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Project description

Geothermal Community Heat technology and Transfer (GeoCoHorT)

Summary

GeoCoHorT aims to accelerate the transition to 4th generation district heating and cooling (4GDHC) in Europe and globally, by assessing, optimizing, and demonstrating the integration of shallow geothermal heat extraction with other renewable sources and smart buildings. The main case study is a micro-district in Limerick, Ireland, comprising commercial and residential buildings. One of the target geo-sources is ground water from the River Shannon, which will provide both an efficiency and noise-reduction benefit to the micro-district and a method of combatting climate-change-warming of the Shannon Estuary. The project investigates how the heat from this and other low-temperature sources can be recycled and supplied to the smart district through heat pumps powered by intermittent renewable electricity and by means of a suitable DH network design. The mandate is to find solutions that work for entire communities in a fair and sustainable manner, with the involvement of the communities themselves to highlight their needs.

The long-term aim is to assess non-conventional and low-temperature sources for heating and cooling and their integration into small and medium scale DH networks and smart buildings. The project will deliver a user-friendly resource/demand matching tool, which community members and city planners can use to understand the cost/benefit of employing locally available (geothermal or other) resources for heating a district in that community. The tool will provide optimized DH system configuration, costs, and environmental impact and will assist in decision-making. The benefits that a successful

GeoCoHorT will bring to the society are:

  1. reduced dependence on fossil fuels for heating and cooling;
  2. reduced CO2 emissions;
  3. increased exploitation of intermittent renewable energy sources;
  4. cooling of water sources/reservoirs such as rivers and lakes and mitigation of global warming effects;
  5. simple and community-oriented planning for investing in local DH systems.

Technical Descriptions

The project aims to develop an innovative tool for optimizing the integration of shallow and deep geothermal energy sources, including ground loops, water loops (rivers, canals), and combinations thereof, into 4th generation district heating and cooling (4GDH) networks. The tool will consider various configurations, energy storage options, and variable renewable energy sources to identify optimal solutions for minimizing fossil fuel dependence, reducing CO2 emissions, and enabling environmental benefits through targeted temperature management.

State of the Art

Existing tools like NREL's REopt and NETL's FRACGEN/NFLOW models provide techno-economic optimization and simulation capabilities for renewable energy systems and geothermal reservoirs, respectively. However, these tools have limitations in considering the breadth of geothermal sources and configurations relevant to 4GDH networks. The proposed project aims to innovate by incorporating a wider range of geothermal options, including ground loops (horizontal and vertical, shallow and deep), water loops (free-stream and under-bed), and their combinations, while also considering temperature-based environmental impacts.

Research Questions:

  1. How can heat be extracted from river estuaries or other water bodies for district heating and cooling purposes in a sustainable, cost-effective, and environmentally friendly manner?
  2. What are the potential environmental benefits of targeted temperature management through geothermal energy extraction or rejection?
  3. What are the challenges and market factors associated with coupling shallow geothermal systems with 4GDH networks in the presence of variable renewable electricity sources?
  4. How can prosumers be effectively integrated into micro-district heating networks supplied by geothermal energy?
  5. How can the proposed solution benefit citizens and city planners in terms of community involvement, energy resilience, and sustainable urban development?

Research Objectives:

  • Locate riverine heat exchange surfaces to maximize the possibility of cooling estuarine water.
  • Identifying the best way to employ geo-resources for integration with DH to obtain the most energy gain. Demonstrate a vertical closed loop or open loop.
  • Produce a user-friendly resource/demand matching tool that which the community members can use to understand the cost/benefit of employing locally available geothermal resources for heating a district in that community.
  • Optimize 4GDH architecture with the aid of physics-based and data-driven models for small and medium-scale networks integrated with secondary and non-conventional sources (including, but not limited to, heat pumps, house boilers, solar systems, energy storage, etc.)
  • Optimize system behaviour by integrating secondary and non-conventional heating flows into the overall functionality of smart buildings (prosumers).
  • Improve the air-source heat pump (ASHP) design at the Chisel and Oak complex and assess the capabilities and efficiency for micro-DH system. Evaluate the conversion on the ASHP micro district to river-sources heat pump district
  • Propose an attractive business model for small- and medium-scale 4GDHth4th generation DH in small and medium scale towards smart and sustainable urban development for various EU and USA scenarios.

Expected Results:

  • River estuary cooling considered as non-conventional heat source for 4GDH, providing increased heat-pumping efficiency and potential to reverse negative impacts of atmospheric CO2 concentration.
  • Heat-electricity sectors coupling through thermal storage and geo-sourced heat pumps, enabling excess wind energy utilization for heat pumps and thermal storage, supporting renewable integration while reducing fossil fuel demand.
  • Working model of small-scale 4GDH with prediction capabilities, flexibility for different communities and heat sources. Simulating DH loops, thermal storage, distributed sources, analyzing performance, smart control, storage requirements, and sustainability.
  • Heat extraction model from river groundwater, hyporheic flows and free stream. Comparing likelihood of cooled water improving estuary temperatures. NETL geo-loop models as input to larger 4GDH model.
  • User-friendly resource/demand matching tool for the community to understand cost/benefit of employing local geothermal resources for heating. Matching geothermal sources with district-heating designs, reporting costs, power requirements. Serving as template for worldwide application, including other renewables.
  • Community awareness and social involvement for proposing new local energy management system without infrastructure destruction. Providing science and stakeholder acceptability basis for fair and transparent process aligned with UN SDGs. Potential link to Ballyhourra sustainable energy community.

Methodology:

  • Develop model for the geothermal source and calculate potential heat extraction (NETL, WP3).
  • Develop model for the DH loop and include prosumers (MDU, WP3).
  • Integrate the models so that temperature, flow, and thermal power from the geothermal heat source are used as input in the DH loop, together with other user-defined distributed sources (NETL, WP3).
  • Test the models with data collected in the pilot site in Limerick (MDU and UCC, WP3-WP4) and demonstrate the DH loop on the pilot site (MEGA, WP5).
  • Produce a business model first for Limerick and then extended to the whole of Ireland (UCC, WP4-WP5).
  • Develop a user-friendly matching tool that can test several DH network configurations with user-defined inputs and provide guidelines about optimal alternatives based on energy consumption, costs, installation/retrofit cost, and emissions; Limerick's community will be the case study (NETL and MDU, WP3).
  • Raise awareness in the community through educational and promotional activities, where questions, methods, and results from the project will be disseminated; the goal is to increase acceptance and citizens involvement to ensure future exploitation (MEGA, WP2).
  • Define exploitation strategies by producing business models for relevant EU and US areas/markets and leveraging Swedish long-term experience with DH; a road-map to marketability in 2030 will be defined (MEGA and all, WP6).