Thermal de-icing and snow melting approaches to control of winter conditions on infrastructure surfaces offer a number of advantages compared to conventional techniques. These include the automated control of safe surface conditions, avoidance of chemicals and their environmental impact and prolongation of the life of the infrastructure. Hydronic systems can take advantage of collection of solar energy in summer conditions and seasonal storage of thermal energy by geothermal heat exchange. Making use of these renewable resources and energy storage enables savings in primary energy.
Shallow geothermal energy, as a classic storage technology, offers great potential for the substitution of conventional energy and can also contribute to relieving the power grids in winter, as snow melting and de-icing systems can’t simply be switched off, since they are always used in critical sections of infrastructure. In some cases the cooling of pavements during summer will decrease the wear on the surface as well as on tires.
In principle, all existing hydraulically operated systems can be relatively easily converted to ground-coupled heat pumps. In the case of new plants, direct-electrical systems can and must also be replaced, since these are no longer compatible with the upcoming challenges of the energy transition in the medium term (grid load).
The overall goal of this Annex is to contribute to the replacement of electrical resistance heater systems and expanding utilization of direct geothermal heating systems or ground source heat pumps in de-icing and snow melting of infrastructure.
To achieve the goal of this Annex the existing knowledge of the experts working in this area will be summarized and further developed by the planned research activities in the subtasks. According to that, a potential study is to be carried out in each of the participating countries, in which the market volume of as many relevant applications as possible is to be determined. In addition, an overview of the state of the art of these systems for different applications in various climate will be worked out.
Some geothermal systems for de-icing and snow melting have already been built in Japan, USA, Canada, Switzerland, Sweden, the Netherlands and Germany, either as pilots or, in some cases, as full-scale systems. These systems will be documented as uniformly as possible and, wherever possible, will be accompanied by monitoring. Within the framework of the accompanying research projects, further demonstration plants will be built, which will also be monitored. In addition to demonstrating the full functionality of the technology, valuable experience will be gained from existing facilities (function, performance, energy consumption, investment and operating costs, …).
From the experience gained from the construction and operation of the demonstration plants in various climatic conditions, as well as from the experience of existing plants, recommendations are to be drawn up which summarize the essential aspects regarding the planning, construction, operation and maintenance of geothermal snow melting and de-icing systems. These recommendations will then be the input to national guideline committees, e.g. VDI 4640 in Germany.
With the summarized knowledge gained from the experts of surface heating systems, snow melting and de-icing systems will be developed for specific applications which are adapted for efficient geothermal heating. The development will include design programs and simulation tools for calculations of thermal loads.
An important aspect to bring these systems more into the market is to work out the benefits for the environment, social as well as the economic benefits. This will be handled in a separate work package for the different applications of the technology.
Finally, the results of the Annex will be used to develop recommendations for further market and technology development.