Sustainability Assessment of Energy System Transition Scenarios in Gotland: Integrating Techno-Economic Modeling with Environmental and Social Perspectives

Abstract

Gotland has been designated by the Swedish government as a pilot region for the transition to a sustainable, fossil-free energy system by 2030. This transformation emphasizes local renewable energy production and system independence. Within this context, this study investigates the role of industrial waste heat as a resource to improve energy efficiency and support sector integration between electricity, heating, and industry. A mixed-methods approach was used, combining techno-economic energy system modeling, life cycle assessment, spatial GIS data, and stakeholder input. The study develops and analyzes future carbon-neutral energy scenarios for Gotland’s energy system. Industrial waste heat can significantly reduce primary energy demand, particularly in scenarios with expanded industry, carbon capture, and increased sector integration—such as through district heating. In such cases, up to 3000–4000 GWh/year of low-temperature industrial residual heat becomes available, offering substantial potential to improve overall energy efficiency. The scenarios highlight synergies and trade-offs across environmental, economic, and social dimensions, emphasizing the importance of coordinated planning. Scenarios with offshore wind enable energy exports and industrial growth but raise challenges related to emissions and public acceptance, while scenarios without cement production reduce environmental impact but weaken local economic resilience. Limitations of the study include the exclusion of global supply chain impacts and assumptions about future technological costs. The study underscores the need for integrated planning, regulatory innovation, and stakeholder collaboration to ensure a just and resilient transition for Gotland.

1. Introduction

The transition to sustainable energy systems is a central challenge in addressing the global climate crisis, enhancing energy security, and promoting long-term economic and social resilience [1,2]. As the energy sector accounts for a major share of global greenhouse gas emissions, its transformation is critical to meeting international climate targets such as those outlined in the Paris Agreement. Achieving this transformation requires not only the substitution of fossil fuels with renewable sources but also systemic changes that promote efficiency, flexibility, and integration across sectors such as electricity, heating, transport, and industry [3,4]. These changes must be inclusive, addressing social equity, regional participation, and ecological integrity—factors often overlooked in purely techno-economic planning processes [5,6,7].

Island regions offer unique opportunities as living laboratories for sustainable energy innovation. Their geographic isolation, finite resources, and clearly bounded systems make energy transitions both more urgent and more manageable. Islands can serve as microcosms for testing technical solutions, governance models, and collaborative frameworks under real-world conditions [8]. Insights from such transitions are often transferable to national and regional policy-making [9]. A growing body of literature has examined island energy transitions, with notable case studies in Samsø, El Hierro, and Hawaii focusing on renewable energy integration, local governance, and community participation [10,11,12]. However, most of these studies concentrate on electricity and storage systems, with limited attention given to industrial sector integration or the utilization of residual heat, which is a central focus of the present work.

In this context, Gotland—Sweden’s largest island—has been designated as a national pilot region for a fossil-free and resilient energy transition by the Swedish Energy Agency [13]. The Gotland Energy Pilot roadmap [14] and the Gotland Region Development Strategy [15] jointly expressed a vision for an energy transition that is not only climate-neutral but also aligned with broader sustainability goals. Major planned transformations include expansion of renewable electricity (e.g., offshore wind), improved grid infrastructure, and the development of hydrogen and electrofuel production, as well as carbon capture from industrial processes. These developments present significant opportunities for sector integration and resource efficiency—particularly through the reuse of industrial waste heat, which has received limited attention in prior island studies.

These include strengthening local resilience, ensuring social inclusion, fostering economic innovation, and minimizing ecological impacts. In line with this vision, Gotland’s energy system is undergoing major planned transformations, such as the expansion of renewable energy generation, improved grid infrastructure, development of hydrogen and electrofuel production, and carbon capture from industrial processes. These changes offer opportunities for greater efficiency and resource optimization—particularly through the integration of heating, electricity, and industrial sectors and the utilization of residual heat from existing and future activities.

The core objective of this study is to assess the role of industrial residual heat in enabling an efficient, flexible, and sustainable heating sector that supports Gotland’s broader energy transition goals and to investigate how the heating sector in Gotland can be developed to better utilize and integrate existing and planned energy resources, and to analyze how this can contribute to a sustainable, competitive, and self-sufficient island energy system [13]. To achieve this, we pursue two extended objectives:

To apply techno-economic energy system modeling (TIMES-Gotland) to explore optimized, fossil-free transition pathways that include electricity, heating, and industry [16];

To conduct a multidimensional sustainability assessment of these scenarios, evaluating trade-offs and synergies across environmental, social, and economic dimensions (in the current paper).

Furthermore, several model scenarios are investigated that integrate a range of energy and industrial development choices based on different technology choices, energy resource availabilities, and sectoral linkages. These scenarios form the baseline for the sustainability assessment, which explores how each pathway aligns with or diverges from Gotland’s broader sustainability goals. The paper also investigates the environmental, economic, and social trade-offs of various energy transition scenarios and explores their implications for sustainable regional planning. In fact, by combining scenario-based modeling with multidimensional sustainability analysis, this paper offers a thorough evaluation of Gotland’s energy transition strategies. The findings aim to inform regional decision-makers, facilitate cross-sectoral collaboration, and provide transferable insights for pursuing ambitious sustainable energy goals.

2. Methodology and Scenarios

2.1. Method

This study employs a mixed-methods approach to assess the sustainability of different transition scenarios for Gotland’s energy sector. The methodology integrates techno-economic energy system modeling (presented in [16]), environmental life cycle assessment, and social sustainability evaluation, supplemented by stakeholder engagement and spatial analysis. Together, these methods provide a holistic understanding of how Gotland can transition to a sustainable, fossil-free energy system by 2030 and beyond.

2.1.1. Scenario Development

Four scenarios were developed to explore alternative pathways for Gotland’s energy system up to 2050. Scenario development began with a comprehensive mapping of the current energy system and identification of planned developments. Geographic Information System (GIS) tools were used to visualize heat demand and density across building types and regions, supporting both qualitative scenario formulation and subsequent modeling [13]. The scenarios were constructed based on two key variables for energy system scale (small-scale versus large-scale solutions) and grid connection, including island-based (stand-alone) versus connected to the mainland via a new cable. These matters yielded four main scenarios, reflecting Gotland’s energy system characteristics. The scenarios were developed collaboratively with project partners and were aligned with Gotland’s climate neutrality goals, regional development strategies, and sustainability ambitions (described in more detail in Section 2.4).

2.1.2. Techno-Economic Energy System Modeling

The TIMES-Gotland model, a dynamic, bottom-up optimization tool, was developed to simulate the energy system’s evolution from 2020 to 2050. Input data were compiled from national statistics; stakeholder inputs; and project-specific assessments of renewable potential, fuel prices, technology lifetimes, and demand trends. Key assumptions—such as technology cost trajectories, availability of waste heat, and industrial energy demands—were scenario-specific and documented in detail in [13]. The TIMES model minimizes total system costs while satisfying energy service demands, including heating, electricity, and emerging demands such as hydrogen and ammonia production. The model encompasses the following features:

• Sectoral integration: Electricity, heating, buildings, and industry.
• Regional granularity: Gotland is divided into six sub-regions, further segmented by building density to capture district heating cost variability.
• Temporal resolution: A total of 672 time segments per year, allowing for seasonal and intraday variation analysis.
• Technology database: Input data for renewable and conventional technologies, efficiency factors, cost assumptions, and fuel prices.

Residual heat availability was estimated through a combination of stakeholder engagement and standard calculations. For instance, food stores were assessed using standard floor area energy benchmarks, while cold-storage food producers and greenhouse operators provided site-specific information. A dialogue with the company Wa3rm (Malmö, Skåne County), helped evaluate heating needs for potential large-scale greenhouses near industrial heat sources.

The feasibility of utilizing residual heat was assessed not only in terms of availability but also in geographic proximity to heat demand centers. Many of the identified residual heat sources, such as food storage facilities and greenhouses, are located near urban or semi-urban areas with moderate to high heat demand, particularly in Visby and Slite. In some cases, these sources are within a few kilometers of the existing district heating networks, which could facilitate integration with limited pipeline expansion. However, in more dispersed areas like LGN and ROM (Figure 1), residual heat sources are located farther from demand clusters, which require significant infrastructure investment for heat transmission. This assessment was supported by spatial analysis using GIS layers of infrastructure and demand density. More details about the GIS layers and energy system modeling were provided in [16].

Furthermore, two primary scenario variables—system scale (small vs. large-scale solutions) and grid connection (islanded vs. mainland-connected)—were chosen based on their relevance to regional policy discussions and their systemic influence on Gotland’s energy future. Small-scale systems reflect local energy autonomy and distributed production, while large-scale systems enable centralized infrastructures like offshore wind and hydrogen export. Similarly, grid connection status shapes both technical feasibility and energy security, and is a core point of regional planning debate. These variables were identified as critical during stakeholder engagement and align with the transition levers described in the Gotland Energy Pilot Roadmap and regional development strategy.

2.1.3. Sustainability Assessment Framework

To evaluate the broader implications of each energy transition scenario, a sustainability assessment was conducted using a participatory and multi-criteria approach. The assessment focused on three dimensions—environmental, social, and economic—with the latter embedded in the TIMES model’s cost optimization that was presented in [16], while the environmental and social assessment modeling are presented in the current paper. Key sources for identifying relevant indicators included the following [15,18,19,20]:

Agenda 2030 Sustainable Development Goals (SDGs);

Sweden’s Environmental Objectives;

Gotland’s Regional Development Strategy;

Doughnut Economics and Social LCA frameworks.

Indicators were assessed using a five-point scale, comparing each scenario to the baseline. Quantitative data were used where available; otherwise, qualitative assessments were informed by stakeholder input. The five-point scale used for the sustainability assessment ranged from −2 to +2, where

+2 indicates a strong positive impact compared to the baseline;

+1 indicates a moderate positive impact;

0 indicates no significant change;

−1 indicates a moderate negative impact;

−2 indicates a strong negative impact.

These ratings were assigned based on quantitative indicators where available, and supplemented by qualitative stakeholder assessments and expert judgment when necessary.

Environmental Sustainability

Environmental impacts—including global warming potential (GWP), eutrophication potential (EP), land use, water use, and resource use (minerals and metals)—were assessed through life cycle assessment (LCA) in accordance with ISO standards. The assessment covered key technologies such as electricity and heat production, hydrogen and ammonia generation, cement production with carbon capture and storage (CCS), and greenhouse agriculture. The environmental footprint (EF) 3.1 method was applied using the GaBi software, Version 10.9 (LCA for Expert), incorporating data from the Ecoinvent and Sphera databases. Key impact categories included climate change, resource depletion, and ecotoxicity. LCA input data were sourced from the TIMES-Gotland model outputs for the year 2040.

Social Sustainability

Social impacts were evaluated through semi-structured interviews with local stakeholders, including industry representatives, public authorities, residents, and associations. Key themes explored included job creation and employment quality, social acceptance of new technologies, local collaboration and governance, and Gotland’s regional attractiveness. The number of jobs considered in the analysis reflects those created under each energy transition scenario. The job creation factor for each technology type was primarily derived from Ram et al. [21]. To estimate the number of jobs gained or lost, the analysis calculated the change in installed capacity for each energy type between 2020 (the base year) and 2040 (the scenario year), representing the difference from the current situation.

The maturity factor, used in the job calculation equation, follows the same methodological assumptions as outlined in [21]. These assumptions were based on OPEX data from Bogdanov et al. [22]. A regional adjustment factor was also applied, recognizing that job creation varies by region due to differences in economic development and labor market structure. In the analysis by Ram et al. [21], this factor ranged from 1 (for the USA) to 7.5 (for South Africa). However, in this study, a regional factor of 1 was adopted to provide a more conservative estimate for Gotland.

Participatory Input and Local Context

A half-day stakeholder workshop in Visby provided critical input into the sustainability assessment. Participants discussed three of the developed scenarios and a reference case, using Gotland’s 2040 vision as a framework. Discussions focused on identifying sustainability risks, opportunities, and trade-offs. Insights from the workshop were integrated with literature reviews and interviews to finalize the set of sustainability indicators. The Logical Framework Approach was used to guide this process, ensuring that sustainability aspects reflected local priorities and practical implementation challenges.

2.2. Heat and Electricity in Gotland Today

Gotland has been divided into six regions: HEM (Hemse), KLN (Klintehamn), LGN (Ljugarn), ROM (Roma), SLT (Slite), and VIS (Visby), as shown in Figure 1. A comprehensive understanding of the current energy system in Gotland is essential to assess the impact and feasibility of the future scenarios. This section provides an overview of the island’s electricity and heating systems, focusing on consumption patterns, production sources, distribution infrastructure, and opportunities for integrating waste heat. More attention is given to the heating sector, which is a central focus of the study, particularly in terms of its contribution to Gotland’s climate and energy goals.

2.2.1. Electricity System

In 2022, Gotland’s total electricity consumption amounted to 884 GWh (Figure 2) [23]. The largest share of electricity demand came from the industrial sector, followed by the service sector and residential buildings, particularly single-family homes. Local electricity production was 452 GWh—just over half of total consumption. Wind power was the dominant source, contributing 421 GWh with an installed capacity of 180 MW. The remaining 430 GWh was imported via two mainland cables, each rated at 160 MW. These cables are expected to reach the end of their technical lifespan by 2035. The electricity system on the island is, therefore, partially self-sufficient, but still highly dependent on mainland imports, especially during periods of low local production or high demand. This interconnection defines the current flexibility of the energy system but also represents a potential vulnerability [24].

2.2.2. District Heating Networks

Gotland has four district heating networks, all operated by Gotlands Energi AB (GEAB), located in Visby, Slite, Klintehamn, and Hemse. The largest and most developed system is in Visby, supplying 210 GWh of heat in 2022. The smaller networks in Slite, Klintehamn, and Hemse supplied 20 GWh, 10 GWh, and 15 GWh, respectively (Figure 3) [25].

These networks are fueled almost entirely by renewable and bio-based sources. In Visby, the primary fuels are forestry residues such as sawdust, branches, and bark, which make up around 40% of the input. Flue gas condensation—an energy recovery process from combustion—contributes approximately 15%. The Slite network is largely supplied by industrial waste heat from Heidelberg Materials Cement. Klintehamn and Hemse rely on field crops and general biomass, respectively. Overall, Gotland’s district heating systems are already fossil-free, relying on a mix of primary biofuels and secondary bio-based waste products.

2.2.3. Heat Demand

Residential, Commercial, and Industrial

Heat demand in Gotland is distributed across residential buildings (including single-family homes and apartment blocks), commercial premises, and industrial facilities. A GIS-based model was used to map and quantify heat density across different zones on the island. This spatial heat demand distribution is essential for evaluating the potential for district heating expansion and integrating waste heat sources (

Table 1. Heat demand for different regions in Gotland.

Area	Heat Demand (GWh/yr)
VIS	368
SLT	139
ROM	78
KLN	82
LGN	91
HEM	163

) [26].

Greenhouses

Greenhouses in Gotland are heated using a combination of biofuels (e.g., pellets and wood chips) and fossil fuels (e.g., diesel and oil), with fossil fuels generally used to cover peak loads. Larger greenhouses operate year-round and require continuous heating, particularly during winter, whereas smaller greenhouses operate seasonally with significantly lower energy demands. The largest greenhouse on the island is located in Slite and is connected to the local district heating system, primarily supplied by industrial waste heat from cement production. This facility—Slite Gurka—is included in the energy system model, with an annual heating demand of approximately 10 GWh.

2.2.4. Waste Heat Sources

Several existing facilities in Gotland can recover waste heat, either already integrated into the energy system or representing future opportunities:

Industrial waste heat: Heidelberg Materials Cement in Slite contributes approximately 16 GWh of waste heat annually to the district heating network. The supply is nearly constant year-round, with a brief shutdown for maintenance.

Data centers: Two data centers in Visby each have cooling requirements of around 1.2 GWh/year. The residual heat from these systems, with supply–return temperatures of 17/25 °C and 15/20 °C, is already partly utilized in the Visby district heating network. While decentralized data centers could provide up to 1.2 GWh/year of residual heat, the temperature levels are relatively low and not directly usable in district heating networks. To make this heat source viable, integration with a heat pump system would be required to elevate the temperature to a usable level. This leads to additional technical and economic considerations that need to be taken into account.

Wastewater treatment: Facilities in Visby, Slite, Roma, Klintehamn, and Hemse offer additional potential for heat recovery. In Visby, some of this heat is already used for district heating.

Grocery stores: Approximately 30 grocery stores on the island generate low-grade waste heat from refrigeration systems, estimated at 70 °C. This residual heat is more abundant in summer and could provide around 15 GWh/year if effectively recovered and integrated.

2.3. Future Plans for Gotland’s Energy System

Gotland’s energy system is on the threshold of a significant transformation, shaped by a range of planned developments in power production, infrastructure, industrial activity, and energy use. These changes are driven by regional and national goals for decarbonization, security of supply, and energy self-sufficiency.

2.3.1. Expansion of Transmission Infrastructure

A critical upgrade involves the installation of two new 220 kV/200 MW AC cables between Gotland and the Swedish mainland, scheduled for completion in 2031. This expansion will enhance the island’s capacity for both electricity imports and exports, reducing vulnerability and facilitating integration of new renewable generation.

2.3.2. Growth in Renewable Generation

Wind and solar power are expected to see substantial increases. Onshore wind capacity is targeted to grow from 180 MW to 380 MW by 2035, while installed solar PV is projected to expand from 3 MW to 30 MW. As of 2022, 20 MW of solar capacity was already installed. Key developments include a planned 3.5 MW solar park by Sunna Group and Roma Grus, and a potential 90 MW solar farm by Fortum.

2.3.3. Offshore Wind and Hydrogen Production

Two large-scale offshore wind farms, Aurora (5.5 GW) and Pleione, are planned by OX2. Aurora, expected to begin operation in 2029, would supply 24 TWh annually and support a 500 MW electrolyzer for hydrogen production, generating around 328 GWh of waste heat. Pleione, entering service by 2033, includes similar hydrogen infrastructure and integration potential. Additional heat (23.6 GWh) will be produced from ammonia nitrate synthesis. This waste heat estimate refers to the high-temperature excess heat generated during the conversion of ammonia to ammonium nitrate, which is commonly used as a fertilizer.

2.3.4. Carbon Capture and Industrial Load Growth

Heidelberg Materials Cement in Slite is preparing to implement CCS technology by 2035, increasing its electricity demand from 300 GWh to 2000 GWh annually. Waste heat quality will decrease due to energy diverted for CO₂ separation, with estimated outputs of 72 MW above 60 °C and 380 MW between 20 and 60 °C.

2.3.5. Emerging Renewable and Industrial Projects

Hydrogen production at a 3 MW electrolyzer in Roma (operational by 2024) will be partially powered by solar energy, contributing 2.4 GWh of waste heat. Methanol production, using solar, thermal, and electrolysis technologies, is also under consideration for the Visby area, with estimated heat availability of 50 GWh annually at 65–125 °C by 2030. Bio-combustion infrastructure by Phoenix Biopower may provide new high-efficiency CHP capacity post-2026. Moreover, large-scale greenhouses (10 ha each) co-located with electrolyzers are planned by Wa3rm, with each requiring ~40 GWh of heat per year at 45–65 °C.

2.3.6. Thermal Storage Integration

Due to geological and regulatory constraints, viable long-term heat storage options include borehole storage and pit storage. Feasibility studies, such as for pit storage in disused limestone quarries near existing district heating networks, are underway. Site selection is heavily influenced by water protection areas and other environmental constraints.

2.3.7. Evolving Heat Demand

Heat demand is expected to decline in existing buildings due to energy efficiency improvements and climate change, with projected reductions per 5-year period of 5–8% from efficiency and 1–2% from warming effects. Conversely, new construction driven by population growth will increase heating needs. Combined, these dynamics are being modeled to project net heat demand changes through 2050.

2.4. Scenarios Description

To explore multiple plausible pathways for Gotland’s transition to a climate-neutral energy system, four future scenarios were developed and analyzed using the TIMES-Gotland model. These scenarios represent different combinations of infrastructure decisions, industrial developments, and degrees of self-sufficiency. While some baseline developments—such as population growth and expansion of renewable energy—are shared across scenarios, each one varies in its industrial activity, energy infrastructure, and policy direction. The purpose of modeling these scenarios is not to predict the future, but to evaluate the implications of strategic choices and to identify trade-offs and synergies in the energy system transition.

All scenarios assume a growing population in Gotland, of course, with different rates depending on industrial development. Renewable energy sources such as onshore wind and solar power are allowed to expand in line with the regional goals outlined in Energipilot Gotland, targeting 380 MW of wind and 30 MW of solar capacity by 2035. In the TIMES model, wind and solar investments are treated as decision variables to allow cost-optimized deployment. In all scenarios except one, the cement industry is assumed to implement carbon capture and storage (CCS) by 2035, requiring increased electricity supply.

The scenarios are (1) carbon capture-no offshore (CC-NOS), (2) no cement (NC), (3) industrial development (ID), and (4) no mainland cable (NM). Below is a description of each scenario.

2.4.1. Carbon Capture-No Offshore (CC-NOS)

The CC-NOS scenario represents the baseline pathway, illustrating a continuation of the existing policies and planned developments (Figure 4a). A new 2 × 220 MW cable restores the connection to the mainland grid by 2031. Industrial operations remain largely unchanged, with no significant additions beyond already approved projects. Where viable, waste heat is recovered and reused, drawing from current and committed initiatives. Heidelberg Materials is projected to implement carbon capture and storage (CCS) by 2035, resulting in an increased electricity demand of up to 250 MW. Population growth aligns with Region Gotland’s projections—rising by 6% between 2022 and 2032, and reaching a cumulative increase of 15% by 2050.

This scenario excludes investments in large-scale offshore wind power. Nonetheless, CCS is integrated into the existing cement facility in Slite by 2030. From that point, electricity demand in Slite grows by 1686 GWh due to industrial expansion. Greenhouse heat consumption remains steady, while buildings show a shift in energy use—heat demand declines overall and electricity usage rises. The island’s power transmission infrastructure includes two separate cables for import and export. Their capacities are 130 MW up to 2030 and expand to 200 MW thereafter.

2.4.2. No Cement Industry (NC)

This scenario mirrors CC-NOS in every aspect except for one critical difference: the complete shutdown of the cement industry. Its purpose is to evaluate how the absence of heavy industry affects Gotland’s energy system and to extrapolate insights to other island regions that lack major industrial facilities. With no industrial operations in Slite, projected population growth slows to 10% between 2022 and 2050.

The cement plant is assumed to be fully decommissioned and dismantled by 2030. Similarly to CC-NOS, this scenario prohibits the development of large-scale offshore wind power. Eliminating cement production reduces electricity demand in Slite by 1686 GWH post-2030. Conversely, greenhouse heat demand in Visby and Slite rises by 40 GWh starting in 2030.

Building energy use trends show a continued decline in heating needs, while electricity consumption increases. The transmission link between Gotland and the mainland is composed of two bidirectional cables, enabling both import and export. Their capacity stands at 130 MW prior to 2030 and increases to 220 MW thereafter.

2.4.3. Industrial Development (ID)

This high-growth scenario is a strong expansion of both renewable energy and new industrial activity (Figure 4b). Two large offshore wind farms are established, and a new mainland cable is completed by 2031 as planned. Transmission from these wind farms connects to the island at two locations: Slite and Ygne (near Visby). Each site becomes a hub for energy-intensive industries, with hydrogen electrolysis plants established at both locations. In Ygne, industrial production includes hydrogen and artificial fertilizer, with large greenhouses co-located to utilize residual heat. A smaller electrolyzer is deployed in Roma, linked to a local solar park. In Visby, methanol production powered by a solar-hybrid park is established, and opportunities for district cooling using excess heat are explored. These developments stimulate job creation and attract new residents, leading to a projected population increase of 20% from 2022 to 2050. Solar power expansion continues beyond the 2035 targets to support growing electricity demand.

This scenario features extensive offshore wind integration and rapid industrial expansion. By 2035, 2000 MW of wind capacity—1000 MW each in Slite and Visby—is in place. CCS is added to the Slite cement plant by 2030. Industrial demand rises sharply, with hydrogen and ammonia production concentrated in Slite, Visby, and Roma. From 2030 onward, industrial electricity use increases substantially, and greenhouse heating demand grows by 40 GWh in both Visby and Slite. Building heat demand declines, while electricity consumption rises.

2.4.4. No Mainland Cable (NM)

This scenario mirrors ID in terms of industrial development and offshore wind deployment but excludes the construction of a new mainland cable (Figure 4c). The purpose is to assess how Gotland could develop a resilient and fossil-free energy system without depending on external grid connections. By removing interconnection with the national grid, the island must balance supply and demand using local resources and infrastructure alone. This tests the limits of local self-sufficiency and emphasizes the importance of storage, sector coupling, and flexible demand solutions.

After 2030, Gotland operates as an independent energy system. By 2035, 2000 MW of offshore wind—1000 MW each in Klintehamn and Slite—is in place. Industrial activity mirrors the ID scenario, with Klintehamn meeting hydrogen and ammonia demands of 541 GWh and 57 GWh. Disconnection drives a sharp rise in industrial electricity use and a 40 GWh increase in greenhouse heat demand in both locations.

3. Results

3.1. Social Sustainability Assessment

The social dimension of the energy transition in Gotland was evaluated through both quantitative estimates (for employment impacts) and qualitative insights gained from stakeholder interviews. Four core aspects were assessed: job creation, social acceptance, attractiveness, and local collaboration. These dimensions are integral to understanding the societal feasibility and implications of various transition scenarios.

3.1.1. Job Creation and Labor Market Effects

The potential for job creation varies significantly across the analyzed scenarios (Figure 5). Projections for 2040 suggest that NM and ID scenarios generate the highest number of jobs. This is largely driven by substantial investments in offshore wind power, which not only increases the installed capacity of the energy system but also catalyzes employment across several segments of the value chain. In contrast, the no cement scenario—characterized by the shutdown of Heidelberg Materials’ cement production in Slite—results in an overall reduction in employment. This is the only scenario with net job losses, primarily affecting male-dominated sectors linked to heavy industry and subcontracting.

Figure 5 illustrates the job creation estimates under both high and low job factor assumptions, highlighting that the inclusion of upstream manufacturing (outside Gotland) in the high scenario results in significantly larger figures—especially for scenarios involving offshore wind deployment. While there are uncertainties embedded in employment factor assumptions, the comparative analysis still provides valuable insights. Offshore wind development consistently appears to be the most robust generator of new employment opportunities. However, the analysis does not determine the geographic location of these jobs; much depends on whether manufacturing, service, and maintenance are localized in Gotland or not.

Stakeholder interviews reinforce these findings and add further points. Respondents differentiate between short-term construction-related jobs—often expected to be filled by temporary external workers—and long-term positions in operations and maintenance, which are more likely to benefit local residents. Concerns were raised about temporary housing pressures, labor market saturation, and gender imbalances in workforce needs.

A frequently mentioned theme was the strain on public sector employment, especially in healthcare, education, and welfare services, which are predominantly female-dominated sectors. The scenarios’ labor demands risk exacerbating this if proactive skills development and recruitment strategies are not implemented. The presence of Uppsala University in Gotland was noted as a potential strategic asset to align educational offerings with emerging labor market needs. Furthermore, emerging sectors linked to green hydrogen—such as fertilizer production, hydrogen-powered transport, and energy storage—were identified as possible areas for new job growth, potentially diversifying the island’s industrial base. Even in the no cement scenario, some interviewees noted potential for job creation in tourism or renewable energy due to the land and energy capacity made available by shutting down cement production.

3.1.2. Social Acceptance

Social acceptance, meaning how the public perceives and reacts to various energy developments, varies significantly across the scenarios. Scenarios involving large offshore wind farms and new industrial establishments often encounter resistance due to concerns about visual impact, lack of local benefit, and fears of Gotland turning into an energy export hub. In interviews and regional consultations, specific concerns were raised about the visual dominance of turbines over the coastal horizon, impacts on migratory birds, and noise effects on marine life.

Similarly, scenarios without offshore wind farms—such as CC-NOS and NM—rely heavily on expanding onshore wind power and large-scale solar parks, which also pose acceptance challenges. For example, Figure 6a illustrates the scale of solar development needed: approximately ten parks the size of the marked black box. Likewise, Figure 6b shows the additional onshore wind capacity required, equivalent to the current setup at Näsudden (highlighted by a red circle), emphasizing the physical footprint involved.

Interviews underline the importance of early and inclusive community engagement in planning to improve acceptance. A general skepticism toward large-scale, top-down solutions is common, particularly regarding grid expansions across private land, which often stirs local opposition. There is also regional concern about who truly benefits economically from offshore wind farms—whether profits stay in Gotland or go to foreign developers. The region’s limited control over offshore wind planning and execution further complicates public trust, as highlighted in consultations for Gotland’s comprehensive plan, where concerns were documented in the meeting minutes. Common points of resistance included perceived threats to nature, inadequate transparency in planning, and a fear of irreversible landscape industrialization. In addition, many voiced strong concerns about both land-based and offshore wind installations. However, offshore wind is sometimes seen more favorably due to its lower impact on the landscape, though some fear it could affect Gotland’s cultural and coastal values.

Tourism stakeholders worry that extensive energy infrastructure could industrialize the island, though the industry lacks a unified stance. On the positive side, scenarios that lead to job creation—particularly during construction—may increase social acceptance, especially among men. Additionally, national surveys suggest women tend to support climate-neutral investments more strongly, hinting that broad-based support could grow if local benefits are clearly communicated and shared.

3.1.3. Attractiveness

Gotland’s attractiveness in terms of living, working, and visiting is shaped by several social and economic conditions. Despite its appeal, challenges such as high housing prices combined with low average incomes—especially among women—undermine its draw. Rising travel costs to and from the island also negatively affect accessibility. Gender differences in daily mobility are evident; men travel longer distances by car, while women depend more on public transport and prefer proximity to childcare and services. The potential loss of the cement industry (no cement scenario) is not expected to drastically affect residents, but could open space for new partnerships and industries.

Region Gotland’s master plan promotes resource-efficient development and population growth through land allocation for wind power, new housing, and infrastructure. The energy transition itself can boost attractiveness by positioning Gotland as a forward-looking, climate-conscious society—similar to developments in Skellefteå. However, this appeal must benefit all parts of the island, not just areas around Visby. Offshore wind farms could reduce visual attractiveness due to their impact on coastal views, but they may simultaneously ensure energy security and job creation, such as through ID with projects like greenhouse cultivation. Still, some fear Gotland may be reduced to an energy hub for Europe, raising concerns especially among tourism stakeholders about view degradation and damage to natural heritage. While a portion of the tourism industry remains cautious, others acknowledge the need for change and support mixed renewable energy developments.

3.1.4. Local Collaborations

Scenarios like no cement could stimulate new local collaborations, particularly in northern Gotland, similar to how new opportunities arose after the defense sector was shut down in Fårösund. Solar energy development could lead to local energy hubs and cooperative projects involving various actors across the island. In the ID scenario, hydrogen production could enable partnerships with entities like Destination Gotland (exploring hydrogen-powered ferries) and agricultural players (e.g., fertilizer production). However, land scarcity near ports limits potential industrial development linked to hydrogen facilities, which need proximity to the sea.

Local entrepreneurship and networks are emphasized as critical for success. Large companies must engage meaningfully with local businesses and communities to avoid resistance and build trust. Early collaboration with educational institutions—ranging from vocational training to university-level programs—is essential to ensure that the local workforce is prepared for upcoming transitions and opportunities.

3.2. Environmental Sustainability Assessment

A comparison of the environmental impacts through LCA of four scenarios (i.e., CC-NOS (base-no offshore wind), ID (industrial development), NM (no mainland cable), and NC (no cement)) is shown in Figure 7. The emissions reported in these figures are the total emissions released during the life cycle of various technologies in various scenarios in different steps: raw material extraction to energy production, heat and electricity generation, hydrogen and ammonia production units, and greenhouses. Overall, the results indicate that the NC scenario and CC-NOS produce less emissions of SO₂, PM, VOCs, NOx, PO4, and Sb than the other scenarios, but have higher land use and need more fossil fuels compared to the rest of the scenarios. Different environmental impacts are presented in the following:

3.2.1. Global Warming Potential (GWP)

The global warming potential (GWP) analysis for the four energy scenarios on the island shows distinct impacts based on the system’s configuration, especially regarding electricity export and offshore wind integration (Figure 7). The CC-NOS scenario, which serves as the baseline without offshore wind power and both electricity import and export, has moderate emissions. The scenario with increased offshore wind and export potential (ID) reduces emissions to some extent, but only modestly compared to CC-NOS. This suggests that while additional offshore wind and export capability are beneficial, they do not lower emissions drastically beyond a certain level due to the complexities of managing higher renewable capacity with export demand.

The NM scenario, which lacks export capability, shows the highest GWP, indicating that the inability to export excess renewable energy leads to higher emissions. In contrast, the NC scenario, characterized by reduced electricity demand, no offshore wind, and the absence of a cement industry, results in the lowest GWP by a significant margin. This shows that demand reduction and removing high-emission industries can dramatically reduce emissions, even without renewables, although this approach might be less practical for an energy-intensive or industrially active island. Overall, export flexibility and demand management play critical roles in achieving lower GWP, with NM surpassing a feasible “red line” threshold due to its limitations in export and emission management.

3.2.2. Acidification Potential (AP)

The life cycle SO₂ emissions of various scenarios are shown in Figure 8. The outcomes display that the NC scenario takes up the most beneficial system from the viewpoint of acidification impact, which produces 3.17 × 10⁵ mole-H+eq. Mol-H⁺ eq (moles of hydrogen ion equivalents) measures acidification potential (e.g., due to SO₂ or NOx emissions).

Cementa, as a cement factory, produces sulfur dioxide and nitrogen oxides primarily due to the high-temperature processes and the composition of raw materials and fuels used. The raw materials, such as limestone and clay, often contain sulfur compounds that, when heated in the kiln, oxidize to form SOx. Additionally, the combustion of sulfur-containing fuels like coal, oil, or pet coke releases more SOx. The extreme heat required to produce clinker, the main component of cement, leads to the formation of NOx by oxidizing nitrogen in the air. These high-temperature reactions are essential for producing cement but result in significant emissions of these acidifying pollutants. Therefore, cutting off Cementa can significantly reduce acidification potential impact, which is formed by release of large quantities of sulfur dioxide, nitrogen oxides, and other acidic pollutants into the atmosphere. These substances can transform into acids upon reacting with atmospheric moisture, leading to acid rain and soil acidification. By halting operations, the emissions of these acid-forming pollutants are minimized, thereby reducing the overall acidification potential and helping to protect ecosystems from acid damage.

The highest value of AP (6.7 × 10⁶ mole H+eq) is relevant to the NM scenario, which produces a huge amount of electricity by offshore wind power units. In fact, electricity generation by offshore wind power units generally has a low acidification impact compared to fossil fuel-based energy sources. However, any higher acidification impact associated with offshore wind power is attributed to the manufacturing, installation, and maintenance processes of the wind turbines. These processes involve activities that release acidifying pollutants, such as the production of steel and concrete, transportation of materials, and operation of construction vessels and machinery, which typically rely on fossil fuels. Moreover, since this scenario lacks a cable connection, there is no electricity export, which results in a higher AP compared to other scenarios that include electricity export.

3.2.3. Eutrophication Potential (EP)

Figure 9 compares the eutrophication potential (EP), measured in kton-PO₄eq, across four scenarios. Kg or kton PO₄³⁻ eq (phosphate equivalents) measures eutrophication potential, indicating the risk of nutrient enrichment in water bodies.

Most scenarios (CC-NOS, ID, and NM) show similar EP levels, around 0.25 kton-PO₄eq, with minor variations, indicating that differences in offshore wind power, electricity export capability, and cable presence have limited impact on eutrophication potential in these configurations. The NC scenario, however, stands out with a significantly lower EP, close to zero, due to its reduced electricity demand and the absence of high-impact industries like cement, which are known contributors to nutrient pollution. This suggests that lowering industrial activity and demand can effectively reduce eutrophication.

3.2.4. Land Use

Figure 10 represents the land use impact for different scenarios. In LCA, the land use impact is often calculated in units of Pt or Person-Year. This unit quantifies the impact of land use changes on human health and well-being over the course of one year for one person. It allows for the evaluation of the potential long-term effects of different land use practices, such as deforestation, agriculture, or urbanization, on human populations.

This can be attributed to the substantial electricity generation from renewable sources, which is primarily exported to the mainland rather than relying on a mixed grid electricity generation approach. Consequently, the need for land in these scenarios is reduced. In contrast, CC-NOS involves importing approximately 1400 GWh of electricity from the mainland, generated from a mix of resources, resulting in a higher land use value. The land use for ID is negative due to the inclusion of 2500 GWh of electricity exports.

3.2.5. Water Consumption

Figure 11 illustrates water consumption measured in million cubic meters across various scenarios. The NC scenario emerges as the most advantageous in terms of water usage, primarily because of its lower electricity demand, resulting in reduced electricity generation needs. Consequently, there is no requirement for biogas turbines, bio-oil engines, or offshore wind power plants in this scenario. However, as electricity generation rises through wind turbines and imported electricity from the mainland, water consumption increases accordingly. ID has the highest water consumption due to its significant electricity exports and moderate imports from the mainland. The imported electricity is sourced from Sweden’s grid mix, which is primarily generated by hydropower plants that require substantial amounts of water.

3.2.6. Resource Use: Minerals and Metals

In addition to increased water usage from the expanded application of wind turbines, there will also be a higher demand for minerals and metals. Figure 12 illustrates the variation in resource use across different scenarios, highlighting this trend. Wind turbines are composed of substantial quantities of steel, copper, aluminum, and rare earth metals, which are essential for components like the tower, generator, and blades. As more wind turbines are deployed to generate electricity, the demand for these raw materials rises, leading to increased extraction and consumption of metals and minerals.

3.3. Overall Assessment

The scenarios examined all aim for a climate-neutral, fossil-free energy system based on renewables, though differences emerge when considering broader sustainability aspects (

Table 2. Weighted assessment of the different scenarios.

		Environmental Aspects					Social Aspects
	GWP	AP	EP	Land Use	Water Use	Resource Use	Job Creation (Quant.)	Job Creation (Qual.)	Social Acceptance	Attractiveness	Local Collaborations
CC-NOS	0	−1	0	0	0	0	0	0	0	0	0
ID	+1	0	−1	+2	+1	−2	+2	+1	0	0	+1
NM	−2	−2	−1	+1	0	0	+2	0	0	0	0
NC	+2	+2	+2	+1	+2	+2	−1	0	0	0	0

). While all contribute to Gotland’s vision of innovative and sustainable growth, they vary in local impacts, risks, and synergies. The base scenario (CC-NOS) faces clear land use challenges that could harm the environment, social acceptance, and tourism unless benefits are clearly shared with the local population. Yet, it offers potential for local collaborations, especially around solar power and education.

The ID scenario—marked by large-scale offshore wind power—has relatively low land use impact and is slightly better for global warming potential, but may increase eutrophication. Its scale raises risks related to low social acceptance, housing pressure, labor shortages, and gender imbalance in job creation. Proper planning, early stakeholder involvement, and attention to working conditions and equality will be key to realizing its benefits. It also presents opportunities to position Gotland as a green energy hub and knowledge center through university and local partnerships.

The no cement scenario shows the most positive environmental outcomes, as removing cement production significantly reduces emissions and improves groundwater availability. However, this comes at the cost of initial job losses and impacts on local businesses, like those dependent on residual heat from Slite. While it avoids some of the social and environmental tensions of energy infrastructure expansion, cement demand would shift emissions elsewhere. Lastly, the no mainland cable scenario is environmentally less favorable due to increased eutrophication and climate impact from a life cycle perspective. Across all scenarios, managing trade-offs—between environmental goals, job creation, equality, and local acceptance—is crucial. Ensuring that developments benefit all parts of Gotland, support local entrepreneurship, and are backed by education and infrastructure will determine the long-term success of the transition.

4. Conclusions

This study demonstrates that Gotland has strong potential to transition to a fossil-free energy system by 2040 through multiple development pathways. By analyzing the interdependencies between the electricity, industrial, and heating sectors as a unified system, the study has identified key synergies and highlighted how strategic integration can optimize energy use and sustainability outcomes. However, the scenarios explored—CC-NOS, ID, NM, and NC—reveal that while climate targets may be met in all cases, the social, economic, and environmental consequences vary significantly.

Electricity demand is projected to more than double in scenarios where the cement industry remains, and increase even more with the addition of new energy-intensive industries. This has significant implications for electricity production, technology choices, and heating system configurations. Scenarios with offshore wind power (ID and NM) enable energy exports and industrial growth but raise concerns over land and sea use, social acceptance, and potential impacts on tourism and housing attractiveness. In contrast, the scenario without cement production (NC) shows the lowest environmental footprint but would lead to major structural changes in Gotland’s local economy and job market.

The heating sector is also shaped by the energy mix and industrial developments, with scenarios increasingly relying on heat pumps and, where available, waste heat. However, unlocking the full potential of waste heat use will require regulatory, technical, and organizational innovation, including long-term investment strategies and stronger collaboration between local stakeholders. A broader sustainability assessment reveals that each scenario involves trade-offs. While some paths support innovation, job creation, and climate goals, they may conflict with land use, biodiversity, or community values. The recent decision by the Swedish government to reject offshore wind projects near Gotland due to defense concerns adds new limitations to the feasibility of certain scenarios, particularly ID.

This study has several limitations that should be considered. First, the analysis is based on scenario-specific assumptions regarding technology availability and industrial development, which could be uncertain. Second, global supply chain emissions and rebound effects outside the island’s borders were excluded from the system boundary. Third, behavioral responses—especially related to public acceptance or investment decisions—were represented qualitatively and may evolve over time. These uncertainties highlight the need for adaptive policy-making and sensitivity analysis in future research.

Scenario-specific recommendations can help support a more grounded transition strategy. In the ID scenario, improving social acceptance may require stronger public consultation processes, community ownership models for offshore wind, and targeted benefit-sharing mechanisms. In CC-NOS and NC, greater focus on local heating innovation—such as decentralized heat pumps and district energy from waste heat—can reduce dependency on new large-scale infrastructure. For NM, energy resilience strategies including local balancing, storage, and smart demand-side management will be essential.

In conclusion, Gotland’s path to a climate-neutral energy system is achievable through various strategies. Yet, success will depend on careful management of environmental and social risks, alignment with local needs and values, and the creation of inclusive, resilient systems. Future planning must go beyond emissions reduction and prioritize long-term resource efficiency, social equity, and regional attractiveness to ensure a just and sustainable transition for the island.