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FAQ - Solar.web APPSolar Energy

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General questions

Your Fronius user account can be used to log into any Fronius platform. You do not need to create a separate user account.
If you already have a Fronius user account, you can use it to log into the app. If not, you can do so by going to www.solarweb.com and clicking on the ‘Login’ menu item. Should you require additional help with registration, please send details of the error message you have received and the e-mail address you would like to use for your user account to our customer services. To do this, please use our contact form.
Please check that the registration process has been completed fully. After registration, a link will be sent to your e-mail address. Please open it and log in for the first time, at which point you will be asked to fill out your personal data. If you still have problems logging in, please contact our customer services using the e-mail address belonging to your user account. To do this, please use our contact form.
As a first step, please check your spam folder. If you still cannot find any such e-mail, please contact our customer services using the e-mail address belonging to your user account. To do this, please use our contact form.

Solar.web App

Please click on the plus symbol in the app. This will open the Solar.web page ‘Add PV system’ in your smartphone browser. Alternatively, you can go straight to www.solarweb.com, log in using your user data and then add your PV system. You will then be guided through the process and afterwards you can return to the app. If your system is still not displayed, please contact our customer services using the e-mail address belonging to your user account. To do this, please use our contact form.
There are many reasons why Solar.web may not be receiving data from your inverter. Please go to our PV system support page for useful tips on how to re-establish the data connection. Should you require additional help, please send details of the error message you have received and the e-mail address belonging to your user account to our customer services. To do this, please use our contact form.
There are many reasons why Solar.web may not be receiving data from your inverter. Please go to our PV system support page for useful tips on how to re-establish the data connection. Should you require additional help, please send details of the error message you have received and the e-mail address belonging to your user account to our customer services. To do this, please use our contact form.
You have ‘guest’ rights for the selected Solar.web system. In order to be able to make changes, you need the ‘supervisor’ right. The Fronius Solar.web user account, which has been granted ownership rights to the system, can grant you this authorisation. In most cases, this is your installer. 
This shows the current weather in the PV system’s location.
Yes. Click on the system name in the upper section of the app. The PV system selection menu will then open and you can then change between the PV systems. Tip: If you have access to more than five PV systems in your Solar.web user account, you can mark one PV system as your favourite by clicking on the heart symbol next to it.

Energy Cost Assitant

The energy cost assistant automatically optimizes the control of the battery based on a dynamic tariff and AI-driven forecasts. This means that if the battery is fully charged and the load is expected to be high at times when energy prices are high, it limits the discharge to use the cheaper energy for the forecast demand. If the battery does not have enough energy for the expected load, it is charged from the grid in order to obtain the required energy at the best possible price. This is done on the basis of production, load and price forecasts. Further use cases and extensions will follow shortly.
The energy cost assistant will be available in Austria from February 24.2025. Other countries will be added in the coming weeks to ensure stability and scalability.

To activate the Energy Cost Assistant, a compatible Fronius inverter (GEN24 Plus) and a compatible battery are required. Furthermore, a dynamic tariff with the energy supplier is required so that the Energy Cost Assistant can carry out the optimizations. If the country in which the system is located is supported by the Energy Cost Assistant, the owner or manager of the system will see the onboarding page in Solar.web (web portal) under Settings -> Operating mode. Here the user can see all the requirements that are necessary to use the Energy Cost Assistant.

The requirements are:

  • Solar.web Premium,
  • a dynamic tariff (support for time-of-use tariffs is planned),
  • Activation of the weather forecast for the system (included in Solar.web Premium)
  • Inverter on the latest firmware (1.34.6 or higher)
The Energy Cost Assistant supports all Fronius GEN24 Plus inverters with all compatible batteries. If a Fronius GEN24 is updated via UP.storage, it can also use the Energy Cost Assistant. If a hybrid inverter and an additional inverter are available, the Energy Cost Assistant can still be used. The Fronius Symo Hybrid is not supported for technical reasons.

After the energy cost assistant has been activated in the Solar.web portal, there is a page called "Operating mode" where users can activate and deactivate the energy cost assistant for the system. Here the user can also see the (planned) behavior of the current day and can see when the energy cost assistant will perform which checks. A diagram also helps the user to understand the behavior. This page is visible to all users with system administrator or owner rights after initial activation.



In the Solar.web app, users with owner or system maintenance rights can see the current status under the bubble chart on the dashboard to see whether the energy cost assistant is currently intervening in the system. This can be deactivated again under Settings -> Operating mode.

Sustainability is a central component at Fronius. The Energy Cost Assistant takes the degradation of the battery into account, as each charging cycle incurs indirect costs. Therefore, the Energy Cost Assistant only charges from the battery when it is necessary. Either there is not enough energy in the system for the expected load or when the energy is so cheap that it still makes financial sense after taking into account the degradation of the battery per charge. The required difference between the cheapest and most expensive electricity price is currently 16c/kWh to charge from the grid. It is planned that the user will be able to adjust this setting in the future.
A list of all compatible countries / providers / tariffs can be found at https://www.solarweb.com/Home/PremiumInfo. If the Energy Cost Wizard is available in a country, basic integration with the spot market tariff is possible. In addition, Fronius is working on cooperations with certain energy providers to provide more detailed energy prices.
If there are multiple inverters in a system, the Energy Cost Wizard must identify the correct primary inverter. The primary inverter must be the one with a battery, which must be set up as described here

Our energy balance is a visualization that has been optimized to analyze what happens with PV production or the surplus and how the load is covered. Charging from the grid has been deliberately excluded here, as this was not previously relevant in a classic self-consumption-optimizing system. The energy is counted as load when it is discharged from the battery.

Fronius is working on a new view that makes this more transparent and clearly shows when a battery is being charged from the grid. These currents can currently be tracked in the Solar.web portal in the "Energy from the grid" channel in the progression diagram.

As the energy price of the energy community can deviate from the normal dynamic tariff, the energy cost assistant would sometimes carry out actions that are not optimal. A combination of the energy cost assistant and energy communities is therefore not recommended for the time being.

For technical reasons, the AI-based production forecast used by the Energy Cost Wizard is now only available for systems that use the Energy Cost Wizard. As this is not yet available worldwide, there will be two different forecasts in the energy balance and the energy cost assistant diagram.

We are currently working on improving our AI-based forecast, which will then also be integrated into the new energy balance. The new forecast takes historical values into account and uses a new weather data provider to improve accuracy.

The energy cost assistant must first analyze the system before it can start optimizing the system. This can take a few minutes.

Yes, you can generally activate the Energy Cost Assistant – as long as it’s available in your country and the basic requirements are met.

The assistant works most effectively when there’s a price difference of at least 4 cents per kilowatt-hour (including grid fees) between expensive and cheaper electricity times. If the difference is smaller, the potential savings might not justify the additional charging cycles of your energy storage system. The Energy Cost Assistant automatically detects such situations and adjusts its behavior accordingly – for example, by intervening less frequently.

Battery Control

Battery control gives homeowners the possibility to manually prepare their system for an expected blackout. After the feature is started in the Solar.web-App, the battery is prepared and charging will start. The battery will then be charged up to max SoC (either the one set on the inverter-WebUI or 100%). When the battery is fully charged, it is locked for 24 hours. During this time, discharging is not possible, as the energy is reserved for a possible backup-situation. If the blackout occurs when the battery is full, the energy in the battery can be used to cover the consumption. After the blackout, the battery is kept locked, in case of an additional blackout afterwards. If the battery was still charging, when the blackout occurred, it will continue charging until full afterwards. If the blackout doesn´t occur, the battery is either automatically unlocked after 24 hours, or the user manually unlocks the battery in the Solar.web-App.

No, this feature is free of charge and will be available for every user with a compatible system.
No, due to technical reasons Battery control won´t be available for Symo Hybrids.
If a user has Supervisor- or Owner-permissions on a system, he/she can see & use Battery control. If the user is only guest on a system, he / she will see the status, but can´t start or stop it. Please adapt the permissions on your system in the Solar.web Portal (Settings -> Permissions) to regulate, who can use this feature.
This feature can be activated in the Solar.web-App with GEN24s Plus's, a DC-coupled battery (all supported batteries are compatible) and a smartmeter. There is no additional hardware or software / abo needed. The required firmware on the inverter is on the inverter 1.34.6 or higher.
Yes, the max. State of charge on the inverter can be used to limit the charging, if e.g. a customer wants to do only charge it up to 80%. It is recommended to fully charge up the battery, to have the most energy available in case of a power outage.

With the activation of Battery control, the battery will be charged with at least 1,5kW, no matter where this energy comes from. This is set to ensure that the imported power is not too high and exceeds the load of the household-fuses on the switchboard. A feature to manually set the grid charging power is already planned.

If the PV-surplus exceeds 1,5kW, only the PV-surplus is used to charge the battery.  

The law states, that as soon as "grey" electricity is charged into a battery, the system loses the EEG tariff when it is priced out.

Exceptions:
The system is outside the EEG, e.g. takes part directly in the market or the discharge is confirmed via the storage guideline in accordance with VDE 2510-2.

What is required for the usage of Battery control:
An EnFluRi sensor (“Energieflussrichtung” sensor) that meets the requirements of the FNN guideline on electricity storage is required so that the battery can be charged from the grid. This ensures that the electricity fed in/stored is correctly allocated. Then charging the battery from the grid is also officially permitted for EEG remuneration. Fronius is working on a solution for this.

Our energy balance is a visualization that has been optimised to analyse what happens with PV production or the surplus and how the consumption is covered. Charging from the grid was deliberately excluded here at the time, as this was not relevant in a classic self-consumption-optimising system until now. The energy is counted as consumption, when it is discharged from the battery.

Fronius is working on a new view that makes this more transparent, clearly shows when a battery is being charged from the grid and is therefore more future-proof. As of now these flows can be monitored in the History chart in the Solar.web Portal using the ‘Energy from grid’ channel.