Costs are only incurred if data points are requested. We offer a pay-per-use model, which shall ensure maximum transparency for the customer. A payment is required only for the amount of the requested data points. No data points mean no costs. The amount of data points can be viewed in Solar.web, where all amounts for the current and past months are listed. The amount for the current month is updated on a daily basis.

In addition, this model offers a high degree of flexibility when using the API. For example, you can carry out API queries cyclically(e.g. only on certain days of the week, at a certain time of day etc.) and depending on the query there is also the option of usingtime ranges and filters. That way, you can avoid querying values that are not required and thus minimize data traffic as well as the load on your server infrastructure.

If you do not actively use our API services (0 data points), no costs are incurred for that period of time. Therefore you will not receive any invoices. 

There are requests for PV system data and those for inverter data. The data points are summed up for all queries. Regarding thequeries for PV system data the number of inverters in the system is not relevant for determining the amount of data points. On theother hand when querying inverter data, PV system data points are not taken into account.

The data points of certain basic information about your PV systems, such as the number of systems and components, are not counted. The frequency of such queries is irrelevant.

Detailed information about the PV system, real-time data (power flows) and the current weather data are counted as one data point per response. The frequency of the queries can be freely chosen depending on the application purpose (e.g. every 30seconds for real-time data, once per hour for current weather data, etc.)

Historical and aggregated energy data (e.g. production and consumption, as well as forecast data) and service messages are counted as data points per value and per timestamp. A single value such as energy fed into the grid per month would be counted as 12 data points for the period of the last 12 months. If total consumption and self-consumption were queried for a period of 10hours (considering the default time logging interval of 5 minutes set on the inverter) the number of data points can be calculated as follows:

60 minutes / 5 minutes log interval = 12 data points per hour.

Multiplying these 12 data points by the query period of 10 hours results in 120 data points per queried value. Since we are querying two values in our example the final sum of the data points would be 240.

Below are some sample calculations for various applications.

 

Data query for a PV system with a Smart Meter

Power flow data is queried at the PV system level (not at the inverter level). The data is requested every 60 seconds for 24 hours per day.

The amount of data points per month is calculated as follows:

60 queries/hour x 24 hours x 30 days = 43,200 data points per month

 

Data query for a PV system with a Smart Meter

Aggregated energy data for the three API channels gridfeedin, gridpower and selfconsumption is queried. The data is requested hourly, 24 hours per day for daily, monthly, annual and total values.

The amount of data points per month is calculated as follows:

1 query/hour x 4 time intervals x 3 channels x 24 hours x 30 days = 8,640 data points per month

 

Data query for a PV system with a Smart Meter

Historical energy data is queried for the three API channels gridfeedin, gridpower and selfconsumption. The data is requested every 5 minutes (corresponds to the standard setting of Fronius inverters), 24 hours per day

The amount of data points per month is calculated as follows:

12 queries/hour x 3 channels x 24 hours x 30 days = 25,920 data points per month

 

Data query for a PV system with 10 inverters

Historical data is requested for one API channel (produced energy) is queried. 

The query provides the data at 5-minute intervals for 14 hours a day (usual operating time of the inverter). 

The amount of data points per month is calculated as follows:

12 queries/hour x 10 inverters x 1 channel x 14 hours x 30 days = 50,400 data points per month

 

Data query for a PV system with smart meter and storage system for a monitoring solution

Since a combination of several different data queries is common in practice, the data query for the provision of a photovoltaic visualization application for end customers is shown in this application example.

Power flow data is queried at the PV system level. The data is requested every 15 seconds for 30 minutes a day.

The amount of data points per month is calculated as follows:

240 queries / hour x 0.5 hours x 30 days = 3,600 data points per month

In addition, historical data are requested every 5 minutes for 24 hours.

The amount of data points per month is calculated as follows:

12 queries / hour x 5 channels x 24 hours x 30 days = 43,200 data points per month

Furthermore, aggregated energy data for the 5 API channels grid feed-in, grid power, battery charging, battery discharging and self-consumption are queried. The query takes place once a day for the daily, monthly, annual and total values. 

The amount of data points per month is calculated as follows:

1 query / day x 4 time intervals x 5 channels x 30 days = 600 data points per month

For this use case, the result is a total of 47,400 data points per month. The data points calculated in the application examples can be multiplied depending on the number of PV systems. The calculationof the data points is always linear.

There is a difference regarding 0 and NULL values. 0 means that there is a measured value but it is really 0 (e.g. produced power during night equals 0). NULL means that data for this value is not available. This case often occurs when a PV system is not connected to the Internet. NULL data points are not counted and are therefore not part of billed amount.

A query does not automatically correspond to one data point, but can also be consist of several data points. This depends on the type of query and the number of channels or metadata queried.

To access the data of a Fronius PV system via the API, the owner's consent is required. Depending on the use case, Fronius offers two ways of obtaining this consent and then integrating the data into your application:

• You have access to PV systems in your Solar.web account (guest rights are sufficient to view most data). However, if you want to view service notifications for specific PV plants, you need the authorization as a plant maintainer. Please note that permission to access system data must always be clarified directly with the owner or proprietor of a PV system and is outside Fronius' area of competence.
• User Impersonation: For some applications it makes sense to view PV systems in the context of another user. For these cases, the Solar.web Query API offers the possibility to perform an impersonation using JSON Web Token (JWT). Access to Solar.web Premium functions is only possible if a valid Solar.web Premium membership is available for the Solar.web user account containing the PV plant. 

Detailed information on implementation, as well as practical application examples, can be found in the interface documentation.