Zukünftige Energie- und Industriesysteme
In the energy sector, few topics, if any, are more hyped than hydrogen. Countries develop hydrogen strategies to provide a perspective for hydrogen production and use in order to meet climate-neutrality goals. However, in this topical field the role of water is less accentuated. Hence, in this study, we seek to map the interrelations between the water and wastewater sector on the one hand and the hydrogen sector on the other hand, before reflecting upon our findings in a country case study. We chose the Hashemite Kingdom of Jordan because (i) hydrogen is politically discussed not least due to its high potentials for solar PV, and (ii) Jordan is water stressed - definitely a bad precondition for water-splitting electrolyzers. This research is based on a project called the German-Jordanian Water-Hydrogen-Dialogue (GJWHD), which started with comprehensive desk research mostly to map the intersectoral relations and to scope the situation in Jordan. Then, we carried out two expert workshops in Wuppertal, Germany, and Amman, Jordan, in order to further discuss the nexus by inviting a diverse set of stakeholders. The mapping exercise shows various options for hydrogen production and opportunities for planning hydrogen projects in water-scarce contexts such as Jordan.
Schon seit dem 19. Jahrhundert gilt Wasserstoff als Basis einer nachhaltigen Energiezukunft. Auch wenn sich noch keine kommerzielle Nutzung etabliert hat, sind Wasserstofftechnologien in den vergangenen Jahren deutlich weiterentwickelt worden. In Zusammenarbeit mit dem Wuppertal Institut hat Shell untersucht, welchen Beitrag Wasserstoff zu einer nachhaltigen Energieversorgung - vor allem im Verkehr - künftig leisten kann.
Biogas and bio-methane that are based on energy crops are renewable energy carriers and therefore potentially contribute to climate protection. However, significant greenhouse gas (GHG) emissions resulting from agricultural production processes must be considered. Among those, the production and use of fertilizer, and the resulting leaching of nitrous oxide (N2O), are crucial factors. This article provides an integrated life cycle assessment (LCA) of biogas (i.e. bio-methane that has been upgraded and injected into the natural gas grid), taking into account the processes of fermentation, upgrading and injection to the grid for two different types of biogas plants. The analysis is based on different feedstocks from crop rotation systems for different locations in Germany. A special focus is on the sensitivity of assumptions of nitrous oxide emissions to overall GHG emissions. Much research exists on the measurement or modeling of the actual N2O emissions that result from farming processes. Since there is as yet no precise regional data, most analyses use tier-1 data from the IPCC national GHG inventories as a default. The present article coincides with recent research in indicating that this data varies at the regional level. However, it is not the scope of the article to evaluate the quality of existing data for N2O emissions, but to show the effects of different assumptions on the LCA of GHGs from bio-methane. Thus, a link between the provision of emission data and the practical implementation of biogas technology is provided. The main result is that the supply chain of substrates from agricultural processes appears to contribute the most to the GHG emissions of bio-methane. The "worst case" scenario where 5% of the nitrogen fertilizer used is emitted in form of N2O shows that the GHG mitigation potential of bio-methane versus natural gas is very small, so there is not much margin for error in the plant technology.
Biogas and bio-methane that are based on energy crops are renewable energy carriers and therefore potentially contribute to climate protection. However, significant greenhouse gas emissions resulting from agricultural production processes must be considered, mainly resulting from agricultural production processes, as fertilizer use, pesticide etc.
This paper provides an integrated life cycle assessment (LCA) of biogas (i.e. bio-methane that has been upgraded and injected into the natural gas grid), taking into account the processes of fermentation, upgrading and injection to the grid for two different types of biogas plants thus examining the current state of the art as well as new, large-scale plants, operated by industrial players. Not only technical and engineering aspects are taken into account here, but also the choice of feedstock which plays an important role as to the overall ecological evaluation of bio-methane.
The substrates evaluated in this paper - aside from maize - are rye, sorghum, whole-crop-silage from triticale and barley, and the innovative options of agricultural grass (Landsberger Gemenge, a mixture of hairy vetch (vicia villosa), crimson clover (trifolium incarnátum) and Italian ryegrass (lolium multiflorum)) as well as a combination of maize and sunflower.
Hintergrund: Die Bezugsquellen und Transportwege von fossilem Erdgas werden sich in den kommenden beiden Dekaden diversifizieren. Veränderungen der Lieferstruktur, verbunden mit weiteren Transportentfernungen und dem Neubau von Pipelines sowie der verstärkte Einsatz von verflüssigtem Erdgas (LNG - Liquefied Natural Gas) sind zu erwarten. Entsprechend werden sich auch die vorgelagerten Prozessketten und die damit verknüpften THG-Emissionen verändern. Im Sinne einer korrekten und ganzheitlichen Bilanzierung der Lebenszyklusemissionen und weitgehender Treibhausgasminderungsziele, sind die vorgelagerten Emissionen eine nicht zu vernachlässigende Größe. Gleichzeitig wird Biomethan als Beimischung zum fossilen Erdgas an Bedeutung gewinnen. Obwohl seine Verbrennung als klimaneutral gewertet wird, sind die Prozesse zur Herstellung von Biomethan mit Emissionen verbunden.
Die Treibhausgasemissionen (THG) der Vorketten von in der EU eingesetzten Energieträgern werden in der neuen EU-Kraftstoffqualitätsrichtlinie (vom Dez. 2008) reguliert. Ihre Höhe und ihre Entwicklung wird für die klimapolitischen Diskussionen und politische Entscheidungen somit immer wichtiger.
Ziel: Vor dem Hintergrund der angesprochenen Aspekte sollen die zukünftige Entwicklung der Gasversorgung in Deutschland und die Veränderungen der vorgelagerten THG-Emissionen von Erdgas und Biomethan ermittelt werden. In zwei Szenarien werden die mit der Herstellung und dem Transport von Erdgas und Biomethan verknüpften Emissionen bis zum Jahr 2030 einschließlich des zu erwartenden technischen Optimierungspotenzials bilanziert. Mittels dieser Analyse können Einschätzungen der zukünftigen Emissionspfade und der durchschnittlichen Emissionen (Klimaqualität) des eingesetzten Gases (als Mischung fossiler und biogener Gase einschließlich der damit verbundenen Prozesskettenemissionen) gegeben werden. Diese können als Grundlage für energie- und klimapolitische Entscheidungen dienen.
Ergebnisse und Diskussion: Nach Erläuterung der Prozesskette von Biomethan werden die zu erwartenden technischen Entwicklungen der einzelnen Prozessschritte (Substratbereitstellung, Fermentierung, Aufbereitung, Gärrestnutzung) diskutiert und die Höhe der hiervon zu erwartenden Emissionen bilanziert. Basis sind Ergebnisse der wissenschaftlichen Begleitforschung des Wuppertal Instituts zur Einspeisung von Biomethan ins Erdgasnetz. Dabei gehen wir davon aus, dass die nächste Anlagengeneration "optimierte Technik" das aus heutiger Sicht bestehende Optimierungspotenzial des heutigen Stands der Technik ausschöpfen wird, sodass sich die spezifischen, auf den Heizwert des Biomethan bezogenen, THG-Emissionen der Vorkette von aktuell 27,8 t CO2-Äq/TJ auf 14,8 t CO2-Äq/TJ in 2030 fast halbieren werden.
Die zu erwartenden Emissionen der Erdgasprozesskette wurden in einem Vorgängerartikel bereits im Detail analysiert. Bei der Förderung und der Transportinfrastruktur ist ebenfalls eine Optimierung der Technik zu erwarten. Die dadurch erzielte Verringerung der spezifischen THG-Emissionen kann die aus den künftig längeren Transportstrecken und aufwendigen Produktionsprozessen resultierende Erhöhung ausgleichen.
Abschließend werden zwei Szenarien (Hoch- und Niedrigverbrauch) der künftigen Gasversorgung Deutschlands bis 2030 aufgestellt. Im Hochverbrauchszenario wird damit gerechnet, dass der Gaseinsatz in Deutschland um 17 % steigen wird. Im Niedrigverbrauchszenario wird er dagegen um etwa 17 % sinken. Gleichzeitig wird der Anteil von Biomethan am eingesetzten Gas auf 8 bzw. 12 % ansteigen. Die - direkten und indirekten - Treibhausgasemissionen der Gasnutzung in Deutschland werden im Niedrigverbrauchszenario um 25 %, d. h. überproportional von 215,4 Mio. t CO2-Äq auf 162,4 Mio. t CO2-Äq zurückgehen. Im Hochverbrauchsszenario steigen die Gesamtemissionen leicht um 7 % (auf 230,9 Mio. t CO2-Äq) an.
Schlussfolgerungen: Gasförmige Energieträger werden in den kommenden beiden Dekaden eine zentrale Säule der deutschen Energieversorgung bleiben. Insgesamt zeigt sich, dass die THG-Emissionen der Nutzung von Erdgas v. a. von den Verbrauchsmengen der Gasversorgung abhängig sind. Das heißt, dass sowohl aus klima- als auch aus energiepolitischer Sicht die Steigerung der Energieeffizienz ein zentraler Faktor ist. Daneben bestehen sowohl in der verstärkten Nutzung von Biomethan als auch in der weiteren Investition in emissionsoptimierte Technologien entlang der Vorketten signifikante Emissionsminderungspotenziale. Hierdurch kann die "Klimaqualität", d. h. die spezifische Treibhausgasemissionshöhe über alle Prozessstufen, des eingesetzten Gases deutlich verbessert werden. Die spezifischen Gesamtemissionen pro TJ eingesetzten Gases werden hierdurch um ca. 9 % von heute 63,3 t CO2-Äq pro TJ auf etwa 54,5 t/TJ sinken. Entscheidend ist hierfür der verstärkte Einsatz von Biomethan, dessen Verbrennung aufgrund der biogenen Herkunft des Kohlenstoffs weitgehend klimaneutral ist (im Vergleich zu direkten Emissionen von 56 t CO2/TJ bei der Verbrennung von Erdgas oder 111 t CO2/TJ bei z. B. Braunkohle). Die Vorteile der gasförmigen Energieträger in der Klimaqualität und effizienten Nutzung werden - insbesondere auch in der künftig zu erwartenden Beimischung von Biomethan - auch zukünftig Bestand haben.
Die Bundesregierung verfolgt das ambitionierte Ziel einer Beschleunigung des Ausbaus der erneuerbaren Energien auf 80 % bis 2030 bzw. einer nahezu vollständig erneuerbaren Stromversorgung 2035. Im Zuge der avisierten Elektrifizierung anderer Sektoren wie Wärme und Mobilität im Rahmen der Sektorenkopplung nimmt die Bedeutung des Stromsektors weiter zu. Angesichts der aktuellen geopolitischen Umwälzungen und den sich abzeichnenden Knappheiten für fossiles Gas wird in einer Kurzstudie evaluiert, welchen Platz Biogas in einem langfristig zukunftsfähigen Energiesystem einnehmen kann.
Unvermeidbare Emissionen aus der Abfallbehandlung : Optionen auf dem Weg zur Klimaneutralität
(2022)
Auch die thermische Abfallbehandlung in Deutschland kann zu einem Baustein des klimaneutralen Wirtschaftens werden. Allerdings sind dafür noch verschiedene Voraussetzungen zu schaffen. Technisch sind neben den bereits bekannten weitere innovative Verfahren in der Entwicklung; nicht zu vernachlässigen ist zudem die anspruchsvolle Aufgabe des CO2-Handlings. Hier ist zum einen der Aufbau der benötigten Infrastruktur zu nennen. In Bezug auf die Nutzung des abgetrennten CO2 ist auch die Industrie gefragt, um sektorübergreifende, klimafreundliche Use-Cases und Geschäftsmodelle rund um CCU und die weitmöglichste Schließung von Kohlenstoffkreisläufen zu entwickeln. Entsprechende Regularien und Marktanreize sind politisch zu setzen.
Urban energy systems have been commonly considered to be socio-technical systems within the boundaries of an urban area. However, recent literature challenges this notion in that it urges researchers to look at the wider interactions and influences of urban energy systems wherein the socio-technical sphere is expanded to political, environmental and economic realms as well. In addition to the inter-sectoral linkages, the diverse agents and multilevel governance trends of energy sustainability in the dynamic environment of cities make the urban energy landscape a complex one. There is a strong case then for establishing a new conceptualisation of urban energy systems that builds upon these contemporary understandings of such systems. We argue that the complex systems approach can be suitable for this. In this paper, we propose a pilot framework for understanding urban energy systems using complex systems theory as an integrating plane. We review the multiple streams of urban energy literature to identify the contemporary discussions and construct this framework that can serve as a common ontological understanding for the different scholarships studying urban energy systems. We conclude the paper by highlighting the ways in which the framework can serve some of the relevant communities.
The production of commodities by energy-intensive industry is responsible for 1/3 of annual global greenhouse gas (GHG) emissions. The climate goal of the Paris Agreement, to hold the increase in the global average temperature to well below 2 °C above pre-industrial levels while pursuing efforts to limit the temperature increase to 1.5 °C, requires global GHG emissions reach net-zero and probably negative by 2055-2080. Given the average economic lifetime of industrial facilities is 20 years or more, this indicates all new investment must be net-zero emitting by 2035-2060 or be compensated by negative emissions to guarantee GHG-neutrality. We argue, based on a sample portfolio of emerging and near-commercial technologies for each sector (largely based on zero carbon electricity & heat sources, biomass and carbon capture, and catalogued in an accompanying database), that reducing energy-intensive industrial GHG emissions to Paris Agreement compatible levels may not only be technically possible, but can be achieved with sufficient prioritization and policy effort. We then review policy options to drive innovation and investment in these technologies. From this we synthesize a preliminary integrated strategy for a managed transition with minimum stranded assets, unemployment, and social trauma that recognizes the competitive and globally traded nature of commodity production. The strategy includes: an initial policy commitment followed by a national and sectoral stakeholder driven pathway process to build commitment and identify opportunities based on local zero carbon resources; penetration of near-commercial technologies through increasing valuation of GHG material intensity through GHG pricing or flexible regulations with protection for competitiveness and against carbon leakage; research and demand support for the output of pilot plants, including some combination of guaranteed above-market prices that decline with output and an increasing requirement for low carbon inputs in government procurement; and finally, key supporting institutions.
The war in Ukraine is changing the political landscape at breakneck speed. How should politics and society react to high energy prices and a precarious dependence on fossil fuels imports? Can modern societies get by with much less energy? Energy sufficiency can play an important role in answering these questions. The contributions in this Special topic explore sufficiency as an interdisciplinary research topic for energy modeling, scenarios, and policy.
Im folgenden Beitrag untersuchen wir die Bürgerbeteiligung im Projekt InnovationCity Ruhr - Modellstadt Bottrop. Im Frühjahr 2010 hat der Initiativkreis Ruhr einen Wettbewerb ausgerufen, bei dem die "Klimastadt der Zukunft" gefunden werden sollte. Ausschlaggebend für den Sieg der Ruhrgebietsstadt war das vorgelegte Konzept, welches Gesellschaft, Wirtschaft und Wissenschaft verbindet. Ziel von InnovationCity Ruhr ist es die CO2-Emmissionen in der Stadt bis 2020 zu halbieren und somit eine Vorbildfunktion zur sozial-ökologischen Transformation für das gesamte Ruhrgebiet einzunehmen. Anhand der (Zwischen-) Ergebnisse zweier Untersuchungen (Best 2013; Roose 2014) werden wir veranschaulichen, wie die Bottroper Bevölkerung die Beteiligungsmöglichkeiten im Projekt wahrnimmt. Darüber hinaus decken wir Hemmschwellen auf und geben Empfehlungen zu einer verbesserten Aktivierung der und breiten Beteiligung durch die Bürgerinnen und Bürger.
Sufficiency measures are potentially decisive for the decarbonisation of energy systems but rarely considered in energy policy and modelling. Just as efficiency and renewable energies, the diffusion of demand-side solutions to climate change also relies on policy-making. Our extensive literature review of European and national sufficiency policies fills a gap in existing databases. We present almost 300 policy instruments clustered into relevant categories and publish them as "Energy Sufficiency Policy Database". This paper provides a description of the data clustering, the set-up of the database and an analysis of the policy instruments. A key insight is that sufficiency policy includes much more than bans of products or information tools leaving the responsibility to individuals. It is a comprehensive instrument mix of all policy types, not only enabling sufficiency action, but also reducing currently existing barriers. A policy database can serve as a good starting point for policy recommendations and modelling, further research is needed on barriers and demand-reduction potentials of sufficiency policy instruments.
Prepaid-Strom per Smartphone
(2020)
Prepaid-Stromzähler sind in Deutschland noch selten, bieten jedoch zukünftig einen interessanten Markt. Vor allem kleinere Anbieter, aber auch erste Regionalversorger kombinieren die Megatrends Digitalisierung und Energiewende und kreieren daraus neue Dienstleistungen. Zusammen mit IT-Firmen entwickeln sie daraus neue Geschäftsideen, die auch hinsichtlich sozialer Aspekte hohen Anforderungen genügen. Der Rollout von Smart Metering-Lösungen eröffnet zukünftig noch größere Chancen, durch Echtzeit-Datenerfassung den Energieverbrauch und damit auch Einsparpotenziale transparent zu machen. Hochaufgelöste Daten ermöglichen innovative Dienstleistungen und bringen die Kundenbeziehung auf eine neue Ebene.
Veränderungsprozesse hin zu nachhaltigen Gesellschaften werden bis heute blockiert. Im Text werden diese Blockaden auf der Ebene der Theorie und Konzeption untersucht. Oft soll das Neue der Nachhaltigkeit mit alten Rationalitätsmustern erreicht werden - mit alten Konzepten von Gerechtigkeit, Produktivität, Eigentum. Aber der nachhaltige Gerechtigkeitsanspruch, der Rücksicht auf zukünftige Generationen einfordert, kann mittels der Theorie von John Rawls nicht eingelöst werden. Denn dort besteht unter dem Schleier der Unwissenheit der jeweils Andere nur abstrakt, ohne eigene Stimme. Und der nachhaltige Anspruch des Produktivitätserhalts kann mit dem in den Wirtschaftswissenschaften vorherrschenden Produktivitätskonzept, das auf Adam Smith zurückgeht, ebenfalls nicht eingelöst werden, da es die sorgenden Tätigkeiten von Frauen und die Produktivität der Natur aus dem Ökonomischen ausgrenzt. Und schließlich das Eigentum: In der erstmals von John Locke konzipierten bürgerlichen Eigentumsgesellschaft entstehen Eigentum und Wert nur im unmittelbaren Umwandlungsakt von Natur in Waren. Herrschafts-Eigentum über Ressourcen schließt andere von der Nutzung aus. Die Geschichte einer nachhaltigen gesellschaftlichen Entwicklung bedarf daher ganz anderer, neuer Erzählungen.
The concept of multiple (economic, ecological, social and political) crisis has arisen from recent tumultuous economic events. This paper uses a feminist perspective to present the concept as a crisis of regeneration of both nature and social reproduction. We intend to go beyond multiple crisis using the notion of a new social contract, to overcome this crisis in a transformative way towards sustainability. A feminist analysis of the concept of social contract is founded on the critique of domination and is based on Carole Pateman's, 1988 thesis that the modern social contract is characterized by a "separating inclusion" of women. It also refers to Val Plumwood's critique of the separated and autonomous self, which is part of all classical conceptions of social contract. We argue that overcoming the multiple crisis requires overcoming structures of separation and re-envisioning concepts of the individual, by discussing the German example of a "Social Contract for Sustainability" (2011). If the notion of social contract is to become a catalyst for transformation processes leading to sustainability, it cannot be overarching but has to be developed as a multitude of small new social and local contracts.
Soll der Staat oder der Markt der Hauptakteur im Prozess einer "Großen Transformation" der Gesellschaft sein? Und: Welcher Staat und welcher Markt? Deutlich wird, dass eine Transformation Richtung Nachhaltigkeit nicht gelingen kann, wenn alte Rationalitäts muster - wie die vom starken Staat und vom selbstregulieren den Markt - fortbestehen. Dagegen muss ein demokratischer Prozess stehen, der auf den Fähigkeiten der Bürger(innen) basiert und der emanzipatorische und herrschafts kritische Bewegungen stärkt.
Die Energiewende erfordert eine neue Energiekultur von Politik, Wissenschaft und Gesellschaft. Der Umstieg auf erneuerbare oder regenerative Energien folgt bislang aber vor allem technologischen und ökonomischen Prämissen. Aus nachhaltiger und vorsorgender Perspektive fehlt die Sorge um und für die Regenerationsfähigkeit der Lebensgrundlagen - auch für zukünftige Generationen. Aufgabe von Politik wäre es, Menschen zu einem regenerativen Umgang mit Energie zu befähigen.
Während Fragen der Wertbildung meist als ökonomische behandelt werden, wird in diesem Beitrag der Prozess der Wertbildung politisch und ökonomisch verstanden. Ein Prozess, der von Herrschaft geprägt und doppelseitig ist: Bewertung ist mit Entwertung ebenso verbunden wie die Eingrenzung der Einen mit der Ausgrenzung der Anderen. Diesen Mechanismus nennen wir "Externalisierung als Prinzip". Die politik- und wirtschaftswissenschaftliche Konstruktion des externalisierenden Prinzips und die Herrschaftsformen seiner auch gewaltsamen Durchsetzung werden ideen- und theoriegeschichtlich bearbeitet. Feministische Analysen der klassischen Vertragstheorien und der Politischen Ökonomie zeigen: Die bürgerliche Gesellschaft und ihre Ökonomie werden durch Trennungen geprägt. Das wertvolle Dazugehörige ist angewiesen auf das als wertlos Ausgegrenzte. Es wird deutlich, dass die Geschichte mit der klassischen politischen und ökonomischen Theorie nicht zu Ende ist, sondern dass bis heute herrschaftsförmige Be- und Entwertungen als Mittel zur Krisenbewältigung eingesetzt werden.
Um den Klimawandel begrenzen zu können, wird zunehmend der Einsatz von Direct Air Capture (DAC) zur Erzeugung von Negativemissionen diskutiert. Anhand von Kosten sowie dem Flächen-, Wasser- und Energieverbrauch werden in diesem Artikel mögliche Implementierungspfade der DAC-Technologie, aufbauend auf einem bestehenden Klimaneutralitätsszenario für Deutschland, analysiert. Während die technische Realisierung machbar sein sollte, stellt der hohe Flächen- und Energiebedarf eine kritische Größe dar.
Direct air capture (DAC) combined with subsequent storage (DACCS) is discussed as one promising carbon dioxide removal option. The aim of this paper is to analyse and comparatively classify the resource consumption (land use, renewable energy and water) and costs of possible DAC implementation pathways for Germany. The paths are based on a selected, existing climate neutrality scenario that requires the removal of 20 Mt of carbon dioxide (CO2) per year by DACCS from 2045. The analysis focuses on the so-called "low-temperature" DAC process, which might be more advantageous for Germany than the "high-temperature" one. In four case studies, we examine potential sites in northern, central and southern Germany, thereby using the most suitable renewable energies for electricity and heat generation. We show that the deployment of DAC results in large-scale land use and high energy needs. The land use in the range of 167-353 km2 results mainly from the area required for renewable energy generation. The total electrical energy demand of 14.4 TWh per year, of which 46% is needed to operate heat pumps to supply the heat demand of the DAC process, corresponds to around 1.4% of Germany's envisaged electricity demand in 2045. 20 Mt of water are provided yearly, corresponding to 40% of the city of Cologne's water demand (1.1 million inhabitants). The capture of CO2 (DAC) incurs levelised costs of 125-138 EUR per tonne of CO2, whereby the provision of the required energy via photovoltaics in southern Germany represents the lowest value of the four case studies. This does not include the costs associated with balancing its volatility. Taking into account transporting the CO2 via pipeline to the port of Wilhelmshaven, followed by transporting and sequestering the CO2 in geological storage sites in the Norwegian North Sea (DACCS), the levelised costs increase to 161-176 EUR/tCO2. Due to the longer transport distances from southern and central Germany, a northern German site using wind turbines would be the most favourable.
A cost-minimizing electricity market model was used to explore optimized infrastructures for the integration of renewable energies in interconnected North African power systems until 2030. The results show that the five countries Morocco, Algeria, Tunisia, Libya and Egypt could together achieve significant economic benefits, reaching up to EUR 3.4 billion, if they increase power system integration, build interconnectors and cooperate on joint utilization of their generation assets. Net electricity exports out of North Africa to Europe or Eastern Mediterranean regions, however, were not observed in the regime of integrated electricity markets until 2030, and could only be realized by much higher levels of renewable energy penetration than currently foreseen by North African governments.
Prospects for the integration of power markets and the expansion of renewable energy have recently triggered a number of publications dealing with transformation scenarios of the North African electricity systems. This paper compares five studies using economic electricity supply- and demand models to assess possible development pathways of the North African power systems from today until 2030 and 2050. The analysis shows that distinct modeling methodologies as well as different approaches to scenario design and parameter assumptions can strongly influence the studies' results, leading to very heterogenous projections of North Africa's power generation structures as well as the patterns of electricity exchange with other regions, like Europe. Common findings of the studies are that the surplus costs of capital-intensive renewable energy expansion in North Africa can in most cases be offset by avoided fuel costs and avoided investments in conventional power plants. All studies further agree that increased transnational cooperation, notably in terms of market integration and cross-border power exchanges, can bring about important economic advantages for the North African power sector. Renewable energy expansion could also drive electricity exports to Europe, but in integrated power market schemes, such exports only become viable with a very high share of renewable energy exceeding 60% of the North African power demand.
This paper examines the effects of an increased integration of concentrated solar power (CSP) into the conventional electricity systems of Morocco and Algeria. A cost-minimizing linear optimization tool was used to calculate the best CSP plant configuration for Morocco's coal-dominated power system as well as for Algeria, where flexible gas-fired power plants prevail. The results demonstrate that in both North African countries, storage-based CSP plants offer significant economic advantages over non-storage, low-dispatchable CSP configurations. However, in a generalized renewable integration scenario, where CSP has to compete with other renewable generation technologies, like wind or photovoltaic (PV) power, it was found that the cost advantages of dispatchability only justify CSP investments when a relatively high renewable penetration is targeted in the electricity mix.
The diversification of the national electricity generation mix has risen to the top of Tunisia's energy planning agenda. Presently, natural gas provides 96% of the primary energy for electric power generation, but declining domestic gas reserves and a soaring electricity demand are urgently calling for alternative fuel strategies. Currently discussed diversification options include the introduction of coal and nuclear power plants and/or an increased use of renewable energies. This article presents a methodology to assess different electricity system transformation strategies. By combining an electricity market model with a subsequent multi-criteria decision analysis (MCDA), we evaluate five power mix scenarios regarding power generation costs as well as non-economic dimensions such as energy security, environmental impact and social welfare effects. Based on criteria valuations obtained during consultations with Tunisian stakeholders, a final, best-ranking electricity scenario was selected, consisting of 15% wind, 15% solar and 70% natural gas-generated electricity in the national power mix by 2030.
The global land area required to meet the German consumption of agricultural products for food and non-food use was quantified, and the related greenhouse gas (GHG) emissions, particularly those induced by land-use changes in tropical countries, were estimated. Two comprehensive business-as-usual scenarios describe the development corridor of biomass for non-food use in terms of energetic and non-energetic purposes. In terms of land use, Germany was already a net importer of agricultural land in 2004, and the net additional land required by 2030 is estimated to comprise 2.5–3.4 Mha. This is mainly due to biofuel demand driven by current policy targets. Meeting the required biodiesel import demand would result in an additional GWP of 23–37 Tg of CO2 equivalents through direct and indirect land-use changes. Alternative scenario elements outline the potential options for reducing Germany's land requirement, which reflect future global per capita availability.
This study provides insight into the feasibility of a CO2 trunkline from the Netherlands to the Utsira formation in the Norwegian part of the North Sea, which is a large geological storage reservoir for CO2. The feasibility is investigated in competition with CO2 storage in onshore and near-offshore sinks in the Netherlands. Least-cost modelling with a MARKAL model in combination with ArcGIS was used to assess the cost-effectiveness of the trunkline as part of aDutch greenhouse gas emission reduction strategy for the Dutch electricity sector and CO2 intensive industry. The results show that under the condition that a CO2 permit price increases from €25 per tCO2 in 2010 to €60 per tCO2 in 2030, and remains at this level up to 2050, CO2 emissions in the Netherlands could reduce with 67% in 2050 compared to 1990, and investment in the Utsira trunkline may be cost-effective from 2020–2030 provided that Belgian and German CO2 is transported and stored via the Netherlands as well. In this case, by 2050 more than 2.1 GtCO2 would have been transported from the Netherlands to the Utsira formation. However, if the Utsira trunkline is not used for transportation of CO2 from Belgium and Germany, it may become cost-effective 10 years later, and less than 1.3 GtCO2 from the Netherlands would have been stored in the Utsiraformation by 2050. On the short term, CO2 storage in Dutch fields appears more cost-effective than in the Utsira formation, but as yet there are major uncertainties related to the timing and effective exploitation of the Dutch offshore storage opportunities.
The paper analyzes a Bolivian region for possible cultivation of the oil plant Jatropha curcas for sustainable biodiesel production in order to replace in part Bolivia's diesel imports. The specific site for this study is located in the dry region of Gran Chaco in Santa Cruz. The aim of this work is to analyse the potential of useable land and resources for sustainable biodiesel production from Jatropha without competition with edibles production using economic, environmental and social criteria. In addition the article introduces Jatropha as one of the preferred oil plants for biodiesel production in several countries and indicates its different uses. The recommendation to cultivate Jatropha for biodiesel production is based on an exploration of the possibility of land use in the selected region and the benefits Jatropha production could offer. In this manner a sustainable cultivation of Jatropha in the region of Gran Chaco is recommended to produce biodiesel and to improve some of the environmental problems facing the region.
Sustainability policy in the early 2000s is based on and therefore influenced by scientific literature on "transition". The importance of this link has inspired the authors to explore the structure of cooperating authors and citation networks in the field. In order to understand "transition" literature, we compare it with an alternative term for change, "transformation", which is also used in the context of socio-technical shifts towards sustainability. We expose the different structures of these fields with an overview of keywords, key references, key authors, and the coherence between references and authors. By analysing co-author and citation networks, we find large differences in these groups of documents. The transition literature is characterised by a large network of directly and indirectly cooperating authors with clear clusters; transformation literature contains smaller author networks. Key transition authors are predominantly Dutch. They repeatedly write together and cite each other's work. The transition literature is tightly knit with high degrees of internal references and a clearly distinguishable core. Transformation literature has fewer connections between authors and articles. The connecting articles, each with many global citations, form its basis. This analysis can be used as a step to continue the debate on the role of transition and transformation literature in sustainability and renewable energy policy. The transformation literature teaches us that older streams of thought are still relevant and may be used as "glue" for linking change with respect to sustainable energy to wider developments. Rediscovering existing literature in new combinations may lead to promising new views on sustainable energy.
We present an approach to simulate climate and energy policy for the EU, using a flexible and modular agent-based modelling approach and a toolbox, called the Energy Modelling Laboratory (EMLab). The paper shortly reviews core challenges and approaches for modelling climate and energy policy in light of the energy transition. Afterwards, we present an agent-based model of investment in power generation that has addressed a variety of European energy policy questions. We describe the development of a flexible model core as well as modules on carbon and renewables policies, capacity mechanisms, investment behaviour and representation of intermittent renewables. We present an overview of modelling results, ongoing projects, a case study on current reforms of the EU ETS, and we show their relevance in the EU context.
The Low Carbon Future Cities (LCFC) project aims at facing a three dimensional challenge by developing an integrated city roadmap balancing: low carbon development, gains in resource efficiency and adaptation to climate change. The paper gives an overview of the first outcomes of the analysis of the status quo and assessment of the most likely developments regarding GHG emissions, climate impacts and resource use in Wuxi - the Chinese pilot city for the LCFC project. As a first step, a detailed emission inventory following the IPCC guidelines for Wuxi has been carried out. In a second step, the future development of energy demand and related CO2 emissions in 2050 were simulated in a current policy scenario (CPS). In parallel, selected aspects of material and water flows for the energy and the building sector were analyzed and modeled. In addition, recent and future climate impacts and vulnerability were investigated. Based on these findings, nine key sectors with high relevance to the three dimensions could be identified. Although Wuxi's government has started a path to implement a low carbon plan, the first results show that, for the shift towards a sustainable low carbon development, more ambitious steps need to be taken in order to overcome the challenges faced.
Urbanization and climate change are amongst the greatest challenges of the 21st century. In the "Low Carbon Future Cities" project (LCFC), three important problem dimensions are analysed: current and future GHG emissions and their mitigation (up to 2050); resource use and material flows; and vulnerability to climate change.
The industrial city of Wuxi has been the Chinese pilot city of the project. To establish the pathway for a low carbon future, it is crucial to understand the current situation and possible future developments. The paper presents the key results of the status quo analysis and the future scenario analysis carried out for Wuxi. Two scenarios are outlined. The Current Policy Scenario (CPS) shows the current most likely development in the area of energy demand and GHG emissions until 2050. Whereas the extra low carbon scenario (ELCS) assumes a significantly more ambitious implementation, it combines a market introduction of best available technologies with substantial behavioural change. All scenarios are composed of sub-scenarios for the selected key sectors.
Looking at the per capita emissions in Wuxi, the current levels are already high at around 12 tonnes CO2 per capita compared to Western European cities. Although Wuxi has developed a low carbon plan, the projected results under current policies (CPS) show that the total emissions would increase to 23.6 tonnes CO2 per capita by 2050. If the ELCS pathway was to be adopted, these CO2 emission levels could be reduced to 6.4 tonnes per capita by 2050.
Among the factors that decelerate progress of CCS demonstration and deployment is the lack of public acceptance of local projects in Germany as well as in other countries. The study presented here aims to take the issue of public CCS perceptions further by empirically investigating the relevance of different specifications of the three main steps of the CCS chain, i.e. capture, transport and storage. An experimental approach is chosen and applied in an online survey with a representative sample from Germany with 1830 participants. With regard to possible CO2 sources we varied whether the CO2 of a specific setting is captured i) as part of an energy-intensive industry process (e.g. production of steel or cement), ii) from a power plant running on biomass, or iii) a coal-fired power plant. For transport, half of the settings described made reference to transport of CO2 via pipelines, the other half did not provide information about transport. With regard to storage the setting descriptions i) either explained that CO2 can be stored in saline aquifers, ii) can be used to enhance gas production from an emptying natural gas field or iii) can be stored in a depleted natural gas field. We find that overall the average of the ratings for perception of the settings fall into the neutral part of the answering scale. If the source of CO2 is a coal-fired power plant the setting is perceived less positively than if it includes biomass or industry. A significant interaction effect between transport and storage specifications is observed. This points out that storage in saline aquifers is perceived more negatively than a combination with enhanced gas recovery while storage in a depleted natural gas field is rated less positively if a pipeline is mentioned and more positively if no transport option is mentioned.
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.
"Energiewende", which roughly translates as the transformation of the German energy sector in accordance with the imperatives of climate change, may soon become a byword for the corresponding processes most other developed countries are at various stages of undergoing. Germany's notable progress in this area offers valuable insights that other states can draw on in implementing their own transitions. The German state of North Rhine-Westphalia (NRW) is making its own contribution to achieving the Energiewende's ambitious objectives: in addition to funding an array of "clean and green" projects, the Virtual Institute Power to Gas and Heat was established as a consortium of seven scientific and technical organizations whose aim is to inscribe a future, renewable-based German energy system with adequate flexibility. Thus, it is tasked with conceiving of and evaluating suitable energy path options. This paper outlines one of the most promising of these pathways, which is predicated on the use of electrolytically-produced hydrogen as an energy storage medium, as well as the replacement of hydrocarbon-based fuel for most road vehicles. We describe and evaluate this path and place it in a systemic context, outlining a case study from which other countries and federated jurisdictions therein may draw inspiration.
Water and energy are two pivotal areas for future sustainable development, with complex linkages existing between the two sectors. These linkages require special attention in the context of the energy transition. Against this background, this paper analyses the role of water availability in the development of solar thermal and photovoltaic power plants for the case of the Draa Valley in southern Morocco. Located in a semi-arid to arid mountainous area, the Drâa Valley faces high water stress - a situation expected to worsen due to climate change. At the same time, the region has one of the greatest potentials for solar energy in the world. To examine whether limited water availability could accelerate or delay the implementation of solar thermal and photovoltaic power plants, this paper compares regional water availability and demand in the Draa Valley for different scenarios, paying particular attention to potential socio-economic development pathways. The Water Evaluation and Planning System software is applied to allocate the water resources in the study region. The water supply is modelled under the Representative Concentration Pathway 8.5 climate scenario, while the water demand for the Drâa Valley is modelled for a combination of three socio-economic and two energy scenarios. The climate scenario describes a significant decrease in water availability by 2050, while the socio-economic and energy scenarios show an increase in water demand. The results demonstrate that during a sequence of dry years the reservoirs water availability is reduced and shortages in water supply can result in high levels of unmet demand. If this situation occurs, oasis farming, water for drinking and energy production could compete directly with each other for water resources. The energy scenarios indicate that the use of dry cooling technologies in concentrated solar power and photovoltaic hybrid systems could be one option for reducing competition for the scarce water resources in the region. However, given that energy generation accounts for only a small share of the regional water demand, the results also suggest that socio-economic demand reduction, especially in the agricultural sector, for example by reducing the cultivated area, will most likely become necessary.
Green hydrogen and synthetic fuels are increasingly recognized as a key strategic element for the progress of the global energy transition. The Middle East and North Africa (MENA) region, with its large wind and solar potential, is well positioned to generate renewable energy at low cost for the production of green hydrogen and synthetic fuels, and is therefore considered as a potential future producer and exporter. Yet, while solar and wind energy potentials are essential, other factors are expected to play an equally important role for the development of green hydrogen and synthetic fuels (export) sectors. This includes, in particular, adequate industrial capacities and infrastructures. These preconditions vary from country to country, and while they have been often mentioned in the discussion on green hydrogen exports, they have only been examined to a limited extent. This paper employs a case study approach to assess the existing infrastructural and industrial conditions in Jordan, Morocco, and Oman for the development of a green hydrogen and downstream synthetic fuel (export) sector.
This theory note develops a theoretical approach which integrates the negative spillovers that international institutions often impose on each other into our thinking about their normative legitimacy. Our approach draws on the political philosophy of Rainer Forst which revolves around the right to justification. It suggests that regime complexes facilitate the breakup of institution-specific orders of justification by prompting invested actors to justify negative spillovers vis-a-vis each other. Thus, regime complexes enable more encompassing justifications of negative spillovers than stand-alone international institutions. Against this backdrop, we submit that the proliferation of regime complexes represents normative progress in global governance.
Die Diskussion um die Gestaltung der Energiewende dreht sich in der politischen und gesellschaftlichen Debatte heute maßgeblich um die Stromversorgung der Zukunft. Ausstieg aus der Kohleverstromung und Ausbau bzw. Optimierung von Stromtransport- und verteilnetz sind nur zwei Beispiele dafür. Zu wenig Beachtung wird dagegen den Gasinfrastrukturen geschenkt und dabei insbesondere den Gas(import-)infrastrukturen, die mit Blick auf die Energiewende eine signifikante Rolle spielen (können).
Given large potentials of the MENA region for renewable energy production, transitions towards renewables-based energy systems seem a promising way for meeting growing energy demand while contributing to greenhouse gas emissions reductions according to the Paris Agreement at the same time. Supporting and steering transitions to a low-carbon energy system require a clear understanding of socio-technical interdependencies in the energy system as well as of the principle dynamics of system innovations. For facilitating such understanding, a phase model for renewables-based energy transitions in MENA countries, which structures the transition process over time through the differentiation of a set of sub-sequent distinct phases, is developed in this article. The phase model builds on a phase model depicting the German energy transition, which was complemented by insights about transition governance and adapted to reflect characteristics of the MENA region. The resulting model includes four phases ("Take-off renewables", "System integration", "Power to fuel/gases”, "Towards 100% renewables”), each of which is characterized by a different cluster of innovations. These innovations enter the system via three stages of development which describe different levels of maturity and market penetration, and which require appropriate governance. The phase model has the potential to support strategy development and governance of energy transitions in MENA countries in two complementary ways: it provides an overview of techno-economic developments as orienting guidelines for decision-makers, and it adds some guidance as to which governance approaches are suitable for supporting those developments.
Obwohl viele der aktuellen Herausforderungen im Bereich der Energieversorgung eine internationale Dimension haben bzw. nur international gelöst werden können, ist die internationale Energiepolitik bis heute ein weitgehend ungesteuerter Politikbereich. Im letzten Jahrzehnt entwickelten sich zwar neue globale Kooperationsstrukturen und Initiativen, der Weg zu einer multilateralen, globalen Governance-Struktur, die zentrale Impulse für die gemeinsame Etablierung international geltender Normen und Regeln geben könnte, ist aber noch weit. Der Artikel führt in die aktuellen Entwicklungen ein und diskutiert die verbleibenden Herausforderungen.
At current primary steel production levels, the iron and steel industry will fail to meet the 80% emission reduction target without introduction of breakthrough technologies (Wörtler et al., 2013: 19). The current research analyses the technical and economical long-term potential of innovative primary steel production technologies in Germany throughout 2100. Techno-economic models are used to simulate three innovative ore-based steelmaking routes verses the reference blast furnace route (BF-BOF). The innovative routes in focus are blast furnace with CCS (BF-CCS), hydrogen direct reduction (H-DR), and iron ore electrolysis (EW). Energy and mass flows for the production of one tonne of crude steel (CS) are combined with hypothetical price, cost, and revenue data to evaluate the production routes economically, technically, and environmentally. This is a purely theoretical analysis and hence further external factors that may influence practical implementation or profitability are not considered.
Different future developments are considered by using three scenarios, representing an ambitious, a moderate, and a conservative transformation of the German energy sector. In general, looking into the future bares various uncertainties which should be reflected in a suitable manner.
According to the present scenario analysis, chances are that with rising prices for coal and CO2 allowances BF-BOF and even BF-CCS become unprofitable by mid-century. With a high share of renewable energy sources and high prices for CO2 allowances, H-DR and EW become economically attractive in the second half of the current century, when BF-based routes are long unprofitable. Energy and raw material efficiency is significantly higher for H-DR and EW and furthermore, the 80% reduction target by 2050 can be achieved in the ambitious scenario. However, high investment costs and high dependency on electricity prices prohibit a profitable implementation before 2030–2040 without further subsidies. EW is the most energy and resource efficient production route. Since continuous electricity is needed for the continuous operation, the electricity costs are 20–40% higher than for H-DR (with high-capacity hydrogen storage units). Even though hydrogen production implies efficiency losses compared to the EW route, the decoupling of hydrogen production from continuous operation of the steel plant through hydrogen storage offers the opportunity to use cheap excess renewable electricity. This makes the H-DR economically and environmentally the most attractive route and provides a crucial contribution to stabilize the grid and to store excess energy in a 100% renewable energy system.
Based on different current long-term energy scenarios the paper discusses the future perspectives of hydrogen in the German energy system as a representative example for the development of sustainable energy systems. The scenario analysis offers varying outlines of the future energy system that determine the possible role of hydrogen. The paper discusses the possibilities of expanding the share of renewable energy and the resulting prospects for establishing clean hydrogen production from renewable energy sources. Emphasis is given to the questions of an ecologically efficient allocation of limited renewable energy resources that can only be assessed from asystems analysis perspective. Findings from recent studies for Germany reveal a strong competition between the direct input into the electricity system and an indirect use as fuel in the transport sector. Moreover, the analysis underlines the paramount importance of reducing energy demand as the inevitable prerequisite for any renewable energy system.
Die Landesregierung in NRW hat am 14.4.2015 den in einem aufwändigen Stakeholderprozess erstellten Klimaschutzplan vorgestellt. Eines der Ziele war, die Klimaschutzpolitik als langfristige Strukturpolitik zu implementieren und entsprechende Prozesse in die Breite der Gesellschaft zu tragen. Weitere Bundesländer und der Bund selbst haben inzwischen ähnliche Prozesse eingeleitet. In zahlreichen anderen Ländern gibt es Beschlüsse, die in diese Richtung gehen. Eine Übersicht über den Prozess der Planerstellung in NRW und über den Stand der Diskussion in Deutschland verdeutlicht, wie Klimaschutzpläne durch partizipatorische Elemente in der Erstellungsphase mehr Akzeptanz erfahren können.
Staatliche Regulierung ist verpönt. Häufig läuft es dann auf den Appell hinaus: Jeder einzelne Bürger habe es selbst in der Hand. Doch die Alltagsroutinen sind in der Regel mächtiger als das Umweltbewusstsein. Beim Marmor für das Badezimmer spielen Amortisationszeiten keine Rolle. Die solare Warmwasseranlage ist dagegen oftmals "zu teuer". Gesetzliche Standards hingegen verselbstständigen Energieeffizienz und den Ausbau erneuerbarer Energien. Sie machen "Öko zur Routine". Dieser Artikel beschreibt die Notwendigkeit für das Schaffen neuer Routinen und zeigt wie dies durch Standards, Limits und faire Umsetzungsbedingungen sowie attraktive Alternativangebote zum gegenwärtigen, häufig nicht nachhaltigen Verhalten auch möglich ist.
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.
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 buildings sector accounts for more than 30% of global greenhouse gas emissions. Despite the well-known economic viability of many energy-efficient renovation measures which offer great potential for reducing greenhouse gas emissions and meeting climate protection targets, there is a relatively low level of implementation. We performed a citation network analysis in order to identify papers at the research front and intellectual base on energy-efficient renovation in four areas: technical options, understanding decisions, incentive instruments, and models and simulation. The literature was reviewed in order to understand what is needed to sufficiently increase the number of domestic energy-efficient renovations and to identify potential research gaps. Our findings show that the literature on energy-efficient renovation gained considerable momentum in the last decade, but lacks a deep understanding of the uncertainties surrounding economic aspects and non-economic factors driving renovation decisions of homeowners. The analysis indicates that the (socio-economic) energy saving potential and profitability of energy-efficient renovation measures is lower than generally expected. It is suggested that this can be accounted for by the failure to understand and consider the underpinning influences of energy-consuming behaviour in calculations. Homeowners׳ decisions to renovate are shaped by an alliance of economic and non-economic goals. Therefore, existing incentives, typically targeting the economic viability of measures, have brought little success. A deeper understanding of the decisions of homeowners is needed and we suggest that a simulation model which maps the decision-making processes of homeowners may result in refining existing instruments or developing new innovative mechanisms to tackle the situation.
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.
Combined heat and power (CHP) production in buildings is one of the mitigation options available for achieving a considerable decrease in GHG emissions. Micro-CHP (mCHP) fuel cells are capable of cogenerating electricity and heat very efficiently on a decentralised basis. Although they offer clear environmental benefits and have the potential to create a systemic change in energy provision, the diffusion of mCHP fuel cells is rather slow. There are numerous potential drivers for the successful diffusion of fuel cell cogeneration units, but key economic actors are often unaware of them. This paper presents the results of a comprehensive analysis of barriers, drivers and business opportunities surrounding micro-CHP fuel-cell units (up to 5 kWel) in the German building market. Business opportunities have been identified based not only on quantitative data for drivers and barriers, but also on discussions with relevant stakeholders such as housing associations, which are key institutional demand-side actors. These business opportunities include fuel cell contracting as well as the development of a large lighthouse project to demonstrate the climate-neutral, efficient use of fuel cells in the residential building sector. The next step could involve the examination and development of more detailed options and business models. The approach and methods used in the survey may be applied on a larger scale and in other sectors.
Model-based scenario analyses of future energy systems often come to deviating results and conclusions when different models are used. This may be caused by heterogeneous input data and by inherent differences in model formulations. The representation of technologies for the conversion, storage, use, and transport of energy is usually stylized in comprehensive system models in order to limit the size of the mathematical problem, and may substantially differ between models. This paper presents a systematic comparison of nine power sector models with sector coupling. We analyze the impact of differences in the representation of technologies, optimization approaches, and further model features on model outcomes. The comparison uses fully harmonized input data and highly simplified system configurations to isolate and quantify model-specific effects. We identify structural differences in terms of the optimization approach between the models. Furthermore, we find substantial differences in technology modeling primarily for battery electric vehicles, reservoir hydro power, power transmission, and demand response. These depend largely on the specific focus of the models. In model analyses where these technologies are a relevant factor, it is therefore important to be aware of potential effects of the chosen modeling approach. For the detailed analysis of the effect of individual differences in technology modeling and model features, the chosen approach of highly simplified test cases is suitable, as it allows to isolate the effects of model-specific differences on results. However, it strongly limits the model's degrees of freedom, which reduces its suitability for the evaluation of fundamentally different modeling approaches.