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Energy/
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Solar power plantsSolar power plants, measured to the performance ratio.
A solar plant’s value is its energy yield, and its yield is judged against the sunlight it received. Monitoring to recognised classes measures irradiance in the plane of the modules, module temperature, soiling and weather beside inverter and meter output, so owners, lenders and operators share one performance figure they can trust, and faults show up before they cost a season.
Plan a deploymentHow it worksStation Builder- Industry
- Energy
- Measurements
- 5
- Sources cited
- 3
Energy · Solar power plants
A plant judged against the sun
A solar plant is judged by how much of the sunlight it received became energy at the meter. Get the sunlight measurement wrong and performance is misjudged; miss soiling, string faults or an inverter outage and yield leaks away quietly. Observation makes both sides of that comparison trustworthy.
What is measured
Sunlight, heat, dust and output
Pyranometers and reference cells measure irradiance in the plane of the array and on the horizontal; sensors on the back of modules measure temperature; soiling stations measure dust losses; a weather station records wind, temperature and rain; inverters and the revenue meter report output.
- Instruments
- Pyranometers · Reference cells · Module temperature · Soiling · Weather · Meters
The base node
A node that computes performance
An industrial gateway reads irradiance, weather and meter data; cameras connect directly. The plant node signs every value, computes the performance ratio and expected yield from measured sunlight and temperature, flags what falls behind and keeps the record during outages.
Radio and links
Fibre inside, cellular out
Fibre laid with the plant’s cables joins inverter stations and the substation. A cellular link carries the plant’s record to the operator, battery sensors on far rows report over LoRaWAN, and satellite serves plants beyond public coverage. The choice comes from the survey.
- Links
- Fibre · Public cellular · LoRaWAN · Satellite
How it works
From a pyranometer to a performance ratio
A pyranometer’s signal is read by the gateway, combined on the node with module temperature and meter output, signed and stored. Each interval adds to the plant’s expected and actual yield, and each month becomes a report that owners and lenders read the same way.
From order to operation · Order
Scope the plant and the method
The scope agrees the monitoring class, the performance method and the reports owners and lenders need. Nexus Observatory Inc. returns the station plan, the integration with inverters and meters, the radio approach and a price per plant and per service.
Plan a deploymentFrom order to operation · Survey
Survey rows, inverters and the substation
Crews walk the plant with the operator, choosing representative positions for irradiance, temperature and soiling, checking inverter and meter interfaces, cable routes and coverage, and recording each position against the plant layout. Shading from terrain, trees and buildings is checked at each candidate position, so stations represent the plant rather than one corner of it.
From order to operation · Permits
Work within the plant’s safety rules
Work near energised equipment follows the plant’s electrical safety rules and isolation procedures. Integration with inverters and the revenue meter is agreed with their owners, and data sharing with lenders and grid operators follows the contracts. Every agreement is kept with the plant’s record.
From order to operation · Build
Build calibrated stations
Irradiance and weather stations are built with calibrated sensors and their certificates, gateways are configured for the plant’s inverters and meters and the node is tested with recorded data. Each device is enrolled with its identity and position. Calibration certificates travel with each sensor into the record.
Open the Station BuilderFrom order to operation · Install
Install and align
Stations are installed on their mounts, pyranometers levelled or aligned to the plane of the array, module sensors bonded to the back of modules, soiling stations set beside representative rows and gateways connected to inverters and meters. Each installation is photographed.
From order to operation · Commission
Commission the performance figure
Each node proves its identity; sensors are checked against their certificates and against each other; inverter and meter data are compared with their own displays. The performance calculation is run on the first days of data and reviewed with the owner.
From order to operation · Operate
Yield, losses and alerts
The console shows performance ratio, expected against actual yield, soiling losses and underperforming strings and inverters. Alerts arrive with their data, and monthly performance reports go to owners and lenders. Losses are split into soiling, availability and equipment faults, so each team knows which loss is theirs to recover.
From order to operation · Maintain
Recalibrate and clean on evidence
Sensors are cleaned and recalibrated on schedule, and cleaning of modules is scheduled from measured soiling. Software moves in rings, and every change is recorded so performance stays comparable from year to year. Recalibration dates and results are kept with each sensor, so any shift in the series can be explained.
Book field servicesData products
One performance figure for everyone
Owners and lenders see performance ratio and yield; operations teams see losses from soiling, availability and faults; technicians receive alerts for strings and inverters that fall behind; grid operators can use measured irradiance in forecasts. All read the same calibrated, signed data.
See the data productsEvidence
A performance method that holds up
Sensor certificates, alignment and calibration records, every alert and every report are signed and kept. Monitoring follows the international photovoltaic performance monitoring standard at the class agreed, so a lender’s engineer can verify the performance figure from the raw measurements.
- Drawn against
- IEC 61724-1 · IEEE 1547
What you get
Sensing as a Service
Observation networks designed, installed, operated and maintained for a monthly fee: weather, hydromet, air, seismic and environmental stations, with data delivered under a licence. Delivered as managed service and data licence, for agencies, utilities, municipalities, insurers, agribusiness. Scale: Global, multi-site, per-site pricing.
Talk to salesNext step
Plan solar power plants with us
Tell us the site, the measurements and the rules it answers to. We reply with a survey proposal, a design and a scope for solar power plants. An engineer replies with a survey proposal and a scope, and the plan grows from one site to the network you need, at your pace.
Plan a deploymentOpen the Station BuilderOpen the Studio
01The place and its hazards
Where it runs, and what can go wrong.
Operating contextUtility-scale and commercial solar plants spread rows of modules over large areas, convert power in inverters and export through a substation. Their performance ratio compares delivered energy with the energy the measured sunlight should have produced, so the quality of the irradiance measurement decides how performance is judged. Soiling, shading, inverter faults and string failures erode yield quietly.
Hazards
- Undetected loss of yield from soiling, string faults or inverter outages
- Poor irradiance measurement that misjudges performance
- Hail, wind and flood damage
- Fire in combiner boxes, inverters and batteries
- Theft and intrusion on large unattended sites
02What must be measured
What, where, how often, and under which rules.
Each measurement names where it is taken, how often, and the public standard or regulation behind it. Numbers in the sources column open the cited source below.
| Measurement | Where | Cadence | Sources |
|---|---|---|---|
| Irradiance in the plane of the array and on the horizontal | Pyranometers and reference cells at representative positions | Continuous, at the interval of the monitoring class chosen | 1 |
| Module temperature | Back-of-module sensors across the plant | Continuous | 1 |
| Soiling | Soiling stations or paired reference devices | Continuous | 1 |
| Inverter and meter output | Inverters, combiner boxes and the revenue meter | Continuous | 12 |
| Wind, temperature and rain | Plant weather station | Continuous | 3 |
03The observation stack
From one base unit to a network.
The same blocks at every scale: instruments and a base node, a site with its radio, a fleet run as one, and a network federated on the open protocol.
- 01
Base unit
A weather and irradiance station read through an industrial gateway, and a node that signs every value and computes performance.
Build a station → - 02
Site
A plant: irradiance, module temperature and soiling stations, inverter and meter data, and cameras, joined to the plant node.
Plan a site → - 03
Fleet
Every plant of a portfolio run as one fleet, with one performance method and one record.
Managed offers → - 04
Network
Owners, lenders, operators and grid operators read federated records, each with the access their role gives them.
The open protocol →
- 01Compact weather station
- 02Energy and power-quality meter
- 03Fixed camera
- 04OT gateway (OPC UA, Modbus)
- 05Edge node (Wedge)
- 06Cellular modem/router
- 07Battery case
- 08Pole
Radio and links
Fibre
Fibre laid with the plant’s cables joins inverter stations and the substation inside the site.
Radio and links
Public cellular
Most plants are reachable by public networks; a cellular link carries the plant’s record to the operator.
Radio and links
LoRaWAN
Battery sensors on far rows report module temperature and soiling without new cable.
Radio and links
Satellite
Remote plants beyond public coverage use satellite backhaul.
Edge computeThe plant node computes performance ratio and expected yield from measured irradiance and temperature, flags strings and inverters that fall behind and keeps the record during outages.
PowerStations take auxiliary power with battery backup, so measurement continues through grid outages and night-time maintenance.
04How it works
From the instrument to the product.
One observation’s path, tier by tier, with the interface on every link and a bill of materials below; then how the one node grows to a site, a fleet and federated networks.
Solar power plants: data path
– of 07
01 Instruments Measurement with sensor identity andcalibration 02 Gateway 03 Node – Wrap in an observation envelope with timequality– Measure quality and uncertainty, attachquality flags– Buffer locally (store-and-forward when thelink drops) 04 Backhaul Commit with transactional outbox andpublish, delivered at least once 05 Site Consumer inbox deduplicates and applieseach record once into governed data 06 Data store Governed product through API, map orexport, correction-aware 07 Products IEC 61724-1OPC UA (IEC 62541)Modbus 08 Power and structure Supplies 12 V DC, 24 V DC, 48 V DC to thefield equipment Pyranometers and reference cells Not in the reference kit 01 Compact weather station SDI-12 · RS-485 · Ethernet 02 Energy and power-quality meter SDI-12 · RS-485 · Ethernet 03 Fixed camera Ethernet 04 OT gateway (OPC UA, Modbus) Ethernet · RS-485 · CAN · AnalogueI/O 05 Edge node (Wedge) Ethernet · Fibre · USB · RS-485 ·BMC 06 Cellular modem/router Ethernet · USB · RS-232 Site MQTT 5 with Sparkplug B Governed data store Versioned, correction-aware Performance ratio and expected yield Loss analysis: soiling, availability andfaults Alerts for underperforming stringsand inverters Monthly performance reports 07 Battery case USB 08 Pole Analogue I/O RS-485 · Modbus RS-485 · Modbus Ethernet · RTSP/ONVIF Ethernet · opc-ua Ethernet LTE/NR| Item | Equipment | Data ports | Protocols | Power in |
|---|---|---|---|---|
| 01 | Compact weather stationAll-in-one or compact station for temperature, humidity, pressure, wind and rain at a site. | SDI-12RS-485Ethernet | SDI-12, Modbus, MQTT 5, OGC SensorThings API | 12 V DC |
| 02 | Energy and power-quality meterMeter for voltage, current, power, energy and power quality at a site or on a feeder. | SDI-12RS-485Ethernet | Modbus, IEC 61850 (MMS, GOOSE), DNP3 (IEEE 1815), MQTT 5 | 12 V DC |
| 03 | Fixed cameraFixed visible-light camera for site security, scene monitoring and machine vision. | Ethernet | RTSP with ONVIF profiles, MQTT 5 | PoE |
| 04 | OT gateway (OPC UA, Modbus)Read-only bridge from industrial fieldbuses and controllers (Modbus, OPC UA, DNP3, IEC 61850, CAN) to the site network, behind a security boundary. | EthernetRS-485CANAnalogue I/O | OPC UA, Modbus, DNP3 (IEEE 1815), IEC 61850 (MMS, GOOSE), MQTT 5 | 24 V DC |
| 05 | Edge node (Wedge)Rugged edge node that boots from signed media, attests itself and establishes a site cell from little or no infrastructure. | EthernetFibreUSBRS-485BMC | MQTT 5, DMTF Redfish, IEEE 1588 PTP, NTP with NTS, OPC UA | 12 V DC, 24 V DC, 48 V DC, AC mains |
| 06 | Cellular modem/routerLTE or NR modem or router that uses a public carrier or private network as backhaul. | EthernetUSBRS-232 | 3GPP E-UTRA air interface, 3GPP NR air interface, OMA LwM2M | 12 V DC, PoE |
| 07 | Battery casePortable battery pack with DC outputs for field kits. | USB | Modbus | AC mains, HV DC, USB PD |
| 08 | PoleUtility, street or dedicated pole with clamp positions. | — | — | — |
How it scales
01 Instruments Arbitrary qualified sensors and instruments whosemeasurements are ingested with calibration, units,geometry, time, custody and uncertainty. ×n 02 Node The minimum useful deployable unit: server, ruggedappliance, radio node, sensor gateway, satelliteterminal, AI, scientific, vehicle or virtual node. Node Node agent 03 Site The minimum independently operable localgovernance and failure domain: one or more nodesplus local network, identity, policy, evidence,storage, products and operator surfaces.SITE
Node Node Node ×n 04 Cluster An optional scale or specialisation domain forscheduling, shared storage, accelerators or datalocality.CLUSTER
×n 05 Fleet Coordinates plans, acknowledgements,convergence evidence, update campaigns andcorrection propagation across nodes and sites.FLEET
Fleet controller ×n 06 Federation An exchange of products, capabilities, events orwork across approved, independently administeredtrust domains, using explicit trust, policy,data-locality, version and correction contracts.TRUST DOMAIN
TRUST DOMAIN
TRUST DOMAIN
×n Verifier Applications Data in the field Telemetry Control Data upstream Control Data upstream Control Exchange Evidence Events Exchange- Data in the field
- MQTT 5 with Sparkplug B; connectors for LoRaWAN, OPC UA and instrument buses.
- Telemetry
- OpenTelemetry OTLP.
- Control
- TLS 1.3 with mutual authentication; protobuf messages over gRPC or HTTP/2.
- Data upstream
- At-least-once publication with repeat-safe keys over the control channel or NATS JetStream; QUIC MAY be used on lossy links.
- Evidence
- DSSE-signed in-toto statements; SLSA provenance; SCITT transparency receipts.
- Events
- Event envelopes mapped to CloudEvents 1.0; channels described in AsyncAPI 3.
- Exchange
- OpenAPI 3.1; the OGC API family; SensorThings; STAC; WIS 2.0.
05From order to operation
Every step, from the first call to a running site.
The same crew and the same record carry the work from scope to maintenance.
- 01 Order
Scope the plant and the method
The scope agrees the monitoring class, the performance method and the reports owners and lenders need. Nexus Observatory Inc. returns the station plan, the integration with inverters and meters, the radio approach and a price per plant and per service. 1
- 02 Survey
Survey rows, inverters and the substation
Crews walk the plant with the operator, choosing representative positions for irradiance, temperature and soiling, checking inverter and meter interfaces, cable routes and coverage, and recording each position against the plant layout. Shading from terrain, trees and buildings is checked at each candidate position, so stations represent the plant rather than one corner of it.
- 03 Permits
Work within the plant’s safety rules
Work near energised equipment follows the plant’s electrical safety rules and isolation procedures. Integration with inverters and the revenue meter is agreed with their owners, and data sharing with lenders and grid operators follows the contracts. Every agreement is kept with the plant’s record.
- 04 Build
Build calibrated stations
Irradiance and weather stations are built with calibrated sensors and their certificates, gateways are configured for the plant’s inverters and meters and the node is tested with recorded data. Each device is enrolled with its identity and position. Calibration certificates travel with each sensor into the record.
- 05 Install
Install and align
Stations are installed on their mounts, pyranometers levelled or aligned to the plane of the array, module sensors bonded to the back of modules, soiling stations set beside representative rows and gateways connected to inverters and meters. Each installation is photographed.
- 06 Commission
Commission the performance figure
Each node proves its identity; sensors are checked against their certificates and against each other; inverter and meter data are compared with their own displays. The performance calculation is run on the first days of data and reviewed with the owner.
- 07 Operate
Yield, losses and alerts
The console shows performance ratio, expected against actual yield, soiling losses and underperforming strings and inverters. Alerts arrive with their data, and monthly performance reports go to owners and lenders. Losses are split into soiling, availability and equipment faults, so each team knows which loss is theirs to recover.
- 08 Maintain
Recalibrate and clean on evidence
Sensors are cleaned and recalibrated on schedule, and cleaning of modules is scheduled from measured soiling. Software moves in rings, and every change is recorded so performance stays comparable from year to year. Recalibration dates and results are kept with each sensor, so any shift in the series can be explained.
06Data products and integration
What it delivers, to whom, and into which systems.
Data products
- Performance ratio and expected yieldOwners, asset managers and lenders
- Loss analysis: soiling, availability and faultsOperations and maintenance teams
- Alerts for underperforming strings and invertersField technicians
- Monthly performance reportsOwners and lenders’ engineers
Integration
- Plant SCADA and invertersInverter and meter data are read over Modbus and the plant SCADA’s interfaces.
- Asset managementPerformance and loss figures feed the owner’s asset management platform.
- Grid operatorMeasured irradiance supports the forecasts the plant provides to the grid operator.
Exchanged through IEC 61724-1, OPC UA (IEC 62541), Modbus.
07Questions buyers ask
Before you scope it.
Which monitoring class do we need?
That depends on the plant’s size and what lenders require; the plan states the class chosen and why.
Can you use our existing weather station?
Yes, if its sensors meet the chosen class; otherwise the plan adds what is missing.
How is soiling measured?
With soiling stations or paired clean and soiled reference devices, so cleaning is scheduled on evidence.
Can we monitor a whole portfolio the same way?
Yes. Every plant uses the same method, so performance compares across the portfolio.
08Resources
The sources behind this page.
Public standards, regulations and guidance, cited where they apply. Each applies only where its jurisdiction or scope does.
- 1IEC 61724-1: Photovoltaic system performance, monitoringInternational Electrotechnical Commission
- 2IEEE 1547: Interconnection and interoperability of distributed energy resourcesIEEE Standards Association
- 3Guide to Instruments and Methods of Observation (WMO-No. 8)World Meteorological Organization
09Related
Use cases and solutions.
Use caseBankable solar and wind resource station
A met mast or lidar with secondary-standard pyranometers and a traceable calibration chain, for a measurement campaign lenders accept.The full use case →SolutionSensing as a Service
Observation networks designed, installed, operated and maintained for a monthly fee: weather, hydromet, air, seismic and environmental stations, with data delivered under a licence.Solutions for energy →SolutionPrivate and federated observing grids
Design and operation of an organisation’s own grid on the open protocol, with provider admission, device qualification and federation across trust domains.Solutions for energy →SolutionMicrogrids and off-grid site power
PV, storage and generator sizing for instruments and edge sites, with telemetry and remote control.Solutions for energy →10Energy: specialized fields
Other fields of this industry.
Specialized fieldUpstream oil and gas
Methane detection and quantification at wellpads and facilities, flare and tank monitoring, wellhead flow and pressure, on satellite and private links for sites with no one on them.The full field →Specialized fieldPipelines and midstream
Leak detection, cathodic protection, pressure and flow along the line, geohazards at crossings and compressor and pump stations, on LoRaWAN, satellite and private links over hundreds of kilometres.The full field →Specialized fieldThermal power plants
Continuous emissions, machine condition, cooling water and plant weather for gas, coal and biomass plants, with an industrial network that keeps the control system separate and secure.The full field →Specialized fieldHydropower and dams
Dam safety instruments, reservoir and river levels, inflow forecasting and downstream warning, with links that keep working in the flood the dam is there to hold.The full field →Specialized fieldWind farms
Wind resource and power performance, turbine condition, icing, lightning and wildlife monitoring, from the first met mast to an operating farm on one record.The full field →Specialized fieldTransmission networks
Line ratings from measured weather and conductor state, wildfire and vegetation watch, substation automation and synchrophasor timing, on private LTE, microwave and fibre along the corridor.The full field →Specialized fieldDistribution networks and the grid edge
Feeder and transformer monitoring, distributed energy resources, fault location and outage evidence, on a utility private network that reaches every pole and substation.The full field →Bring us the site.
Plan a deployment, configure a station, model it in the Studio or talk to sales. The form names who receives your details.
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