Solutions — Photovoltaic
Photovoltaic plant monitoring, string by string
Carmilla collects inverter, junction box and solarimeter data over Modbus, aligns it to the quarter hour and keeps it per plant: production per string, irradiance and temperatures, with sensor validity checked.
01 — What it solves
The detail you need to understand a drop
Currents, voltages and power per string
Inverters deliver per-string values, the quarter energy and the totaliser: a production drop is located, not guessed.
Sensors with verified validity
The solarimeter temperature is served with a plausibility flag (physical range and probe status): a spurious reading does not make it into the charts.
Per-plant history
Plant as anchor and typed members: junction boxes, solarimeters and inverters register themselves and the history stays ordered per plant.
02 — How it works
How monitoring works
01
Modbus readers in the field
A node at the plant polls inverters, junction boxes and the solarimeter over Modbus every few seconds and averages to the quarter hour.
02
Secure delivery
Quarter-hour samples travel to the platform through a VPN, per device class.
03
Registration and archive
Each member registers by Modbus port and address under its plant; data stays raw, scaling is applied at read time.
04
Data and API
Plant and member registries, 15-minute series per junction box, solarimeter and inverter through the API.
03 — Specifications
Under the hood
- Plant members
- Junction boxes (temperatures, voltage, per-channel currents), solarimeters (irradiance, temperature, status), inverters
- Inverters
- Per-string currents, voltages and power, temperatures, quarter and total energy; ZCS and Ingeteam in the field
- Data
- 15-minute series per member; plant parameters (nominal kWp, module area, temperature coefficient, availability thresholds)
- Integration
- REST API /v1/photovoltaic: plants, members per class, data series per member
04 — Regulation and obligations
Measuring production: incentives and performance
IEC 61724-1
Performance monitoring of photovoltaic systems: it defines the quantities to measure (irradiance, temperatures, energy) and the monitoring classes. The plant-members model follows this approach.
Italian D.Lgs. 199/2021 and DM 414/2023 — CACER
Energy communities and self-consumption: the incentive is computed on shared energy, hence on measured production and hourly meter data.
ARERA, Resolution 727/2022/R/eel — TIAD
Rules for collective self-consumption: measurement of injected and withdrawn energy for every connection point of the configuration.
GSE obligations for incentivised plants
Plants under Conto Energia and FER schemes have measurement and reporting obligations on produced energy: a consistent, browsable history per plant turns audits into a reading exercise.
Indicative references, current at publication date: they do not replace a regulatory check for your case.
05 — Frequently asked questions
Frequently asked questions on photovoltaic monitoring
Which inverters are supported?
Inverters readable over Modbus: ZCS and Ingeteam in the field today. Junction boxes and solarimeters (SUNMETER 2 PRO) complete the plant.
How do you avoid bogus sensor readings?
Every solarimeter sample is served with a validity flag: temperature within the physical range and PT100 probe reported OK. Consumers discard invalid samples.
Do you compute the Performance Ratio?
Not yet: the plant parameters are there, but the PR definition has to be agreed with the customer before exposing it as an indicator.
Can I bring the data into my O&M portal?
Yes, through the REST API with per-tenant tokens: plants, members and 15-minute series as JSON.