New Online Service Promotes Sustainable and Fair Use of Geothermal Energy in Helsinki
The popularity of ground heat has grown steadily in Helsinki over the years, driven by demand for energy-efficient and emission-free heating solutions. As the number of geothermal heating systems increases, concerns have emerged about the effects of borehole fields on the geothermal resources of neighboring properties. In response, the Geological Survey of Finland GTK and the City of Helsinki Urban Environment Division have jointly developed an innovative online service to help designers and companies to assess the thermal effect of borehole fields.
In a densely built urban environment, the growing number of borehole fields can lead to a situation where properties consume geothermal resources from neighboring plots. To address this, the city of Helsinki has updated its geothermal heating guide for designers to ensure equal access to geothermal energy for all landowners.
According to the new guidelines, energy sufficiency for neighboring properties must be demonstrated through energy calculation if a plan involves at least 10 boreholes or the borehole is deeper than 1,000 meters. However, producing such calculations is often challenging, as it requires specialized expertise and suitable software.
To meet this need, GTK has developed eVala, an online service for calculating the thermal effect of borehole fields. Available free of charge on GTK’s website, eVala enables users to generate an energy calculation document suitable for inclusion in a building permit application to the city.
“eVala is primarily intended for geothermal system designers, but it also serves other professionals in the geothermal energy sector. The service enables uniform energy calculations, simplifying the building permit process and eliminating the need for separate heat transfer modeling,” says Project Manager Kimmo Korhonen from GTK.
Is there enough geothermal energy for everyone?
Geothermal energy is a renewable resource, but excessive heat extraction from the ground over time can locally deplete it.
Depending on plot size, the number of boreholes, thermal load, and proximity to neighboring plots, a landowner may end up consuming geothermal resources beyond their own property. The regeneration of geothermal energy takes time—typically as long as it took to deplete the resource.
eVala is not designed for planning borehole fields but rather for assessing the thermal effect of an existing plan. Users input data on the boreholes and the heating and cooling loads. The output is a PDF report estimating the distance over which a temperature drop of 1, 2, and 3 degrees Celsius extends after 25 and 50 years of operation. According to the city of Helsinki guidelines, a two-degree temperature drop at the property boundary is permissible.
A first in Finland
eVala is the first online service developed in collaboration with a city to provide all stakeholders with an equal opportunity to evaluate the sustainability of their property’s geothermal energy solution. It offers planners, industry professionals, and the city a standardized, efficient, and comparable method for assessing the impact of borehole fields on neighboring geothermal resources.
The software was also designed with adaptability in mind, making it suitable for use by other cities and regions.
“As a digital solution, eVala’s architecture can be tailored to similar needs elsewhere. In collaboration with our partner Solita, we created a comprehensive solution that supports planning and decision-making in urban environments,” says Pyry Lehtonen, Team Manager at GTK.
The collaboration between GTK and the city of Helsinki on eVala exemplifies how data-driven planning can simultaneously promote equity, service efficiency, and climate goals in urban development. The tool also provides geothermal sector companies with a means to ensure the viability of their projects and meet city requirements effectively.
Further information
Kimmo Korhonen, Project Manager
Geological Survey of Finland GTK
kimmo.korhonen@gtk.fi
tel. +358 29 503 2202
Pyry Lehtonen, Team Manager
Geological Survey of Finland GTK
pyry.lehtonen@gtk.fi
tel. +358 50 348 6639
Online service eVala for the assessment of the thermal effect of borehole fields in Helsinki, Finland (service available in Finnish only):
Go to eVala online service on GTK`s website
The City of Helsinki geothermal heating guide for designers:
Go to the City of Helsinki website
