Energy transition with biomass residues and waste: regional-scale potential and conflicts. A case study from North Hesse, Germany

ABSTRACT

Bioenergy plays a significant role in the expansion of sustainable energy transitions based on renewable energies, and thus in achieving climate targets through decarbonization of global production and consumption patterns. This article deals with the question of whether and which bioenergy potentials exist and the barriers and preconditions relevant for utilization from a regional perspective based on stakeholder interviews in North Hesse, Germany. Insights were gained into the objectives that regional stakeholders associate with energy recovery from residual and waste materials and the role of ecological modernization in this context. Under current conditions, regional stakeholders assess the potential of biomass residues for energy use as low owing to legal barriers to the use of biomass residues and waste for energy, a high degree of fragmentation, and locally specific design of the uses of these resources. These regional stakeholder assessments contradict the expansion targets and potential calculations of government agencies and research centers. Furthermore, regional stakeholders do not link the expansion of residue- and waste-based bioenergy with ecological modernization objectives (i.e. linking ecological objectives with increases in innovation, growth, and employment), but are mainly driven by the search for cost-savings, improved efficiency, and more sustainable use of biomass residues.

KEYWORDS:

• bioenergy
• energy transition
• energy conflicts
• ecological modernization

Introduction

Bioenergy is of central importance in the context of sustainable energy system transition processes in order to achieve climate goals by decarbonizing global production and consumption patterns (Gawel et al., 2019). Compared with other renewable energy sources, biomass has the advantage that it can directly replace fossil fuels and can be stored as needed for the generation of heat, electricity, and fuels. In the last decade, the use of biomass for energy has increased massively worldwide, including in many European regions (e.g. by the German agency for renewable energy– AEE Agentur für Erneuerbare Energie, 2018; Strzalka et al., 2017). The International Energy Agency (IEA) projects that bioenergy will provide 17% of the global final energy demand by 2060 (compared with 4.5% in 2015), by saving up to 20% of greenhouse gas emissions (OECD / IEA, 2017, p. 7). According to the European Bioenergy Network, biomass accounts for about 10% of total European energy consumption (AEBIOM, 2017). With regard to the European energy system, biomass will continue to play an important role in the future despite its limited availability, especially when it comes to balancing fluctuating electricity volumes from wind and solar energy (Strzalka et al., 2017). In the German context, the simultaneity of climate protection targets and the nuclear and coal phase-out in Germany has further increased the pressure to switch to renewable energies and thus also to bioenergy. Nevertheless, there is still no satisfactory answer as to whether the existing biomass potentials are sufficient to meet the diverse and increasing demands for both material and energy uses. The extent to which bioenergy can play a key role in future energy systems will also depend on how competition for renewable resources develops in the context of bioeconomy strategies (Lago et al., 2019). Furthermore, the use of biomass for energy generation is controversial for a number of reasons, especially regarding the cultivation of energy crops. Three aspects in particular are problematic: firstly, the use of cultivated biomass as an energy source per se (food vs. fuel debates; Pehlken et al., 2016; Schumacher & Schultmann, 2017); second, the comparatively high land requirements of bioenergy compared with wind and solar energy generation (ecological inefficiency); and third, the cultivation of energy crops as large-scale monocultures which is also criticized by environmental protection organizations (e.g. BUND – Bund für Umwelt und Naturschutz Deutschland) and the German Federal Environmental Agency (UBA – Umweltbundesamt) for its negative impacts on biodiversity, high pesticide use, etc. (BUND, 2010; UBA, 2012).

Compared with the cultivation of energy crops, the use of biomass residues and waste for bioenergy generation is considered a more sustainable approach in biomass research (Pfeiffer & Thrän, 2018), especially when combined with decentralized, regional, or local use of these resources for both energy use and heat generation (Hauser & Wern, 2016). The issue of heat supply is highly relevant here, as heat supply accounts for a significant share of carbon dioxide emissions. In Germany, heat accounts for half of the final energy consumption, but only 13.9% of heat is currently supplied by renewable energy sources (Steubing et al., 2020), At the European level, heating (and cooling) has so far been based primarily on non-renewable energy, which also requires a rapid heat (and cooling) transition in view of the Paris climate targets (Steubing et al., 2020). At the technical level, the conditions for expanded generation and use of bioenergy are promising: ‘Modern bioenergy is obtained by mature technologies currently available in the biomethane market from wastes and residues, district heating networks, agricultural residues to generate electricity […]’ (Lago et al., 2019, p. 5).

The central questions now are whether and which biomass potentials are available for an extended use and under which conditions as well as which forms of sustainable uses are promising. The research results presented here attempt to answer these questions from a regional perspective based on research in the region of North Hesse, Germany. In this paper, the results of an interview study with regional stakeholders on bioenergy potentials are presented. The aim of the research was first to determine whether or which regional bioenergy potentials exist and how their current and future utilization (or non-utilization) is assessed from the perspective of regional stakeholders. Second, the framework conditions for utilization strategies (i.e. in the sense of sustainability, in particular ecologically compatible, decentralized, and efficient utilization paths such as bioenergy-based local heating) were evaluated. This study was conducted in the context of research into decentralized energy transition in Germany (‘Energiewende’), which has attracted strong international attention at the political and scientific levels; for a detailed overview see Beveridge and Kern (2013), Gailing and Moss (2016). In the study region of North Hesse, Germany, there have been approaches for municipal energy transition for 30 years, which have emerged from niche existence and have now found (supra-)regional dissemination (Bauriedl, 2016). However, previous attempts in this region have focused on energy transition processes associated mainly with wind- and photovoltaic-based energy generation (Baasch, 2016; Bauriedl, 2016). The focus of this research project was on the renewable heat transition.

The article is structured as follows. First, ecological modernization strategies are discussed regarding their role as important drivers for both bioeconomy and bioenergy strategies. Subsequently, the state of research on the role of bioenergy in the context of the German energy system transition and possible areas of conflict in the expansion of bioenergy are outlined. Subsequently, previous findings on governance innovations and actor landscapes of both the German and North Hesse’s energy transitions are presented. In the empirical section, the research design and questions are presented, and then the results of interviews are outlined and discussed. The results show that regional stakeholders assess the potential of biomass residues for energy use under current conditions as low. The main reasons cited for this are legal barriers to the use of biomass residues and waste for energy, a high degree of fragmentation, and locally specific design of the uses of these resources. These regional stakeholder assessments contradict the expansion targets and potential calculations of government agencies and research centers. Furthermore, the results show that regional stakeholders do not link the expansion of residue- and waste-based bioenergy with objectives of ecological modernization (i.e. linking ecological objectives with the increase of innovation, growth, and employment), but are mainly driven by the search for cost-savings, improved efficiency, and more sustainable use of biomass residues.

Ecological modernization strategies as a driver for bioenergy

Bioenergy policy, both as part of a broad bioeconomy-oriented policy and renewable energy transition, is strongly related to high expectations regarding goals such as climate protection through greenhouse gas mitigation, energy security, and rural development (Gawel et al., 2019). The strategies for achieving these goals are based on technological, organizational, and institutional improvements following the ideas of ecological modernization strategies focusing on environmental reforms in specific social practices and institutions, such as the institutional and structural anchoring of climate and environmental policy goals as an indicator of development towards a sustainable society. Since the origins of the concept of ecological modernization in the 1980s, different theoretical and conceptual understandings have been developed (see Brand, 2014; Hajer, 1995; Mol et al., 2014; York et al., 2010).

Ecological Modernization is rooted in the assumption that development towards sustainability is (only) possible within existing structures, whereby political, economic, and societal actors and institutions are assumed to have the will and ability to change and adapt (Mol et al., 2010, 2014). Here, ecology and economy are combined in an advantageous way: environmental productivity, that is, productive use of natural resources and environmental media (air, water, soil, ecosystems), can be a source of future (green) growth and development. This includes increases in energy and resource efficiency as well as product and process innovations such as environmental management and sustainable supply chain management (Krüger, 2016). Urgently needed reforms for a sustainable future can be imagined within a wide range of possible futures: from insisting on the feasibility of unlimited growth to including its capitalistic or industrial character as well as the complex, highly administrated technological system of modern society (Murphy & Gouldson, 2000). Politics plays an important role here by creating reliable and calculable conditions through participatory governance processes, including the involvement of civil society actors, granting economic incentives (innovation-friendly regulation), or by sanctioning non-environmentally friendly (production) practices (Jänicke, 2008).

Ecological modernization has been widely discussed from various perspectives (e.g. Bäckstrand & Lövbrand, 2007; Brand, 2010; Brand & Wissen, 2014; Mol et al., 2014; York et al., 2010). The main points of criticism are doubts about the fundamental attainability of sustainability goals within capitalist economic structures (Brand, 2010; Brand & Wissen, 2014), insufficient consideration of economic and social inequality (York et al., 2010), and the increasing consumption of fossil energy resources such as coal, which counteracts sustainable development (York et al., 2010). Critical evaluations of ecological modernization theories also examine the origins and influences of new market-based forms of carbon governance; for example, Bäckstrand and Lövbrand (2007, p. 127) state that the ‘predominance of the ecological modernization discourse and its market-based, flexible and cost-effective greenhouse gas mitigation approach’ has led to an international win-win compromise that has ‘effectively silenced’ more radical demands for distributive justice and per capita allocations. Within the ecological modernization narrative, to realize growth without further environmental destruction, alternative mitigation strategies, institutional and structural transformations related to sufficiency, degrowth, or energy sovereignty seem to be needless struggles. Bailey et al., 2011, p. 682) suggested to ‘explore the governance dimensions of these novel market mechanisms, look at how they work, and then discuss whether, to what extent and for whom they work‘ for a better understanding of the processes through which the seemingly intractable problem of climate change has been framed as an opportunity to construct a new carbon economy.

The German energy transition is strongly linked to the ideas of ecological modernization (Hillebrand, 2013; Jänicke, 2008; Quitzow & Thielges, 2020). Here, an economically sensible ‘greening’ of the energy system is set as a framework for coping with climate problems (Hillebrand, 2013, p. 678). Furthermore, the energy transition is not only seen as a response to environmental challenges, such as the risks of nuclear energy and climate change, but also as a driver of innovation, growth, and employment with important export opportunities for German companies (Quitzow & Thielges, 2020, p. 8). In the following, the current state of knowledge on the role of bioenergy in the context of the German energy system transition and the central bioenergy conflicts are briefly outlined.

Bioenergy as a strategy of German energy transition

The energy transition in Germany today is based mainly on decentrally generated resources. According to the think tank Agora Energiewende, in 2018, renewables accounted for 35.3% of Germanýs gross electricity generation; of this onshore wind accounted for 14.5%, followed by 8% for biomass, 7.1 for photovoltaic (PV), 3% for offshore wind, and 2.6% for water (Agora Energiewende, 2019). Nearly a quarter of renewable energy generation is based on biomass, while heat generation from renewable energies in final energy consumption for heating and cooling is almost 90% biomass-based (AEE, 2018). The expansion of renewable energy sources, including bioenergy, has been extremely dynamic. In the last 20 years, the share of biomass-based energy and heat generation has increased significantly: in 2000, the share of bioenergy in gross electricity generation was just 0.8% (8.5% in 2017) and in the heating sector was just 4.1% (11.5% in 2017; AEE, 2018). The increase in new installations for biomass-based electricity during the last almost two decades is attributed mainly to feed-in tariff laws under Germanýs renewable energy act (EEG – Erneuerbare Energien Gesetz) since the year 2000 (Hauser & Wern, 2016). The introduction of a new flexibility bonus in the EEG in 2012 remunerated additional capacity installation and provided more flexible modes of operation, leading to the installation of new additional capacity for more flexible operation modes (Hauser & Wern, 2016). By the reform of the feed-in tariff laws in 2014, the incentives for further development of biogas were significantly reduced. The future development of biogas plants in Germany is uncertain: after the end of 20-years of guaranteed EEG remuneration, many biogas plants will not be able to continue operation under market incentives alone beyond their funding period (Purkus et al., 2018). The tightening of the EEG in 2014 also had a negative impact on governance innovations as it aggravated the formal conditions for renewable wind, solar, and biomass plants, thereby hindering energy cooperatives from constructing new renewable facilities (Klagge & Meister, 2018).

Nevertheless, according to calculations by the Agency for Renewable Resources (FNR – Fachagentur für Nachwachsende Rohstoffe), the energetic biomass potential could be further expanded in the future. In 2050, 26% of the national demand for heat, energy, and fuel could be satisfied with national biomass from agriculture, forestry, and waste (FNR, 2017). To achieve these expansion targets, a reference is made to calculations according to which two-thirds of the agricultural and one-third of the forest biomass potential remain unused. In addition, more efficient use of biomass in energy and heat generation is required (FNR, 2017).

Bioenergy conflicts in Germany

The bioenergy discourse in Germany is influenced by governmental actors at the federal and state levels (especially the Federal Ministry of Food and Agriculture [BMEL – Bundesministerium für Ernährung und Landwirtschaft] the Federal Ministry for Economic Affairs and Energy [BMWi – Bundesministerium für Wirtschaft und Energie], and the Federal Ministry for Research and Education, Federal Environmental Agency [BMBF – Bundesministerium für Bildung und Forschung]), scientific actors from the field of technical and environmental research (especially DBFZ – Deutsches Biomasseforschungszentrum / German Biomass Research Center), social sciences (human geography, political science, sociology, etc.), interest groups and networks of the renewable energy industry (e.g. AEE), renewable energy think tanks (Agora Energiewende), and nature and environmental protection associations (e.g. BUND). The use of biomass for energy generation has long been controversial, especially with regard to ethically based food versus fuel debates focusing on energy crops (Pehlken et al., 2016; Schumacher & Schultmann, 2017). The potential role of biomass in Germanýs energy transition is controversial: on the one hand, environmental NGOs and Germanýs Environmental Agency criticize the use of biomass for energy generation in general for being the most land consuming renewable energy source and therefore inefficient compared with wind and solar, with the exception of using biomass waste under certain conditions (BUND, 2010; UBA, 2012). On the other hand, proponents of biomass-based energy generation such as Germanýs Agricultural Ministry point out the advantages of biomass, such as multifunctional usability for energy, heat, and fuel generation, compared with wind and solar (BMEL, 2014).

On a national scale, the high technical potential of bioenergy contributing to the flexibility of the power system is used as an argument for keeping bioenergy in the technology mix, at least until other climate-friendly and cost-effective flexibility options have been developed (Purkus et al., 2018). Biomass energy also offers a variety of cheap and technically easy storage options (BMEL, 2014) and is therefore the most reliable, least fluctuating renewable energy source (Purkus et al., 2018). In addition, proponents point out that Germany’s population is predicted to decline; therefore, less agricultural areas for food and feed generation or settlements will be needed in the future, which opens new areas for energy plant cultivation (AEE, 2018). Another argument focuses on the cultivation practices of energy plants. Proponents argue that optimized energy plant cultivation in Germany could contribute simultaneously to higher biodiversity and higher harvest yields. Therefore, a change in current farming practices is necessary. Today, farmers often focus only on a limited spectrum of energy plants, especially maize monocultures, owing to a lack of knowledge and a short-term focus on the most profitable harvest. Longer term benefits and more sustainable approaches include varying crop rotation and considering a wider spectrum of energy plants, which could ideally avoid monocultures and soil degradation (AEE, 2018).

While the cultivation of energy plants remains controversial, a less disputed option from the perspective of biomass research is an increasing and more efficient use of biomass waste and residues with lower environmental impacts than those associated with biomass cultivation (Pfeiffer & Thrän, 2018). Studies suggest that residual and waste materials represent a large part of the previously untapped expansion potential. However, further development of efficient utilization methods is needed to exploit this potential (Pfeiffer & Thrän, 2018). The advantages of biomass residues over cultivated biomass are manifold: they are significantly less expensive (Zahoransky, 2004), they do not require any cultivated land, and unlike energy crop cultivation, they do not require fertilizers or pesticides. The most sustainable approach to reducing the negative impacts of transport, especially emissions, is seen in a decentralized, regional, or local use of these resources for both energy use and heat generation (Hauser & Wern, 2016). However, whether or how sustainable the use of biomass residues and waste materials is in practice depends on logistical challenges because these materials are highly decentralized (DBFZ, 2011, 2015).

Governance innovations and actor landscapes of the German and North Hesse energy transition

In addition to technical innovations, the German energy transition is associated with considerable infrastructural, social, and economic shifts, which have led to considerable changes in the actors’ landscape (e.g. agricultural energy generation) and governance innovations (e.g. the emergence of citizen energy cooperatives, new forms of cooperation, municipal energy transition strategies; Moss et al., 2015). New energy actors are mainly based on regional and local scales, taking advantage of new legal conditions to begin with manifold, often niche initiatives; for example, municipalities reclaiming the operation of local power grids for feeding locally generated renewables into the grid, and the installation and operation of renewable power plants by regional actors, including citizen wind parks or farmers’ cooperation for the operation of biomass plants (Baasch, 2016). In the field of bioenergy, the role of farmers has changed significantly; they are not only active in the cultivation of energy crops, but they have also become energy generators themselves through the construction and operation of biogas plants.

With regard to governance aspects, the energy transition has led to a situation in which regions, towns, and villages are ‘experimenting with socio-technical innovations and aiming to implement new concepts have to develop governance structures under high uncertainty’ (Fuchs & Hinderer, 2014, p. 1). The North Hessian municipality of Wolfhagen, which is also one of the partner municipalities in the case study presented here, is an example of early municipal energy transition that has attracted regional, national, and international attention for both technical (Hartmann et al., 2018) and governance innovations (see Baasch, 2016; Bauriedl, 2016). Research on the success factors of the energy transition process in Wolfhagen shows that several factors were relevant, including the motivation of key stakeholders, the availability of technical knowledge, the window of opportunity (especially through legal and financial frameworks at the national level), local political support by a broad cross-party coalition, and a comprehensive participation process that has resulted not only in the establishment of a citizens’ energy cooperative, but also in the cooperative's co-participation in municipal utilities (Baasch, 2016). In a study on forms of local governance in the context of decentralized energy transition, Bauriedl (2016) also refers to Wolfhagen as an example of expansions of state control in the direction of network governance and market-oriented governance. However, state actors retain a prominent position in the energy transition processes, as they have legislative competence, democratic legitimacy, and implementation power. Nevertheless, this case study demonstrates that hierarchy and network can work together constructively (i.e. coordination in the shadow of hierarchy; Bauriedl, 2016, p. 88). These previous studies have focused on energy transition processes associated mainly with wind- and photovoltaic-based energy generation, as these have been prioritized for achieving the municipal goal of a 100% renewable energy supply. Since 2015, this goal has been achieved, and the focus has been on the topic of heat transition, in particular on cooperative solutions for a local heat transition, in which public and private buildings are to be supplied with regenerative heat from biomass residues in cooperation between the district and municipalities.

Case study: local and regional perspectives on bioenergy potentials from biomass residues

The previous review of the state of research on bioenergy in Germany points to two central aspects for the future sustainable generation of bioenergy: first, the primary importance of biomass residues and waste; and second, the importance of decentralized energy generation and thus the regional and local level. The starting point of this research was the question of (how) can residual and waste-based bioenergy contribute to a sustainable, decentralized energy transition? As previous studies point out, such biomass potentials are strongly decentralized and fragmented (Hauser & Wern, 2016); therefore, the municipal level is the most suitable starting point to address this question. Within a transdisciplinary research project [KlimaInnoGovernance – Cooperation of cities and surrounding areas for climate resilience: Governance innovations for the combined use of biomass and waste heat for energy provision], these potentials were investigated using the example of three rural municipalities in two districts (Kassel and Schwalm-Eder) of the North Hesse region. The project consortium included scientific partners with backgrounds in environmental studies (human geography, political science, environmental psychology, sustainability science, energy, and environmental science) as well as project partners from regional and municipal practice with technical, economic, and administrative expertize (energy consulting agency, local public administration). The research process followed an incremental procedure in which the research questions and knowledge needs were coordinated cooperatively between the scientific and practice partners, and then research results were discussed and processed. The aim was to generate both scientific findings and practical knowledge. The consortium included three municipalities (Figure 1), Hofgeismar (15,900 inhabitants), Felsberg (10,700 inhabitants), and Wolfhagen (12,900 inhabitants), all of which are 20–30 km away from the city of Kassel (201,600 inhabitants).

Figure 1. Location of the research area and municipalities: Hofgeismar, Wolfhagen, Felsberg.

The research municipalities are surrounded by agricultural and forestry land as well as nature reserves. With regard to renewable energies, Wolfhagen was a regional pioneering municipality for almost 30 years, starting in the 1990s with the first energy-efficient public buildings; by 2015, it has developed into a 100% renewable energy municipality (Baasch, 2016; Bauriedl, 2016). In contrast, the municipalities of Hofgeismar and Felsberg are still in the early stages of renewable energy transition. All project municipalities are using the research project to explore bioenergy potentials from sustainable biomass residue use, to establish or further develop actor networks and to generate knowledge through exchange with regional and local bioenergy actors and the scientific project partners. In all three project municipalities, there are already farm biogas plants, but their future operation is uncertain owing to the change in funding conditions. The data situation regarding biomass residues is difficult because there is no uniform or systematic recording of residue potentials for bioenergy. Existing databases on biomass residues and waste and their availability for the generation of bioenergy are characterized by strong methodological differences and are therefore not directly comparable (Brosowski et al., 2019). For this reason, interviews were conducted with local and regional stakeholders addressing the following questions:

1. How do the stakeholders assess the status quo and a possible increase in residual and waste-based bioenergy in the study region?

2. How is the availability of such bioenergy potentials evaluated and which barriers (e.g. legal, financial) or/and preconditions for their use (e.g. governance innovations) exist?

3. How are the chances of an expansion of local heating networks assessed?

4. What is the significance of residual and waste-based bioenergy as a contribution to the decentralized energy transition and how do they relate to ecological modernization approaches?

The interview partners were identified by a series of meetings held with regional cooperation partners involved in the biomass and waste management sector. The semi-structured qualitative expert interviews were conducted in 2020 and used open questions about the assessment of energetic biomass potentials, potential conflicts and obstacles of use, legal and funding framework, economic feasibility, constellations of actors, and governance arrangements. A total of 15 stakeholders were interviewed in 12 sessions from the following areas of operation: three involved in regional energy supply [ES 1–3], two regional authorities (waste law) [RA 1;2], one involved in regional waste disposal [WD], two involved in agricultural biogas plant operations (machinery ring) [MR 1;2], two involved in regional technical building management (responsible for local heating networks in public properties) [BM 1;2], one scientist from the field of biomass research [SC], one climate protection manager [CP], one municipal office for the environment [ME], one climate and energy consultancy [CEC], and one district forester [DF]. The interviews lasted from 40 min to 1.5 h, and the conversations were recorded and transcribed. In four cases, the conversation was simultaneously protocolled by the interviewers. The methodological approach was based on expert interviews (Gläser & Laudel, 2006, 2009; Meuser & Nagel, 2009a, 2009b). The interview transcripts were evaluated using qualitative content analysis (Mayring, 2014, 2015).

The results of the interviews are summarized in thematic blocks according to the research questions.

Evaluation of residue- and waste-based bioenergy in the region

Stakeholders agree that the majority of biomass residues are already being used in the region (both material and energy use pathways), and anticipate increasing competition for use in the future [INT ES 2; SC]. However, they disagree about which biomass residues still have usable potential for bioenergy in the region: some see potential (only) in woody biomass [INT CEC], others more in municipal green waste [INT ES 1] or in residues from the food industry and liquid manure [INT ES 2]. However, a significant increase in bioenergy potentials requires a change in the legal, economic, and procedural framework conditions; for example:

Municipal green waste has great potential for energy generation (in contrast to today's costly disposal), but processes and regulations would need to be changed. [INT ES 1]

Only the food industry and through liquid manure could achieve significant increases in substrate quantities. […] These approaches need appropriate support, otherwise they cannot be implemented economically. [INT ES 2]

Barriers and requirements for utilization of bioenergy potentials

The interview results reveal severe barriers to the expansion of residue-based bioenergy. These can be divided into a lack of specialized knowledge at the local level, legal, financial, and political framework conditions and structural barriers.

Lack of (specialized) knowledge at the local level

Compared with the operation of wind power and PV plants, the technical and professional requirements for the energetic utilization of biomass residues are significantly higher, as is the operation of biogas plants and heat networks. In practice, therefore, the negative effects of a lack of expertize or an overburden of local stakeholders such as citizens’ energy cooperatives are repeatedly evident. Three examples were provided in the interviews. First, the sale of the biogas plant and heating networks in the bioenergy village of Jühnde to a municipal energy supplier after the operation proved to be technically too demanding for the local stakeholders [INT ES 2]. Second, problems with the plant operation of wood chips due to the inferior quality of residual materials; here, the lack of expert knowledge about the usability of such materials in practice led to damage to incinerators [INT BM 1; 2]. Third, gaps in knowledge about the use of biomass residues in biogas plants, as the legal conditions currently prevent their use [INT ES 1; 2; CEC]. If the legal conditions were to change, corresponding technical studies would have to be carried out on suitable substrate mixtures [INT ES 1].

Barriers of legal, financial, and political framework conditions

Respondents share scientific criticism (Purkus et al., 2018) of a lack of a reliable national bioenergy strategy that ensures planning and investment certainty. They also criticize current subsidy schemes as an inefficient ‘patchwork’. For example, the subsidization of wood pellet heating systems is not linked to any obligation to renovate buildings for energy efficiency [INT ES 2; CP; CEC]. Additionally, the frequent revisions of legal regulations lead to considerable difficulties.

The support conditions and the legal basis for renewable energy change within short periods of time. This makes planning security more difficult, both for energy suppliers and for energy-generating farmers and citizens’ energy cooperatives [INT ES 2]. The stakeholders also share the view that the amendment of the EEG and the resulting reduction in support for biogas plants in 2014 has led to a stagnation that has persisted to this date, an effect that has also been evident in other regions (see above; Klagge & Meister, 2018). Currently, hardly any new biogas plants are being commissioned in the region, as the financial risk is too high for most farmers [INT ES 1; 2; 3; MR 1; 2; CEC]. A further obstacle is the strict legal classification of biomass and biomass residues, which are either classified as renewable raw material (NawaRo) or waste material. This classification determines the amount of feed-in tariffs and thus the profitability of biogas plants. From an ecological and technical point of view, it would make sense to also use harvest residues for biogas generation, which are legally classified as waste [INT SC; ES 1; 2]. However, owing to existing subsidy regulations, this is not currently economically feasible [INT ES 2]. In addition, the waste regulations and the classification of substrates differ in federal states [INT SC; ES 1].

Stakeholders from forestry and agriculture demand a broader social and political debate and societal negotiation processes on the goal of so called ‘climate neutrality’ and of sustainable regional production and material cycles [INT DF; MR 1]. In particular, it is important to accept that climate neutrality is not free [MR 1].

Structural barriers

The existing utilization paths are described as being highly fragmented and varying from municipality to municipality owing to ‘grown structures’ in the sense of very specific constellations of stakeholders [INT CEC; SC; ES 1; 2; 3; RA 1; 2]. The variety of biomass utilization paths also has an impact on the respective actor structures: the municipalities have very different disposal and collection structures, which are partly in municipal and partly in private hands [INT ME; RA 1;2]. This not only makes it difficult to compare and transfer approaches, but also makes inter-municipal cooperation for generating and utilizing marginal biomass potential more difficult [INT ME].

Opportunities and barriers for the expansion of local heating networks

The expansion of biomass-based local heating networks is confronted with a number of obstacles. Not only for the planning of biogas plants, but also for connected heating networks; long-term planning reliability (15 or 20 years) is required for economic reasons [INT ES 1; 2]. The lack of acceptance by potential heat consumers, especially private households, is seen as highly problematic [INT ES 3; CP; CEC]. At the local level, reliable contracts between heat consumers and biogas plant operators could increase planning security [INT CEC; CP]. The most reliable option is seen in the municipal building stock or larger residential units, as private households (individual houses) often decide at short notice on currently favorable supply options and may then fail as heat consumers [INT CEC; CP; WD].

Another barrier to the expansion of local heating networks lies in competing government subsidy programs. In 2026, the new installation of oil heating systems in private households will be banned in Germany. To facilitate the switch to more climate-friendly heating systems, individual pellet heating systems are currently being subsidized. Switching from oil to pellet heating systems is also a technically attractive option for homeowners because the remaining heating system can continue to be used except for the boiler [INT ES 2].

Regional bioenergy expansion in the context of decentralized energy transition and ecological modernization

Stakeholders show a clear preference for regional use strategies (biogas), which are considered the most sustainable and reliable option (short transport routes, independence from other states, and country states), even if the current political reality is contrary to this [INT MR 1]. The stakeholder interviews in the study region have shown that both agricultural and municipal actors as well as waste management do not usually pursue the energetic use of biomass residues with the aim of a local energy transition or ecological modernization, but rather focus on an economically favorable disposal of residues (especially sewage sludge and liquid manure) [INT ES 1; 2; 3; WD; MR 1;2; SC]. For this purpose, energy recovery is considered a possible disposal or intermediate treatment step, and the generation of energy and heat is not necessarily an independent goal [INT ES 1].

Conclusions

In general, this study shows that there are discrepancies between the expansion targets and optimistic assessments of bioenergy potentials by government agencies and research centers (FNR, 2017) and the assessments of regional actors. As there is no uniform approach to calculate the availability of biomass potential for different uses (Brosowski et al., 2019), the assessment of such potentials requires the inclusion of regional knowledge. Here, the statements of regional stakeholders show that the expansion potentials for residue-and waste-based bioenergy in the research area are generally estimated to be low. However, discrepancies exist with regard to the assessment of which potentials exist in the region.

The results of this study show that goals of ecological modernization are hardly relevant for regional actors in the field of bioenergy and heat transition. Although residue- and waste-based bioenergy and bio-based local heat networks are viewed positively in principle as part of the favored decentralized energy and heat transition strategies, the focus is more on finding cost-reducing more sustainable disposal and utilization strategies at the municipal level than on the development of new business areas, investments, or fundamental technical innovations. In addition, central basic conditions for ecological modernization are reliable and calculable framework conditions that create incentives for ecological practices (Jänicke, 2008). Until the amendment of the EEG in 2014, the legal and funding conditions in the context of the expansion of renewable energies in the research region were considered an important success factor for decentralized energy transition (Baasch, 2016); the opposite is true for the field of bioenergy and bio-based heating. As the interview results show, these basic conditions are by no means in place; instead, the current partly contradictory ‘patchwork’ subsidies and frequent changes to the EEG are barriers to an expansion of bioenergy in the context of energy and heat transition. Whether and how a bio-based heat transition goes hand in hand with governance innovations, which are of central importance in the context of the decentralized energy transition in Germany (Moss et al., 2015) and also in the research area (Bauriedl, 2016), cannot be answered at present owing to the strong fragmentation and differences in the field of bioenergy and bio-based heat. This will need to be the subject of future research.

In addition, it is primarily structural challenges that narrow approaches to decentralized heat transition strategies; the highly fragmented utilization paths, which vary from municipality to municipality, make it difficult to derive statements about promising utilization strategies and their conditions. What is needed is small-scale analysis of individual municipal utilization paths and their stakeholder networks in order to identify factors for more sustainable strategies.

Acknowledgements

This work was supported by the German Federal Ministry of Education and Research (BMBF) under grant number 03SF0550A.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by Bundesministerium für Bildung und Forschung, Germany [Grant Number 03SF0550A].

Notes on contributors

Stefanie Baasch

Stefanie Baasch is a senior researcher and scientific project coordinator at the Sustainability Research Center, University of Bremen. She completed her doctorate in geography at the University of Hamburg. Her research focus is on socio-ecological transformation, environmental governance, political ecology, environmental justice and participation. In the summer semester 2020, she was deputy professor for Integrative Geography at the European University Flensburg.