, and trackers on a fixed interval, timestamps each reading, and stores the record. The DAS is the source of truth that monitoring portals, utilities, incentive programs, and warranty claims all draw from.

Is a solar DAS the same as solar monitoring?

No. The DAS collects and stores the data; a monitoring portal displays and analyzes it. Many products bundle the two, which is convenient until you need the raw record for a dispute. Ask whether you own the interval data and can export it, independent of the portal.

What sampling interval does a solar DAS need?

Programs such as SGIP accept logging at 15 minute intervals, which is enough to compute incentives. Diagnosing a fault, a clipping event, or a tracker stall needs seconds. A good DAS samples at seconds and aggregates to whatever interval the program or the financier requires, while keeping the fine data for engineering.

Does a DAS need a weather station?

For performance verification, yes. Production alone tells you what the plant made; irradiance and module temperature tell you what it should have made. Performance ratio, weather normalized KPIs, and most warranty claims depend on a site irradiance sensor. A satellite estimate is a fallback, not a substitute.

Who requires a DAS on a commercial solar project?

Utilities and ISOs require telemetry under the interconnection agreement. Incentive programs such as California SGIP require an approved performance data provider for at least five years with 15 minute data. Lenders and offtakers require it to verify performance guarantees. In practice almost every project above residential scale needs one.

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What Is a DAS in Solar?

A solar DAS (data acquisition system) is the hardware and software that polls every device on a photovoltaic site, such as inverters, meters, weather stations, and trackers, and records their readings on a fixed interval with a trustworthy timestamp. It is the source of record for production, availability, and performance ratio, and it feeds the monitoring portal, the utility, and the incentive program above it.

By Eric Hinckley, Chief Technology OfficerPublished September 2, 2026

Key takeaways

A DAS collects and stores; a monitoring portal displays and analyzes; SCADA supervises and controls.
The devices that matter are inverters, revenue meters, irradiance and temperature sensors, and trackers, each read on its own protocol.
Modbus is the common device protocol, SunSpec standardizes the Modbus register maps, and DNP3 carries data to utilities.
Resolution decides what you can see: SGIP accepts 15 minute logging, but string faults, clipping, and tracker stalls show up at seconds.
Financiers, utilities, and programs such as SGIP require a DAS because performance payments and warranty claims depend on its data.

What devices does a solar DAS poll?

Four device classes carry almost all of the information an owner needs.

Inverters, string or central: AC and DC power, voltage and current per input, energy totals, temperature, and fault codes.
Meters: a revenue grade meter at the point of interconnection, plus generation and consumption meters where the tariff or program requires them. SGIP requires interval data recording meters accurate to plus or minus 2 percent and tested to ANSI C12 on projects 30 kW and larger.
Weather stations: plane of array and global horizontal irradiance, ambient and module temperature, and wind speed.
Trackers: commanded versus actual angle, motor status, stow and backtracking events, and communication faults.

What protocols does a solar DAS speak?

Most site devices expose Modbus, either serial Modbus RTU over RS485 or Modbus TCP over Ethernet. The Modbus Organization describes it as the most widely adopted industrial communication protocol, and its register model is simple enough that almost every inverter, meter, and weather logger supports it, though every vendor lays out its registers differently.

SunSpec Modbus solves the layout problem. The SunSpec Alliance publishes information models that define common parameters for inverters, batteries, meters, string combiners, trackers, and metrology stations, so a DAS can read a conforming device without a custom map. SunSpec also publishes an IEEE 1547 profile and notes that SunSpec Modbus is specified in the national grid codes of the United States, Canada, Denmark, and Poland.

DNP3 is the protocol the utility side expects. The DNP Users Group describes it as an open protocol built for substations and SCADA, standardized as IEEE 1815 in 2010, with IEEE 1815.2 added for distributed energy resources. A DAS that reports to a utility typically speaks DNP3 outbound while it polls Modbus inbound.

Why does sampling resolution matter?

Resolution determines which problems you can see. A 15 minute average hides a five minute inverter restart, a clipping event that lasts a cloud edge, and a tracker that stalls and recovers. IEC 61724 Part 1, the international standard for PV performance monitoring, defines monitoring classes because different decisions require different fidelity.

The SGIP handbook requires meters that log no less frequently than every 15 minutes and performance data reported in 15 minute intervals. That is a floor, not a target: a DAS should sample at seconds and aggregate to whatever the program needs. Resolution is also worthless if the record has gaps, so the DAS must keep logging through a network outage and forward the stored data with original timestamps. SGIP requires meters to retain seven days of data through a power outage.

How is a DAS different from a monitoring portal or SCADA?

These three terms get used interchangeably. The DAS is the collection layer. The portal is the presentation and analysis layer on top of it. SCADA is the supervisory layer that can also write commands to equipment, which a DAS by definition does not.

DAS, monitoring portal, and SCADA compared
System	Job	Writes to devices?	Typical user
DAS	Poll devices, timestamp, store, forward	No	Owner, O&M provider, data provider
Monitoring portal	Dashboards, alerts, KPIs, reports	No	Asset manager, investor
SCADA	Supervise, alarm, HMI, relay utility commands	Yes	Plant operator, utility

Who requires a solar DAS?

Three parties, for three reasons. Utilities and ISOs need production telemetry to run the grid; the Department of Energy notes that operators need live data on how much electricity solar systems are generating to keep the system reliable, and interconnection agreements make that a condition of operation.

Incentive programs need verified performance. California SGIP requires projects subject to performance based incentives to contract with an approved performance data provider for a minimum of five years and to submit 15 minute charge, discharge, and cycling data monthly through the program portal. Nonresidential storage must show a greenhouse gas reduction of at least five kilograms of CO2 per kWh of rated capacity each year, which can only be proven with interval data.

Financiers and offtakers need proof the plant performs. A power purchase agreement, a performance guarantee, and an inverter warranty all resolve to the same question: did the site produce what the irradiance said it should? The DAS record answers it.

How does a DAS support performance ratio and availability?

Performance ratio compares actual energy to the energy the array should have produced at the measured irradiance, normalized to nameplate. Sandia’s PV Performance Modeling Collaborative lists performance ratio, performance index, and normalized efficiency among the standard metrics and documents the plane of array irradiance methods they depend on. The DAS supplies both halves of the ratio: metered energy and coincident irradiance from the site sensor.

Availability is the fraction of time the equipment could produce when there was resource to produce from. Computing it requires inverter status at fine resolution, irradiance to know when daylight counted, and clean timestamps to align the two.

What should you look for in a solar DAS?

Ask for sampling at seconds with aggregation to program intervals, store and forward logging that survives an outage, native Modbus and DNP3 with SunSpec support and configurable maps for the rest, weather station and tracker inputs, and an API so the data is yours.

WATTMORE built Intellect EnFORM to that list: ruggedized edge hardware logging at 30 second granularity with store and forward, vendor agnostic integration over Modbus RTU and TCP, DNP3, MQTT, and REST, weather station and tracker monitoring, automated performance ratio and availability reporting, and approval as an SGIP performance data provider.

Intellect EnFORM

Intellect EnFORM is a solar and storage data acquisition system with ruggedized edge logging at 30 second granularity, store and forward during outages, vendor agnostic Modbus, DNP3, MQTT, and REST integration, and automated performance ratio and availability reporting.

See Intellect EnFORM

Frequently asked questions

What does DAS stand for in solar?: DAS stands for data acquisition system. In solar it is the equipment and software that polls inverters, meters, weather sensors, and trackers on a fixed interval, timestamps each reading, and stores the record. The DAS is the source of truth that monitoring portals, utilities, incentive programs, and warranty claims all draw from.
Is a solar DAS the same as solar monitoring?: No. The DAS collects and stores the data; a monitoring portal displays and analyzes it. Many products bundle the two, which is convenient until you need the raw record for a dispute. Ask whether you own the interval data and can export it, independent of the portal.
What sampling interval does a solar DAS need?: Programs such as SGIP accept logging at 15 minute intervals, which is enough to compute incentives. Diagnosing a fault, a clipping event, or a tracker stall needs seconds. A good DAS samples at seconds and aggregates to whatever interval the program or the financier requires, while keeping the fine data for engineering.
Does a DAS need a weather station?: For performance verification, yes. Production alone tells you what the plant made; irradiance and module temperature tell you what it should have made. Performance ratio, weather normalized KPIs, and most warranty claims depend on a site irradiance sensor. A satellite estimate is a fallback, not a substitute.
Who requires a DAS on a commercial solar project?: Utilities and ISOs require telemetry under the interconnection agreement. Incentive programs such as California SGIP require an approved performance data provider for at least five years with 15 minute data. Lenders and offtakers require it to verify performance guarantees. In practice almost every project above residential scale needs one.

Sources

SunSpec Modbus, SunSpec Alliance
Overview of the DNP3 Protocol, DNP Users Group
The Modbus Organization, Modbus Organization
Self Generation Incentive Program Handbook 2025, California Public Utilities Commission
IEC 61724 Part 1: Photovoltaic System Performance, Monitoring, International Electrotechnical Commission
PV Performance Modeling Collaborative, Sandia National Laboratories