Diverse DH Pöchlarn - Diversifi­cation strate­gies for a sector-coupled district heating supply in the mu­ni­ci­pality of Pöchlarn

Starting point / motivation

The small town of Pöchlarn has developed an integrated, holistic modular climate protection concept (The Green Line - Smart City Pöchlarn 2030). The aim is to reduce dependence on individual energy sources, particularly in the heating sector (e.g. biomass in district heating or process natural gas), but also to utilize the existing potential in the electricity sector (e.g. surplus PV electricity).

The demand for the existing district heating network is currently provided by a biomass boiler plant, waste heat from an existing biogas CHP plant, industrial waste heat and sometimes even heating oil. In addition, there are a large number of energy assets in the municipality or they are currently being built and do not work together as part of an overarching strategy, especially as this means there are many degrees of freedom and the level of complexity is very high.

Existing:

• PV system (4.1 MWp)
• biogas plant (500 kW_el)
• biomass plant (5 MW_th)
• industrial waste heat (1 MW_th)
• rapid e-charging station (350 kW_el)

Planned:

• 2 large heat pumps (700 kW_th each) to relieve the biomass heating plant and to increase the storage density of the long-term heat storage facility
• solar thermal collector field (6,000 m2)
• photovoltaic-thermal solar collectors (PVT; 2,000 m2)
• a long-term heat storage facility (8,000 m³)
• large electrical storage facility (10 MWh)
• 6 x wind generators (90 kW_el)
• further waste heat extraction (1 MW_th)

As can be seen, the municipality of Pöchlarn offers ideal conditions for a scalable sector-coupled district heating supply that can be transferred to other cities, while at the same time diversifying energy sources and increasing resilience and securing the industrial location.

However, an overarching strategy (land use/dedication, technoeconomically optimized operating model of the overall energy system, handling of data exchange/data protection/ operator structure for optimal regulation) is still lacking for implementation, while at the same time urban heat planning must take this into account.

Contents and goals

The aim is to research diversification strategies for a sector-coupled district heating supply in the town of Pöchlarn, taking into account the town's objectives, existing energy assets and energy sources. Urban heat planning should also be geared towards this. Research is to be carried out into how an upstream energy center can take over the price-signal-controlled and grid-supportive regulation of the overall system via the downstream assets:

• Energy generation systems (large photovoltaic system, solar thermal energy, biomass and a large heat pump (RWP))
• Charging management for the long-term heat storage system
• E-mobility supercharger systems
• Large-scale electricity storage

In terms of increasing resilience, there are various conflicting objectives that need to be resolved at the same time.

Expected results

1. strategy of sector-coupled diversification of the district heating supply
2. 100% substitution of biomass and the fossil share of currently around 7,437 MWh/year
3. recommendations for new urban system concepts for secure, market-independent energy generation
4. price security for the future
5. solutions for resolving the conflicting objectives
6. publication and dissemination to the relevant target groups
7. GHG savings of approx. 1,880 tons/year

Project management

4ward Energy Research Ltd.

Project or cooperation partners

Dr. Christof Bernsteiner
Reininghausstrasse 13A
A-8020 Graz

Tel.: +43 (664) 10 777 63
E-mail: christof.bernsteiner@4wardenergy.at
Web: www.4wardenergy.at