Webinar Series of DGE-ROLLOUT

Tuesday, 7 December 2021, 15:00 (CET/UTC+1), Jeroen van der Vaart, TU Darmstadt

As the world is looking for more reliable renewable energy sources, geothermal energy provides a scalable solution to any type of energy need. From heating to power generation, geothermal energy systems can provide a clean solution. The basis of geothermal energy is simple: Drill a few wells into the subsurface, pump water into it to let it be heated by the earth, and extract the heated water for our heating or, when hot enough, use it to generate electricity.
However, while the principle is simple, access to these resources is not always possible. The geological layers might not be in the best condition to drill, the heat needed might be too deep or when the resource is accessible, there might be no city or industry nearby that actually needs the resource. More importantly, drilling a well is not cheap so one needs to be sure about access to the heat.
The DGE-ROLLOUT project was launched to give a boost in starting to extract this energy. In this talk, the resource distributions and opportunities are discussed within the Northern Upper Rhine Graben. We will present the latest status in exploring deep geothermal energy in the Northern Upper Rhine and address questions like ‘What is needed for a successful geothermal project and what benefits can it deliver,’ ‘What are the risks and how do I lower them’ and ‘where do we start.’

Tuesday, 14 December 2021, 15:00 (CET/UTC+1), Timme van Melle, EBN

Tuesday, 11 January 2022, 15:00 (CET/UTC+1), Somil Miglani, VITO

As DH systems transition towards becoming climate-friendly, it is important that the share of renewable energy resources in heat production is maximized and the use of fossil fuels is limited. In most typical DH networks, fossil-fuel-based production units are used as backup systems, to cover peak heat load that cannot be covered by the baseload units due to capacity constraints. Their ability to ramp up and down fast makes them a good fit for this purpose. However, they cause high CO2 emissions and can be expensive to operate due to high fuel costs. To address this challenge, efficient and innovative heat demand management techniques that can manage the peak load is gaining attention.

Until now, demand-side management (DSM) in DH networks has been a complex problem to solve. However, with the availability of new technologies such as big data, artificial intelligence, advanced algorithms, IoT, and cloud computing, the solutions to the DSM problems are within reach. One such solution is an innovative technology called the STORM controller co-developed by VITO. This talk explains the potential for efficient and innovative DSM via the STORM controller for the Balmatt DH network located in Mol, Belgium. In this network, the base-load unit is a deep geothermal plant and the peak load is covered by a backup natural gas boiler.

In addition to DSM, other options such as an energy cascading system for efficient operation of the network are also addressed in this talk. In such systems, energy is transferred to several types of consumers according to their temperature needs resulting in optimal use of the total heat generated through reduced heat losses. Energy cascading also enables the connection of low-temperature energy sources to existing high-temperature networks helping in the transition towards renewable energy sources and reducing CO2 emissions.

Tuesday, 25 January 2022, 15:00 (CET/UTC+1), Claire Bossennec, TU Darmstadt

A heating district comprises several elements for which inputs and outputs fluctuate, depending on weather conditions and end-user consumption. The fluctuations lead, for example, to seasonally strongly varying utilization of combined heat and power (CHP) units, which produce electricity and capture heat thereby emitted. In winter, additional reheating by boilers usually takes place to cover peak loads. In summer, the output must be throttled due to the low demand for heat, reducing electricity generation and revenue.

The situation is similar with solar thermal collectors, a carbon-free heating option. While the generation potential is high in summer, the heat demand is low, whereas in winter, when the heat demand is high, the generation potential is low. Large-scale, seasonal heat storage is the only option to reduce heat generation potential and demand discrepancy. In this way, CHP units can continue to produce electricity efficiently under full load in summer, and solar thermal systems can also fully utilize the radiant heat potential of summer, replacing heat from conventional boilers.

Here, several geothermal storage options and experiences are presented, emphasizing medium-deep heat borehole heat exchangers, which require considerably less surface building space. This is of great advantage in urban areas, where heat consumption is concentrated. In addition, most of the heat is transferred to the deeper crystalline subsurface, which protects near-surface aquifers, compared to near-surface installations.

Tuesday, 8 February 2022, 15:00 (CET/UTC+1), Arianna Passamonti, Fraunhofer IEG

In order to achieve the European and German CO₂ reduction targets, of fundamental importance is the development of sustainable and renewable solutions for the heating sector, especially in the populated regions of North-West Europe (NWE) that largely rely on coal.

With this motivation, two projects were initiated: Geothermica HeatStore and NWE-Interreg DGE-Rollout. Within HeatStore, the development of a high-temperature mine thermal energy storage (HT-MTES) pilot plant is planned. During the summer, solar thermal energy will heat up the water present in a small flooded mine situated at the premises of Fraunhofer IEG, in Bochum. As part of DGE-Rollout, during the heating season, the mine water will be the heat source of a high-temperature heat pump (HTHP) that will be connected to the district heating (DH) grid.

Enterprises, SME, and national public authorities can profit from the project's experience offered in this talk for future investment decisions and regulations. In fact, on the one hand, the possibility to exploit flooded mine galleries as heat sources has a large potential in many regions of NWE in which underground mining was highly developed. On the other hand, it is possible to prove that environmentally friendly solutions such as heat pumps can be employed for elevated supply temperatures. This allows their exploitation starting from now for the energy transformation without the need for refurbishment of the entire district heating network.