Refine
Year of Publication
- 2016 (32) (remove)
Document Type
- Peer-Reviewed Article (13)
- Conference Object (6)
- Report (6)
- Part of a Book (3)
- Contribution to Periodical (2)
- Working Paper (2)
Language
- English (32) (remove)
Division
- Zukünftige Energie- und Industriesysteme (32) (remove)
Contrary to "static" pathways that are defined once for all, this article deals with the need for policy makers to adopt a dynamic adaptive policy pathway for managing decarbonization over the period of implementation. When choosing a pathway as the most desirable option, it is important to keep in mind that each decarbonization option relies on the implementation of specific policies and instruments. Given structural, effectiveness, and timing uncertainties specific to each policy option, they may fail in delivering the expected outcomes in time. The possibility of diverging from an initial decarbonization trajectory to another one without incurring excessive costs should therefore be a strategic element in the design of an appropriate decarbonization strategy. The article relies on initial experiences in France and Germany on decarbonization planning and implementation to define elements for managing dynamic adjustment issues. Such an adaptive pathway strategy should combine long-lived incentives, like a pre-announced escalating carbon price, to form consistent expectations, as well as adaptive policies to improve overall robustness and resilience. We sketch key elements of a monitoring process based on an ex ante definition of leading indicators that should be assessed regularly and combined with signposts and trigger values at the subsector level.
Distributed cogeneration units are flexible and suited to providing balancing power, thereby contributing to the integration of renewable electricity. Against this background, we analysed the technical potential and ecological impact of CHP (combined heat and power) systems on the German minutes reserve market for 2010, 2020 and 2030. Typical CHP plants (from 1 to 2800 kWel) were evaluated in relation to typical buildings or supply cases in different sectors. The minutes reserve potential was determined by an optimisation model with a temporal resolution of 15 min. The results were scaled up to national level using a scenario analysis for the future development of CHP. Additionally, the extent to which three different flexibility measures (double plant size/fourfold storage volume/emergency cooler) increase the potential provision of balancing power was examined. Key findings demonstrate that distributed CHP could contribute significantly to the provision of minutes reserve in future decades. Flexibility options would further enhance the theoretical potential. The grid-orientated operating mode slightly increases CO2 emissions compared to the heat-orientated mode, but it is still preferable to the separate generation of heat and power. However, the impacts of a flexible mode depend greatly on the application and power-to-heat ratio of the individual CHP system.
Sustainable energy systems
(2016)
Rather than examining aggregate emissions trends, this study delves deep into the dynamics affecting each sector of the EU energy system. It examines the structural changes taking place in power production, transport, buildings and industry, and benchmarks these with the changes required to reach the 2030 and 2050 targets. In so doing it aims to influence both the ambition and direction of future policy decisions, both at Member State and EU level.
In order to assess the adequacy of the EU and its Member States policies with the 2030 and 2050 decarbonisation objectives, this study goes beyond the aggregate GHG emissions or energy use figures and analyse the underlying drivers of emission changes, following a sectoral approach (power generation, buildings, industry, and transport). Historical trends of emission drivers are compared with the required long-term deep decarbonisation pathways, which provide sectoral "benchmarks" or "corridors" against which to analyse the rate and direction of historical change for each Member State and the EU in aggregate. This approach allows the identification of the necessary structural changes in the energy system and policy interventions to reach deep decarbonisation, and therefore the comparison with the current policy programs at European and Member State level.
In this paper a new method for the evaluation and comparison of potential future electricity systems is presented. The German electricity system in the year 2050 is used as an example. Based on a comprehensive scenario analysis defining a corridor for possible shares of fluctuating renewable energy sources (FRES) residual loads are calculated in a unified manner. The share of electricity from PV and wind power plants in Germany in the year 2050 is in a range of 42-122% and the load demand has a bandwidth of around 460-750 TWh. The residual loads are input for an algorithm that defines a supplementary mix of technologies providing flexibility to the system. The overall system layout guarantees the balance of generation and demand at all times. Due to the fact that the same method for residual load calculation and mixture of technologies is applied for all scenarios, a good comparability is guaranteed and we are able to identify key characteristics for future developments. The unique feature of the new algorithms presented here is the very fast calculation for a year-long simulation with hourly or shorter time steps taking into account the state of charge or availability of all storage and flexibility technologies. This allows an analysis of many different scenarios on a macro-economic level, variation of input parameters can easily be done, and extensive sensitivity analysis is possible. Furthermore different shares of FRES, CO2-emission targets, interest rates or social acceptance of certain technologies can be included. The capabilities of the method are demonstrated by an analysis of potential German power system layouts with a base scenario of 90% CO2-reduction target compared to 1990 and by the identification of different options for a power sector with a high degree of decarbonisation. The approach also aims at a very high level of transparency both regarding the algorithms and regarding the input parameters of the different technologies taken into account. Therefore this paper also gives a comprehensive and complete overview on the technology parameters used. The forecast on all technologies for the year 2050 regarding technical and economic parameters was made in a comprehensive consultation process with more than 100 experts representing academia and industry working on all different technologies. An extensive analysis of options for the design of potential German energy supply systems in 2050 based on the presented methodology will be published in a follow-up paper.
Energy intensive industries are one of the fields in which strong increases of energy efficiency and deep decarbonisation strategies are particularly challenging. Although European energy intensive industries have already achieved significant energy and greenhouse gas reductions in the past, much remains to be done to make a significant contribution to achieving European as well as national climate mitigation targets of greenhouse gas emission reductions by -80% or more (compared to the baseline of 1990). North Rhine-Westphalia (NRW) is a European hotspot for coping with this challenge, accommodating more than 10% of the energy intensive industries of the EU28. It is also the first German state to have adopted its own Climate Law, enacting state-wide CO2 emission reductions by 80% until 2050 compared to 1990. The state government initiated the project "Platform Climate Protection and Industry North-Rhine Westphalia" to identify and develop the necessary far-reaching low carbon innovation strategies for energy intensive industries. Heart of the project was a dialogue process, which involved a broad spectrum of stakeholders from steel, chemical, aluminium, cement, glass and paper producing industries. Besides enhancing and broadening the knowledge on high efficiency and low-carbon technologies within industries, the aim was to explore possible pathways and preconditions for the application of these technologies in energy intensive industries as well as to strengthen the motivation of companies for initiatives and investments in technologies with lower CO2 emissions. The results of the dialogue shall provide a basis for a possible low-carbon industry roadmap NRW and may also serve as an example for other industrialized regions in the EU and globally. The paper sketches the structured dialogue process with the stakeholders from companies as well as industrial associations and presents the learnings regarding the engagement of energy intensive industries into ambitious climate policies on a regional level. These include existing limitations as well as chances in the respective sectors on the state level, regarding their economic and technical structures as well as their innovation systems. The findings are based on more than a dozen stakeholder workshops with industry companies and more than 150 individual representatives of NRW's energy intensive industries as well as on background research in the initial phase of the project.
The climate impact of the iron and steel industry can be mitigated through increased energy efficiency, emission efficiency, material efficiency, and product use efficiency resulting in reduced product demand. For achieving ambitious greenhouse gas (GHG) mitigation targets in this sector all measures could become necessary. The current paper focuses on one of those four key measures: emission efficiency via innovative primary steelmaking technologies. After analysing their techno-economical potential until 2100 in part A of this publication, the current research broadens the evaluation scope for the crucial year 2050, based on a Multicriteria-Analysis (MCA). 12 criteria from five different categories ("technology", "society and politics", "economy", "safety and vulnerability" and "ecology") are used to assess the same four future steelmaking technologies in a systematic and holistic way in Germany, as one possible location. The technologies in focus are the blast furnace route (BF-BOF), blast furnace with carbon capture and storage (BF-CCS), hydrogen direct reduction (H-DR), and iron ore electrolysis (EW). These four technologies have been selected, as explained in part A of this paper, because they are the most commonly discussed technological options under discussion by policymakers and the iron and steel industry. The results of the current work should provide decision makers in industry and government with a long-term guidance on technological choices.
In 2050 the MCA shows significantly higher preference scores for the two innovative routes H-DR and EW compared to the blast furnace based routes. The main reasons being higher scores in the economical and environmental criteria. BF-CCS shows its greatest weakness in the social acceptance and the safety and vulnerability criteria. BF-BOF has the lowest economy and ecology score of all assessed routes, which is due to the projected high cost for carbon dioxide emission and increasing prices for fossil fuels. A first indicative trend assessment from today towards 2050 shows that H-DR is the preferred MCA option from today on.
Three exemplary weighting distributions (representing the perspectives of the steel industry, environmental organisations and the government), used to simulate different stakeholder angle of view, don't have a strong influence on the overall evaluation of the steelmaking routes. The results remain very similar, with the highest scores for the innovative routes (H-DR and EW). This leads to the conclusion that EW and in particular H-DR can be identified as the preferred future steelmaking technology across different perspectives.
Specific innovation efforts and dedicated programs are necessary to minimize the time until marketability and to share the development burden. The similarity of the MCA results from different perspectives indicates a great opportunity to reach a political consensus and to work together towards a common future goal. Regarding the pressing time horizon a concentrated engagement for one (or few) technological choices would be highly recommended.
Heat integration and industrial symbiosis have been identified as key strategies to foster energy efficient and low carbon manufacturing industries (see e.g. contribution of Working Group III in IPCC's 5th assessment report). As energy efficiency potentials through horizontal and vertical integration are highly specific by site and technology they are often not explicitly reflected in national energy strategies and GHG emission scenarios. One of the reasons is that the energy models used to formulate such macro-level scenarios lack either the necessary high technical or the spatial micro-level resolution or both. Due to this lack of adequate tools the assumed huge existing potentials for energy efficiency in the energy intensive industry cannot be appropriately appreciated by national or EU level policies. Due to this background our paper describes a recent approach for a combined micro-macro energy model for selected manufacturing industries. It combines national level technical scenario modelling with a micro-modelling approach analogous to total site analysis (TSA), a methodology used by companies to analyse energy integration potentials on the level of production sites. Current spatial structures are reproduced with capacity, technical and energy efficiency data on the level of single facilities (e.g. blast furnaces) using ETS data and other sources. Based on this, both, the investments in specific technologies and in production sites are modelled and the evolvement of future structures of (interconnected) industry sites are explored in scenarios under different conditions and with different objectives (microeconomic vs. energy efficiency optimization). We further present a preliminary scenario that explores the relevance of these potentials and developments for the German steel industry.
In Germany, doubling today's insulation rate of about 1% is an important element for reaching the government's target of reducing the demand for energy in the housing sector by 80% by 2050. A survey among 275 private homeowners was conducted to better understand their insulation activity. The results were incorporated into an agent-based model, which was applied to evaluate new policy options. The results of the survey show that policies should focus on homeowners' wall insulation activity. Homeowners' decision-making processes regarding insulation are largely unaffected by their financial resources, which raises the question of the usefulness of financial incentives. In contrast, non-economic factors were found to have a statistically significant influence: in the year following a house ownership change, a comparatively large number of insulation projects are carried out. The probability of insulating walls can be predicted from knowing the homeowner's age, attitude towards insulation, and the structural condition of the walls. The simulations indicate that information instruments lead to a comparatively small increase in the wall insulation rate, while obligating new homeowners to insulate the walls within the first year after moving in has the potential to increase the total insulation rate by up to 40%.
The increasing rate of renewable energies poses new challenges for industries: the amount of wind and solar energy is by far more subject to fluctuations than that of fossil based energy. Large production facilities from the aluminium, cement, steel or paper industry, however, depend on a highly secure energy supply. To which amount is a limitation of fluctuations possible? This was the key question of the project "Flexibilisation of Industries Enables Sustainable Energy systems", which was realised by the Wuppertal Institute in cooperation with the polymers company Covestro last year. In the final report, authors around project co-ordinator Karin Arnold not only show which technological and economic parameters have been considered, but also present possible business models to promote "flexibility products".
Facing the uncertainty of CO2 storage capacity in China by developing different storage scenarios
(2016)
China is very active in the research and development of CO2 capture and storage technologies (CCS). However, existing estimates for CO2 storage capacity are very uncertain. This uncertainty is due to limited geological knowledge, a lack of large-scale research on CO2 injection, and different assessment approaches and parameter settings. Hence storage scenarios represent a method that can be used by policy makers to demonstrate the range of possible storage capacity developments, to help interpret uncertain results and to identify the limitations of existing assessments. In this paper, three storage scenarios are developed for China by evaluating China-wide studies supplemented with more detailed site- and basin-specific assessments. It is estimated that the greatest storage potential can be found in deep saline aquifers. Oil and gas fields may also be used. Coal seams are only included in the highest storage scenario. In total, the scenarios presented demonstrate that China has an effective storage capacity of between 65 and 1551 Gt of CO2. Furthermore, the authors emphasise a need for action to harmonise storage capacity assessment approaches due to the uncertainties involved in the capacity assessments analysed in this study.
Insulating existing buildings offers great potential for reducing greenhouse gas emissions and meeting Germany's climate protection targets. Previous research suggests that, since homeowners' decision-making processes are inadequately understood as yet, today's incentives aiming at increasing insulation activity lead to unsatisfactory results. We developed an agent-based model to foster the understanding of homeowners' decision-making processes regarding insulation and to explore how situational factors, such as the structural condition of houses and social interaction, influence their insulation activity. Simulation experiments allow us furthermore to study the influence of socio-spatial structures such as residential segregation and population density on the diffusion of renovation behavior among homeowners. Based on the insights gained, we derive recommendations for designing innovative policy instruments. We conclude that the success of particular policy instruments aiming at increasing homeowners' insulation activity in a specific region depends on the socio-spatial structure at hand, and that reducing financial constraints only has a relatively low potential for increasing Germany's insulation rate. Policy instruments should also target the fact that specific renovation occasions are used to undertake additional insulation activities, e.g. by incentivizing lenders and craftsmen to advise homeowners to have insulation installed.
A key factor to energy-efficiency of heating in buildings is the behavior of households, in particular how they ventilate rooms. Energy demand can be reduced by behavioral change; devices can support this by giving feedback to consumers on their behavior. One such feedback device, called the "CO2 meter", shows indoor air-quality in the colors of a traffic light to motivate so called "shock ventilation", which is energy-efficient ventilation behavior. The following effects of the "CO2 meter" are analyzed: (1) the effect of the device on ventilation behavior within households, (2) the diffusion of "CO2 meter" to other households, and (3) the diffusion of changed behavior to households that do not adopt a "CO2 meter". An agent-based model of these processes for the city of Bottrop (Germany) was developed using a variety of data sources. The model shows that the "CO2 meter" would increase adoption of energy-efficient ventilation by c. 12% and reduce heating demand by c. 1% within 15 years. Technology diffusion was found to explain at least c. 54% of the estimated energy savings; behavior diffusion explains up to 46%. These findings indicate that the "CO2 meter" is an interesting low-cost solution to increase the energy-efficiency in residential heating.
Energy systems across the globe are going through a radical transformation as a result of technological and institutional changes, depletion of fossil fuel resources, and climate change. At the local level, increasing distributed energy resources requires that the centralized energy systems be re-organized. In this paper, the concept of Integrated community energy systems (ICESs) is presented as a modern development to re-organize local energy systems to integrate distributed energy resources and engage local communities. Local energy systems such as ICESs not only ensure self-provision of energy but also provide essential system services to the larger energy system. In this regard, a comparison of different energy system integration option is provided. We review the current energy trends and the associated technological, socio-economic, environmental and institutional issues shaping the development of ICESs. These systems can be applied to both developed and developing countries, however, their objectives, business models as well as composition differs. ICESs can be accepted by different actors such as local governments, communities, energy suppliers and system operators as an effective means to achieve sustainability and thereby will have significant roles in future energy systems.
De-industrialization, climate and demographic changes are only a few key words that indicate the challenge of urban development in many industrialized countries for the coming decades. A fundamental transformation of infrastructure and the built environment is expected to adjust to future needs. Numerous concepts of integrating efficiency and renewable energy sources into urban planning were elaborated in recent years. Energy sufficiency in the meaning of voluntary demand reduction of energy intensive goods and services is the third and mostly forgotten pillar of sustainable development. However, organizational and spatial measures are needed to support behavior modification. This paper presents results of a transdisciplinary research design with local stakeholders and scientific experts to develop an understanding of what energy sufficiency might contribute to sustainable urban development. Based on the Multi-Level-Perspective of the transition research approach, it analyzes how stakeholders and experts define energy sufficiency structures for the shrinking district of Vohwinkel (Germany). The paper also shows a compilation and evaluation of measures which facilitate energy sufficient behavior in the fields of space heating and passenger transport on a local level. The methodological concept comprises expert interviews, thought experiments with stakeholders to develop a vision of an "energy sufficient Vohwinkel 2050" as well as a stakeholder workshop to discuss the results. A shrinking population is seen as a chance to actively adapt the built environment to foster energy sufficiency.
Understanding the diversifying role of civil society in Europe's sustainability pathway is a valid proposition both scientifically and socially. Civil society organisations already play a significant role in the reality of cities, what remains to be explored is the question: what is the role of civil society in the future sustainability of European cities? We first examine the novelty of new forms of civil society organization based on a thorough review of recent case studies of civil society initiatives for sustainable transitions across a diversity of European projects and an extensive literature review. We conceptualize a series of roles that civil society plays and the tensions they entail. We argue that, civil society initiatives can pioneer new social relations and practices therefore be an integral part of urban transformations and can fill the void left by a retreating welfare state, thereby safeguarding and servicing social needs but also backing up such a rolling back of the welfare state. It can act as a hidden innovator - contributing to sustainability but remaining disconnected from the wider society. Assuming each of these roles can have unintended effects, such as being proliferated by political agendas, which endanger its role and social mission, and can be peeled off to serve political agendas resulting in its disempowerment and over-exposure. We conclude with a series of implications for future research on the roles of civil society in urban sustainability transitions.
One of the factors decelerating a further diffusion of the carbon capture and storage (CCS) technology is the public's negative perception of early pilot or demonstration activities in Germany as well as in other countries. This study examined the public perception of CCS in more detail by looking into different options within the CCS chain, i.e. for the three elements capture, transport and storage. This was analyzed using an experimental approach, realized in an online survey with a representative German sample of 1830 citizens. Each participant evaluated one of 18 different CCS scenarios created using three types of CO2 source (industry, biomass, coal), two transport options (pipeline vs. no specification), and three storage possibilities (saline aquifer, depleted gas field, enhanced gas recovery (EGR)).
Overall, we found that the ratings of CCS were neutral on average. However, if the CO2 is produced by a biomass power plant or industry, CCS is rated more positively than in a scenario with a coal-fired power plant. The specifications of transport and storage interacted with each other such that scenarios including EGR or a depleted gas field without mentioning a pipeline were evaluated better than storing it in a saline aquifer or a depleted gas field and mentioning a pipeline as means of transport. Exploratory regression analyses indicate the high relevance of the respective CO2 source in general as well as the perceived importance of this source for Germany.
Renewable energy plays a key role in the sustainable pathway towards a low carbon future and, despite new supply capacities, the transformation of the energy system also requires the adoption of a method which allows for the integration of increasing amounts of renewable energy. This requires a transition to more flexible processes at an industrial level and demand side management (DSM) is one possible way of achieving this transition. Currently, increased shares of variable renewable energy can cause the electricity supply to become more volatile and result in changes to the electricity market. In order to develop a new dynamic equilibrium to balance supply and demand, sufficient flexibility in demand is required. As adequate storage systems are not available in the short to medium term, the potential for large electricity consumers to operate flexibly is an attractive, pragmatic and feasible option. Recent studies in Germany suggest that there is significant potential for DSM in so-called "energy-intensive industries". However, the figures (which fall in the approximate range of 1,250-2,750 MW positive and 400-1,300 MW negative shiftable load) should be interpreted with caution. The range of industrial processes considered are diverse and vary from plant to plant, with the result that it is difficult to provide accurate calculations of the accumulated potential for Germany or the EU as a whole. Based on extensive surveys and panel discussions with representatives from energy-intensive industries (aluminum, cement, chemicals, iron & steel, pulp & paper), which together account for approximately one third of the industrial electricity demand in Germany, our paper provides an overview of both the opportunities and the barriers faced by DSM. One of the key findings is the possible loss in energy efficiency due to DSM: in order to decrease or increase production depending on the stability needs of the electricity system, plants and processes may no longer operate at their optimum levels. The effects on downstream production must also be taken into account in order to gain a more complete understanding of the overall effects of industrial DSM.
On behalf of the Port of Rotterdam Authority, the Wuppertal Institute developed three possible pathways for a decarbonised port of Rotterdam until 2050. The port area is home to about 80 per cent of the Netherlands' petrochemical industry and significant power plant capacities. Consequently, the port of Rotterdam has the potential of being an international leader for the global energy transition, playing an important role when it comes to reducing CO2 emissions in order to deliver on the EU's long-term climate goals.
The three decarbonisation scenarios all built on the increasing use of renewables (wind and solar power) and the adoption of the best available technologies (efficiency). The analysis focuses on power plants, refineries and the chemical industry, which together are responsible for more than 90 per cent of the port area's current CO2 emissions.
The decarbonisation scenarios describe how CO2 emissions could be reduced by 75 to 98 per cent in 2050 (compared to 2015). Depending on the scenario, different mitigation strategies are relied upon, including electrification, closure of carbon cycles or carbon capture and storage (CCS). The study includes recommendations for local companies, the Port Authority as well as policy makers. In addition, the study includes a reference scenario, which makes it clear that a "business as usual" mentality will fall well short of contributing adequately to the EU's long-term climate goals.
The need for deep decarbonisation in the energy intensive basic materials industry is increasingly recognised. In light of the vast future potential for renewable electricity the implications of electrifying the production of basic materials in the European Union is explored in a what-if thought-experiment. Production of steel, cement, glass, lime, petrochemicals, chlorine and ammonia required 125 TW-hours of electricity and 851 TW-hours of fossil fuels for energetic purposes and 671 TW-hours of fossil fuels as feedstock in 2010. The resulting carbon dioxide emissions were equivalent to 9% of total greenhouse gas emissions in EU28. A complete shift of the energy demand as well as the resource base of feedstocks to electricity would result in an electricity demand of 1713 TW-hours about 1200 TW-hours of which would be for producing hydrogen and hydrocarbons for feedstock and energy purposes. With increased material efficiency and some share of bio-based materials and biofuels the electricity demand can be much lower. Our analysis suggest that electrification of basic materials production is technically possible but could have major implications on how the industry and the electric systems interact. It also entails substantial changes in relative prices for electricity and hydrocarbon fuels.
Will climate change stay below the 2 degree target in the 21st century on the basis of the COP 21 results? Looking into challenges and opportunities, this paper answers: To stay below the global 2dt is neither a real choice for the world society nor for businesses and civil societies in specific countries. It is a global guideline, scientifically developed for global negotiations, which should be broken down to national interests and actors. Key questions concerning the energy sector from the perspective of national interests are how to create and sustain a momentum for the inevitable energy transition, how to encourage disruptive innovations, avoid lock in effects, enable rapid deployment of energy efficiency and renewable energies etc. Or in other words: how to get to a competitive, economically benign, inclusive, low carbon and risk minimising energy system. With this background the paper argues that "burden sharing" is a misleading perception of strong climate mitigation strategies. It is more realistic to talk about "benefit sharing", using the monetary benefits and co-benefits of climate mitigation (e.g. energy cost savings, revenues from CO2-tax or emission trading systems) to help vulnerable national and international actors to adapt to the unavoidable climate risks. It has to be demonstrated on country level that the technologies and policy mix of strong climate mitigation and risk-minimising actions are indeed "benefit sharing" strategies which should be chosen anyhow, even if there was no climate change. For China and Germany this paper includes basic findings supporting this view.
Carbon markets in a <2 °C world : will there be room for international carbon trading in 2050?
(2016)
This JIKO Policy Paper analyses a series of very ambitious mitigation scenarios and complements this analysis with a review of several sectoral technology roadmaps. The results are quite clear: there is no reason to believe that international carbon trading will become obsolete any time soon. Whether or not international carbon trading is to play a role in international climate protection efforts is in the end not a physical or economic question, but a political one.
The Greens / European Free Alliance Group of the European Parliament contracted Wuppertal Institute in collaboration with Energiaklub to develop scientifically sound, comprehensive, alternative, and sustainable long term energy scenarios for Hungary, which cover potential development paths till 2030 and 2050. The scenarios developed deliver information about the costs and long-term effects of different energy choices for Hungary as well as credible information on potential benefits of greening the energy mix. As a result, the study aims to provide policy makers with better evidence for making informed, prudent and forward-thinking decisions in this field.
This article reviews the literature on the past cost dynamics of various renewable, fossil fuel and nuclear electricity generation technologies. It identifies 10 different factors which have played key roles in influencing past cost developments according to the literature. These 10 factors are: deployment-induced learning, research, development and demonstration (RD&D)-induced learning, knowledge spillovers from other technologies, upsizing, economies of manufacturing scale, economies of project scale, changes in material and labour costs, changes in fuel costs, regulatory changes, and limits to the availability of suitable sites. The article summarises the relevant literature findings for each of these 10 factors and provides an overview indicating which factors have impacted on which generation technologies. The article also discusses the insights gained from the review for a better understanding of possible future cost developments of electricity generation technologies. Finally, future research needs, which may support a better understanding of past and future cost developments, are identified.