Municipalities
All buildings under one account, monthly and annual reports and input for energy management reports.
Energy distribution network
All your energy in one place.
PV systems, heat pumps, batteries and metering from all your sites. Monitor and control them from one portal – wherever they are.
Who it is for
One portal for everyone who works with energy
Home and PV owners
Production, consumption and battery state in one place, heat pump control from anywhere.
Installers
All installations on a map, remote diagnostics and fewer technician call-outs.
Device manufacturers
How devices behave in real operation and a direct link to service teams.
Energy communities
Energy sharing and groups of sources and loads.
How it works
- 01
Connect your devices
PV systems, heat pumps, batteries, chargers and meters from different manufacturers.
- 02
Monitor and control
Minute-level data and remote settings for PV output, batteries and heat pumps.
- 03
Evaluate
Monthly and annual reports, data export and input for energy management.
Supported devices
- Sunnycold Airsun
- Tecomat Foxtrot
- Victron Energy
- Solax
- Huawei
- SolarEdge
- Growatt
- Sigen
- Deye
- Sermatec
And other devices via Modbus TCP, MQTT or API.
On your phone: app.onlinewatt.com works in your phone’s browser. On Android, add it to your home screen in Chrome (Menu ⋮ → Add to Home screen) and open it like an app.
Data and security
- Operating data belong to the customer
- Encrypted data transfer
- Regular backups in Europe
- Integrations, including AI, can be switched off in the portal
Video and tutorials
See how onlineWatt works
FAQ
Frequently asked questions
What is onlineWatt?
onlineWatt is a cloud platform for monitoring, control, remote service and energy management. It brings PV systems, heat pumps, batteries, EV chargers and metering from all your sites into one overview at app.onlinewatt.com.
Who is onlineWatt for?
For municipalities, owners of homes and PV plants, installers, device manufacturers and energy communities. Municipalities have all their buildings under one account, installers monitor their customers’ installations.
Which devices does onlineWatt support?
Natively Sunnycold Airsun devices (PV and heat pumps) and Tecomat Foxtrot PLCs. Also inverters and batteries from Victron Energy, Solax, Huawei, SolarEdge, Growatt, Sigen, Deye, Sermatec and other devices via Modbus TCP, MQTT or API.
Can I control devices remotely?
Yes. Depending on the device, you can set PV output, battery mode, grid feed-in limits and heat pump temperature or mode. Only users with the right permission can control devices.
How does energy sharing between sites work?
Surplus energy from one site is credited to another, for example from a house to a cottage or from a school to a sports hall. In the Czech Republic, sharing is settled through the distribution system operator and the Electricity Data Centre (EDC), regardless of distance. onlineWatt shows production and consumption of all sites in one overview.
Does onlineWatt help municipalities with energy management?
Yes. The portal prepares monthly and annual consumption reports for each building and the whole town, and input for the energy management report under the methodology of the Czech State Environmental Fund (SFŽP), including the source of each reading.
Who owns the data and how is it secured?
Operating data belong to the customer and can be exported at any time. Devices send data encrypted (MQTT 5.0 with SSL/TLS or HTTPS), access is controlled by user accounts and permissions, and data are backed up regularly to servers in Europe.
Does onlineWatt use artificial intelligence?
Yes, to analyse operating data for device manufacturers and to help installers prepare for service visits. The AI receives only device serial numbers and measured data, no names or contact details. You can switch off integrations, including AI, in the portal.
Is there a mobile app?
The portal works in the browser on your computer and phone. On Android, add it to your home screen in Chrome (Menu → Add to Home screen) and open it like an app.
How do I sign up and what does it cost?
Customers sign up at app.onlinewatt.com/customer/register, installers at app.onlinewatt.com/installation-company/register. The price depends on the features, data resolution and length of history; for municipalities we offer contract tariffs. Write to us at info@onlinewatt.com.