1. Introduction
The German government has set a target of achieving greenhouse gas neutrality by 2045 [
1]. A central goal of the energy transition is for renewable energies (RE) to account for at least 80% of gross electricity consumption by 2030 [
2]. In 2023, the share of renewable energy in gross electricity consumption was 51.8% [
3], indicating that a significant increase in power generation from RE is necessary. This share rose to 55.2% in 2024 [
4].
Given the limited number of controllable geothermal power plants in Germany and the fact that its hydropower potential is largely tapped, the expansion of renewable energy capacity will primarily come from wind and photovoltaic (PV) installations. Both wind and PV energy are classified as variable renewable energies, as their output cannot be directly controlled and fluctuates throughout the day and year. Without appropriate energy storage systems, the gap between the minimum and maximum power generated by photovoltaic and wind sources will increase as the number of these facilities expands. This growing disparity highlights the critical necessity for flexibility within the energy system [
5].
To ensure this flexibility, it is essential to introduce flexibility in consumption across different application areas. One important area is the cooling of various products and processes. In 2017, electricity consumption for cooling systems in Germany was 73
, representing 14% of total electricity consumption [
6]. This demand is distributed across a variety of sectors with different consumption profiles and operational characteristics. For example, air conditioning in buildings and vehicles consumed around
. Industrial cooling processes (excluding food production) represented another significant share with
, and supermarket refrigeration consumed
. These examples highlight the diversity of cooling applications and underline the importance of considering sector-specific requirements and barriers when discussing flexibilization potentials. This substantial demand for electrical energy presents a significant opportunity for load management within the power grid. Cooling systems are integral to the supply infrastructure, allowing them to dynamically adjust both their cooling capacity and energy consumption, thereby contributing to grid stability. Additionally, by storing surplus renewable electricity as heat or cold during high generation periods, these systems support the integration of renewable energy from wind and photovoltaic sources and help mitigate generation peaks [
7].
The importance of cooling systems in the context of load management is increasingly acknowledged. The cooling sector’s significant contribution to Germany’s total electricity demand makes industrial cooling supply systems a promising option for scalable flexibility solutions. Their capacity to manage loads and optimize energy consumption makes cooling systems a valuable tool for the implementation of demand-side management strategies [
7].
In the past, several research projects have addressed the flexibilization of cooling supply systems, ranging from Night Wind [
8] (2006–2008) and eTelligence [
9] (2008–2012) to more recent initiatives such as FlexKaelte (2019–2022) [
10], FlexKälte (2020–2023) [
11], and BlueMilk (2018–2022) [
12]. All of these projects concluded that flexibility within cooling supply systems exists and that it presents opportunities for greenhouse gas reduction. Therefore, the ongoing research project FlexBlue (grant number 03EN6035A), within which this paper was developed, aims to further explore this topic and derive actionable recommendations that will encourage widespread implementation and mobilize the potential. As part of the project, an attempt was made to identify implementation examples, which proved to be highly challenging, with only a few cases found. Due to this discrepancy between potential and lack of implementation, it is crucial to examine the existing barriers. A key research objective is to understand what limits the implementation of flexibility and what solutions could help overcome these challenges. To achieve this, a survey will be conducted to obtain relevant feedback from a wide range of stakeholders within the value chain, as shown in
Figure 1. The aim of this approach is to identify the barriers specific to each stakeholder and to provide a comprehensive overview of the problems encountered, ultimately serving as the basis for formulating actionable recommendations.
2. State of the Art
2.1. Definition of Flexibility
The scientific literature offers a variety of definitions of flexibility in energy systems. However, flexibility can be generally understood as the ability to respond to changes in demand. This is evident in the works of various authors [
7,
13,
14,
15,
16,
17], all of which highlight the importance of responsiveness to demand fluctuations. Further definitions of flexibility of different authors are summarized in [
18]. These discrepancies illustrate the complexity and multifaceted nature of the subject matter, as the concept of flexibility is interpreted in diverse applications and under disparate conditions. A precise definition is essential for an accurate understanding of the role of flexibility in energy generation and utilization.
In this paper, flexibility is understood according to the definition in [
18]:
“Flexibility is the capability of an energy system to undergo temporary, reversible, and expectable changes to fulfil a specific goal over a certain period in reaction to an external signal.” Specifically applied to cooling supply systems, this means that the operation of the chiller—which uses electricity to generate cooling—deviates from normal operation for a certain period of time in response to an external signal. In normal operation, the chiller would generate exactly as much cooling as is demanded at any given time. In contrast, the flexible operating mode follows a signal, which can be the electricity price or CO2 emissions of the electricity supply, for example. Flexibility serves, for example, as an instrument to generate monetary benefits in companies, to reduce CO2 emissions associated with the electricity purchased for cooling or, if necessary, can also be used as an opportunity to reduce grid constraints resulting from the volatile feed-in of renewable energies. This can also provide monetary benefits to companies by reducing network costs.
Flexibilization refers to the adaptation of a system or facility to enable it to provide flexibility. In the context of cooling supply systems, flexibilization means modifying the system in such a way that it can temporarily adjust its electricity consumption in response to external signals (e.g., price or CO2 intensity), without compromising overall cooling requirements. This may involve, for example, the integration of thermal storage, adjustments to control strategies, or changes in operational planning.
If there is a high supply of electricity from renewable energies, this results in low electricity purchase prices on the electricity exchange and is generally accompanied by low CO2 emissions. At these times, the chiller should operate at the highest possible output, while the cooling not utilized by the cooling application is stored. A cold storage unit is used for this purpose, or the storage capacity for the refrigerated goods to be stored is utilized. In the case of high prices on the electricity exchange with a low supply from renewable energy sources, the chiller is reduced or ideally switched off. In these phases, the cooling demand is covered by the implemented cold storage system so that the cooling that is required for the cooling application is always reliably available.
2.2. Flexibilization Strategies of Cooling Systems
Given the challenges associated with decoupling cooling demand and generation, the implementation of innovative technologies and strategies is essential. The integration of thermal storage is one of the most promising methods to achieve this decoupling. Thermal storage allows cooling to be generated when energy costs are low, and then the stored cooling can be used when needed, as described in the previous subsection.
Sensible and latent cold storage systems can be used for cold storage. In sensitive cold storage systems, water or a water/glycol mixture is used as a refrigerant and storage medium. The supply and extraction of thermal energy is noticeably felt in sensitive storage systems through a change in temperature. Latent cold storage utilizes the phase change of the storage medium. This means that during a phase transition, heat is added to or extracted from a storage medium without a noticeable change in temperature. Ice storage represents a form of latent cold storage system. Another possibility is the use of macro-encapsulated phase-change materials.
An alternative option is taking advantage of the inherent storage capacity of certain commodities or conditioned spaces, such as deep-freeze warehouses for food items. By utilizing temperature changes, energy can be stored and released in these materials, allowing for a flexible supply of refrigeration. This study focuses on the flexibilization of electrically operated cooling systems. However, it should also be mentioned that there are thermally driven systems for cold generation as well. Whether these can be used for flexibility in the sense described here depends on which heat source they use. If waste heat is used as a heat source for refrigeration production, this would represent a very environmentally friendly way of generating cooling, but due to the lack of coupling to the electrical energy system, no flexibility can be provided for this. When using a combined heat and power (CHP) plant for combined heat and power generation, the CHP plant can be used as a flexible facility [
10].
The following section describes several studies about the flexibilization of cooling supply systems and cooling applications. This is not an exhaustive list, as more studies exist. Cooling applications can be categorized into the following areas: process cooling, product storage, and air-conditioning [
19].
In the study by Stöckl et al. [
20], the authors investigate the flexibility potential of a cold storage warehouse for dairy products as a case study of flexibility in product storage. The cooling capacity of the storage facility is adjusted by modulating the air temperature. The stored products respond to these adjustments by undergoing temperature changes within a predefined temperature range, effectively serving as an inherent thermal cold storage. The flexibility of the cold storage facility must be evaluated in the context of the overall cold chain to ensure compliance with quality and safety standards.
The study presented by Howard et al. [
21] serves as an example of flexibility in process cooling. In this study, production and cooling processes for canned meat are analyzed using a custom-developed multi-method simulation. Another example of process cooling in the food industry was examined by von Hayn et al. [
22]. Here, the flexibility of various cooling processes in beer production is investigated. Beer production is particularly well-suited for flexibility measures, as it inherently incorporates multiple energy storage systems, with beer itself also functioning as an inherent thermal buffer. Repke et al. [
23] explore the use of products as thermal storage in cold storage warehouses to minimize electricity costs. The air temperature is adjusted based on electricity price forecasts, allowing only minor fluctuations. The highest savings are achieved when the temperature is set to the upper permissible limit, though this may affect the stored products. Similarly, Svane et al. [
24] examine the use of frozen meat as thermal storage. Their results also indicate significant cost savings, especially with longer forecasting periods. However, they highlight that while warehouse operators aim for flexibility, they often lack the necessary data and expertise.
In the study by Khorsandnejad et al. [
15], the variation of electricity consumption by the cooling system in a cold storage warehouse is analyzed with the objectives of reducing electricity costs, lowering greenhouse gas emissions, and mitigating peak loads. The reduction in electricity costs and greenhouse gas emissions is based on the dynamic nature of electricity prices in the market and the specific emissions associated with electricity procurement from the public grid, which fluctuate due to the variability of renewable energy generation. Unlike the approach by Stöckl et al. [
20], a dedicated thermal energy storage system is utilized instead of leveraging the stored products as inherent thermal storage.
Laband et al. [
7] focus on the inherent thermal flexibility of cooling systems for air-conditioning. Their research is focused on investigating the impacts of diverse cooling demand profiles on flexibility, with the objective of demonstrating how these systems can contribute to the stability of the power grid. The study aims to quantify and classify the flexibility of cooling systems by analyzing a range of characteristics, including cooling demand profiles and storage sizing. From a methodological perspective, their research entails an examination of various cooling demand profiles and their impact on flexibility.
In the German energy market, there are market mechanisms available both to reduce costs and to increase profits. Cost reduction can, for example, be achieved by optimizing electricity procurement in the day-ahead and intraday markets or by minimizing grid charges. Examples of profit-increasing mechanisms include providing system services, such as offering positive or negative balancing power [
25].
2.3. Literature Overview of Existing Barriers
In order to gain insight into the barriers faced by stakeholders in the flexibilization value chain as part of the ongoing transformation toward greater flexibility, a comprehensive literature review has been conducted. Existing literature includes studies and reports [
26,
27] that provide broad overviews of flexibility in general and of common barriers as well as literature that primarily focuses on barriers in industrial companies, the manufacturing sector, and the trade, commerce, and services sector [
28,
29,
30]. Additionally, some studies specifically examine cooling applications [
31] or include the barriers and perspectives of transmission system operators (TSO) and distribution system operators (DSO) [
32]. The identified barriers are primarily associated with operators of cooling systems and cooling applications in the context of the flexibility definition used, i.e., barriers from the literature that do not apply to the relevance of cooling systems, their flexibilization, or to the definition used are not included. However, it is important to note that there are additional stakeholders within the value chain, which are illustrated in
Figure 1. Flexibilization value chain in the context of electrical consumers and producers refers to the coordinated effort of multiple stakeholders across the entire value chain to enable flexible energy consumption and generation. The aim is to optimize energy usage, integrate renewable sources more effectively, and provide flexibility for the energy system. Besides operators of cooling systems and cooling applications, the value chain includes other stakeholders such as planning offices, virtual power plant operators, manufacturers of refrigeration machines, and thermal storage. The stakeholders referenced in existing literature are depicted in orange. The stakeholders that have been additionally identified—and for which no barrier analysis has yet been conducted—are shown in blue. Furthermore, a single barrier may be attributed to multiple stakeholders, which has been taken into account in the subsequent stages of the investigation.
It became evident that a significant number of stakeholders are not considered at all in the existing literature regarding their barriers. This gap in the literature highlights the necessity for further research and leads to the decision to conduct a survey in order to reach additional stakeholders in this area to identify reservations regarding the implementation of flexibilization measures. The barriers identified in the literature are illustrated in the subsequent
Table 1,
Table 2,
Table 3,
Table 4,
Table 5,
Table 6 and
Table 7.
In some cases, barriers have been assigned to new categories that the authors consider relevant and may not necessarily reflect the categorizations found in the original sources. Barriers are classified into the following categories: economic, regulatory, technological, organizational, behavioral, informational, and competence [
28], which are explained in more detail below using selected but not exhaustive examples.
Economic barriers encompass factors related to the financial aspects of flexibilization, e.g., high investment costs and inadequate profitability. These barriers can prevent companies from investing in flexible systems, as the economic benefits are often not clearly evident.
Regulatory barriers pertain to the legal framework, which may be restrictive or complex in nature. This includes the lack of access to variable electricity prices and the high costs associated with pre-qualification, which present significant challenges to the implementation of flexibility solutions.
Technological barriers are technical challenges that impede the implementation of flexible systems. Such risks include those related to the technical aspects of production, the potential for a reduction in product quality, and the high demands placed on information technology (IT) infrastructure.
In the category of organizational barriers, internal barriers within companies are explored, highlighting challenges in adopting flexibilization measures. Significant factors include insufficient acceptance among staff and a failure to adequately prioritize energy efficiency efforts.
When considering behavioral barriers, the emphasis shifts to how human attitudes and behaviors obstruct the implementation of flexibilization measures. Psychological, social, and habitual factors play a critical role in shaping resistance to change and innovation within both individuals and groups.
For informational barriers, the primary concern is the lack of sufficient knowledge or clarity that prevents progress toward flexibility. Uncertainty surrounding future market trends, such as regulatory updates, price dynamics, and financial outcomes, creates barriers to effective planning and decision-making.
In addition, competence barriers include the lack of expertise or knowledge, e.g., about the production processes or technical aspects, and resources within the organization, and are therefore unable to identify and capitalize on the potential for flexibility inherent in their systems.
The literature review demonstrates that a comprehensive array of barriers has been documented. However, as illustrated in
Figure 2, the existing studies primarily focus on the manufacturing sector and the trade, commerce, and services sector, with minor attention to grid operators, while all other stakeholder groups have been neglected. To fully capture the range of barriers, a targeted survey encompassing all stakeholder groups will be conducted.
3. Materials and Methods
To identify barriers and experiences in the flexibilization of cooling supply systems along the value chain, a survey was conducted, and multiple discussion groups were held.
3.1. Design and Realization of the Survey
In addition to the literature review, which only focuses on specific stakeholders, the questionnaire aims to provide a comprehensive barrier analysis covering all stakeholders involved in the flexibilization value chain. The approach involves designing a single questionnaire applicable to all stakeholders, structured as follows:
General Information;
Experience with Flexibilization;
Motivation and External Pressure to Act;
Impact Strength;
Barrier Analysis;
Recommendations for Action.
General Information: The questionnaire starts with 5 general questions, focusing primarily on participants’ self-identification as one or more stakeholders in the flexibilization value chain.
Therefore, the barriers faced by these different stakeholders need to be considered in order to ensure a comprehensive and effective implementation of flexibilization measures. The industry sector is inquired in the questionnaire; as barriers and incentives for cooling system flexibilization can vary between sectors. Additionally, participants are asked about their company size and department.
Experience with Flexibilization: Participants are asked whether they have experience with the flexibilization of cooling supply systems. Based on a simple distinction (yes/no), follow-up questions are tailored accordingly. Such inquiries encompass an examination of the underlying factors that contribute to positive experiences, as well as an investigation into the circumstances that lead to the absence of such experiences in individuals who have not yet had the opportunity to experience them. Additionally, participants are asked about any challenges encountered and what could have improved the outcome. This approach helps differentiate between those with practical experience and those who have only considered flexibilization without implementation, or whose previous implementations were discontinued. Subsequently, the results may be subjected to further analysis with a view to identifying common problems or exemplars of best practice. The reasons for why flexibilization has not been implemented, or the issues that led to the discontinuation of efforts, are also explored.
Motivation and External Pressure to Act: Subsequently, participants are queried regarding their motivation for pursuing flexibilization, e.g., cost reduction, regulatory compliance, operational reliability, and the external pressures that have influenced the implementation of such measures, e.g., government policies, market competition, and stakeholder expectations. This allows for an evaluation of the external pressures on participants and an estimation of the relative importance of the barriers identified.
Impact Strength: Furthermore, participants are requested to evaluate their impact strength. In this context, the term “stakeholder impact strength” is used to describe the degree of influence a particular stakeholder has in implementing flexibilization, in comparison to the influence of other stakeholders. This assessment allows for the weighing and categorization of the identified barriers, affording greater weight to those faced by stakeholders with a higher level of influence while still considering all barriers.
Barrier Analysis: Participants are requested to select from a list of predefined answer options and to provide an open-ended response indicating their primary barrier.
Recommendations for Action: Furthermore, participants are requested to offer practical recommendations for action that would facilitate the implementation of flexibility solutions. This facilitates the identification of necessary improvements and areas in which additional assistance is required.
3.2. Data Analysis
In the course of the investigation, the relevance of the conducted survey was initially evaluated to ensure that the collected data would yield meaningful and valuable insights, thus justifying the research project as a whole. Subsequently, a canonicalization procedure was conducted to ensure a uniform representation of the responses. This approach transformed the data into a standardized, uniform format, creating a foundation that enables consistent comparisons and insightful analyses. This stage was of great importance in enhancing the quality of the data and preventing bias in the subsequent analysis.
Following the canonicalization process, the collected responses were subjected to a systematic review and categorization in accordance with the established methodology. Thematic categorization is employed to organize related terms under broader categories. To illustrate, terms such as “low savings potential,” “uncertainty about returns,” and “lack of flexible electricity tariffs” are grouped under the category of economic viability. The categorization process allowed for the identification of patterns within the dataset, thereby enabling a differentiated analysis of the results. The categorization of responses also facilitated an understanding of the diverse perspectives of the respondents, which in turn enabled a more detailed and nuanced evaluation.
In the final stage of the process, a statistical analysis was conducted on the categorized responses. This analysis entailed the collation of frequencies pertaining to individual results, in addition to the calculation of percentage shares in relation to the population. By employing this methodological approach, a robust interpretation of the results was achieved, which can serve as a foundation for further discourse and conclusions.
It is important to note that the composition of the respondent base may vary across questions due to the implementation of branching logic. Additionally, some open-ended questions were optional and therefore not answered by all participants. Consequently, the scales of the axes differ accordingly.
3.3. Discussion Groups
Discussion groups were utilized to identify and thoroughly examine the key barriers to the implementation of cooling flexibilization measures. The groups comprised a diverse array of stakeholders, each contributing unique perspectives and expertise to the discourse. In addition to the researchers leading the discussion groups, the following stakeholders were involved:
Manufacturers of refrigeration machines;
Planning and Design of cooling supply systems;
Manufacturers of cold thermal energy storage;
Planning and Execution of Maintenance;
Data center operators representing cooling applications;
Cooling system operators;
Distribution network operators;
Electricity suppliers;
Metering point operators;
Representatives of associations;
Virtual power plants.
The discussions addressed several key topics, including the involvement of additional stakeholders in the flexibilization value chain and the barriers associated with each of these stakeholders. The objective of these discussions was to gain a more comprehensive understanding of the value chain and to identify the specific challenges that can be attributed to each stakeholder.
5. Discussion and Conclusions
The present study highlights significant interest from companies across the entire process chain in increasing the flexibility of cooling supply systems. This interest stems from the potential benefits, including reductions in energy costs, increased efficiency, and enhanced transparency through improved access to system data. However, achieving these benefits on a broader scale requires overcoming numerous challenges and barriers.
Figure 10 shows the new barriers identified in this study, broken down by survey and discussion groups, compared to the barriers from the literature for the seven categories. Barriers that were already present in the literature are counted as literature, even if the barrier was also mentioned in this study. Ninety-eight barriers were taken from the literature. This study provided 128 barriers, 39 of which were already present in the literature, i.e., 89 barriers were identified as new. In total, there is a list of 187 barriers that are relevant for the flexibilization of cooling supply systems.
The results show that the focus on refrigeration supply systems and the extension of the stakeholders to the flexibilization value chain provided new insights.
These new 89 barriers can be categorized as follows: 18 instances are of a technological nature (20%), 18 are economic (20%), 15 are regulatory (17%), 11 relate to competences (12%), 9 are behavioral (10%), 9 are informational (10%), and 9 pertain to organizational aspects (10%).
The present findings raise the following key aspects:
Economic barriers: For a cost–benefit analysis, both the effort and the benefits must be quantified. However, for some companies, this can be challenging, as both factors are highly dependent on individual circumstances. In particular, there is a lack of studies and generalizable data on investment costs, making it difficult to assess the required effort.
Technological challenges: The high complexity of integrating flexible systems into existing infrastructures shows that there is a lack of standardized solutions. Companies need clear technical guidelines and support to reduce uncertainty.
Regulatory uncertainties: The complexity of the legal framework and access to flexible electricity pricing models must be simplified. It is critical that policymakers create clear and consistent guidelines to facilitate implementation by companies.
To ensure broader implementation of flexible cooling systems, an integrated approach is essential. The following actions are recommended:
Showcase successful implementations by utilizing examples such as living labs, role models, and practical experiences to convince decision-makers of the feasibility and benefits of flexible systems. Highlight supply and process security to increase confidence in adoption.
Provide verifiable economic calculations to demonstrate cost-effectiveness, particularly for projects commissioned by customers. Establish financial assistance programs for essential investments, ensuring that costs and benefits are transparent and comprehensible.
Simplify implementation through standardization, digitalization, and turnkey concepts to minimize personnel and cost efforts.
Ensure easily accessible information, such as guidance on flexible electricity tariffs, to improve understanding and encourage adoption.
Address regulatory barriers, such as the complexity of existing frameworks and limited access to time-variable electricity pricing. Integrate flexibility measures into standards like ISO 50001 to complement efficiency initiatives.
Promote acceptance among employees and decision-makers by emphasizing the tangible benefits of flexible systems. Provide targeted technical training to build competence and support the adoption of novel technologies.
Addressing the identified barriers requires collaboration between policymakers, businesses, and research institutions. Policymakers must focus on regulatory reform to streamline implementation and enable access to flexible energy solutions. At the same time, businesses and researchers must work together to develop and demonstrate practical, cost-effective solutions that can serve as benchmarks for success.
Further investigation into stakeholder-specific barriers is crucial for developing tailored recommendations. A deeper understanding of the unique challenges faced by various stakeholders will enable the formulation of bespoke strategies to overcome these barriers effectively.
The findings of this study illustrate the necessity for an integrated approach to successfully promote the flexibilization of cooling systems. By addressing technological, economic, regulatory, and behavioral barriers in a coordinated manner, the potential benefits of flexible cooling systems—such as reduced energy costs, greater efficiency, and improved transparency—can be realized. Collaboration among key stakeholders will be pivotal in overcoming these challenges and fostering the acceptance and widespread implementation of flexible cooling solutions.
The results are based on a relatively small sample of 52 companies and can therefore only be generalized to a limited extent. In addition, it should be noted that certain stakeholder groups, such as energy service providers (e.g., electricity suppliers or traders), are underrepresented or not represented at all (e.g., regulatory authorities). This is due to the nature of the data collection: the study was based on an online survey in which every valid response was included. Given the relatively small number of responses, no selection process was applied. As a result, the dataset reflects only those stakeholders who actively chose to participate, and some key groups did not respond. This limitation should be addressed in future research through targeted outreach or stratified sampling. To strengthen the findings, individual interviews with key actors should be conducted, as they allow for follow-up questions and enable a more nuanced interpretation of the results. Furthermore, the group discussions should ideally be repeated with a larger and more diverse set of participants, for example, through a public event or open forum, to capture a broader spectrum of perspectives and increase the robustness of the conclusions.
Furthermore, part of the analysis is based on open-ended responses and self-assessments by participants, which implies a certain degree of subjectivity and room for interpretation. Future work should complement this with quantitative, representative analyses and more in-depth case studies. While the survey results indicate a strong motivation among participating companies to enhance the flexibility of their cooling systems (see
Figure 5), this finding should be interpreted with caution. It is likely that companies with little or no motivation in this area were also less inclined to take part in the survey. This could lead to a response bias, where the reported level of motivation is higher than what would be observed in a fully representative industry-wide assessment.
A more comprehensive study covering a broader sample of companies, including those that may not actively seek improvements in cooling flexibility, would help to validate these findings and provide a more balanced perspective on the overall industry sentiment.
The focus group and the online survey were not intended to validate or replicate each other but rather to complement one another by capturing different stakeholder perspectives. As barriers to flexibilization are inherently subjective and context-specific, differences between the two methods are to be expected and are not necessarily contradictory. Each method contributed distinct insights: the focus group allowed for in-depth discussion and exploration of interdependencies, while the survey enabled broader coverage across the cooling value chain. Although full triangulation of findings was not conducted, the combination of methods provides a more comprehensive picture. Future research could build on this foundation by applying structured cross-validation techniques to systematically explore potential overlaps and contradictions.
While this study focused on identifying and categorizing a broad range of barriers across the flexibilization value chain, the degree of influence of each barrier was not quantified. Future research should aim to assess the relative impact and prioritize the identified barriers, for example, by applying methods such as the Analytic Hierarchy Process (AHP) or MaxDiff scaling. This would support a more targeted development of measures to overcome the most critical barriers.
Additionally, a comparison between Germany and other countries could provide valuable insights into how similar barriers are addressed in different policy and energy system contexts. Learning from international approaches may help identify strategies to overcome certain barriers more effectively.