Nuuka open API, which provides energy consumption information for the City of Helsinki’s service properties, is a channel through which the user can search for information about properties owned by the City of Helsinki and their energy consumption. The interface is completely open and does not require authentication.
The APIs are divided into property data search and energy data search. Searches can be made based on the feature’s name, purpose of use and property number.
The properties can be listed, and you can search for more detailed information about them. Note the difference between properties and buildings: one property can include several buildings, such as a school and a daycare centre. When searching for property data, the data of the buildings contained in the property are also returned. The coordinate system used is WGS84 Web MERCATOR (EPSG:3857).
Energy data can be searched for at the monthly, daily and hourly level. The availability and accuracy of the data varies according to the feature. The oldest data is at the annual level, starting from around 1980. The most accurate, hourly data is generally available from 2015. There are four possible reporting groups: electricity, heating, water and cooling. All energy data is displayed at the property’s main meter level. Monthly data can also be retrieved as normalised. The data is updated once a day.
More detailed information about the various interfaces can be found in the Swagger documentation. The data is returned in JSON format.
There are deficiencies in the database data. Gaps in the time series can occur at all levels and over the entire covered period. The accuracy of data validation depends on the energy type and the source of the data, which in turn depends on the time and destination. In principle, the more recent the data is, the more exact it is. The most recent data is also monitored and corrected when errors occur.
Example searches:
- List all properties: https://helsinki-openapi.nuuka.cloud/api/v1.0/Property/List?Customer=Helsinki
- Search daily energy consumption (ReportingGroup=Electricity) for the property Hakaniemi Market Hall (PropertyName=1000 Hakaniemen Kauppahalli) for 2019: https://helsinki-openapi.nuuka.cloud/api/v1.0/EnergyData/Daily/ListByProperty?Customer=Helsinki&Record=LocationName&SearchString=1000%20Hakaniemen%20kauppahalli&ReportingGroup=Electricity&StartTime=2019-01-01&EndTime=2019-12-31