Effects of the tenants electricity law on energy system layout and landlord-tenant relationship in a multi-family building in Germany

Multi-family buildings (MFB) accommodate 53% of the German apartment stock. Although PV-systems on single-family buildings are widely implemented, the PV-potential on MFBs has barely been touched. Therefore, the German government introduced the Mieterstromgesetz, the tenants electricity law (TEL), in 2016. This law exempts electricity directly produced and consumed in a building from certain charges and taxes. Within the TEL framework, the landlord acts as the local electricity provider and can profit from selling electricity to the tenants and tenants can save electricity costs. This paper analyses the techno-economic effects of the TEL on the energy system layout of a MFB in Germany. Furthermore, it gives implications on how the TEL affects the tenant-landlord relationship. In this analyses, a MILP model is used to maximize the net present value (NPV) and determines the optimal layout and dispatch of the energy system. The model can choose to invest in PV, CHP and a battery storage system. Additionally, one to six electric vehicles (EVs) are integrated into the model. The novelty of this paper is the model-based analysis of the German Mieterstromgesetz considering EVs. The results show that the combination of PV and CHP is the most profitable system layout with NPVs up to 31.9ke. An optimized charging strategy increases the self-consumption rate and the NPV substantially compared to a fast-charging-strategy. Thus, the TEL can create a symbiotic relationship between landlords and tenants

Urban Resource Assessment, Management, and Planning Tools for Land, Ecosystems, Urban Climate, Water, and Materials - A Review

Increasing awareness of global and local climate change and the limited resources of land, surface, water, raw materials, urban green spaces, and biodiversity alter the exigencies of urban development. Already perceivable local climate changes such as heavy rains, droughts, and urban heat islands urge planners to take action. Particularly in densely populated areas, conflicting interests are pre-programmed, and decision making has to include multiple impacts, mutual competition, and interaction with respect to investments into provisioning services. Urban planners and municipal enterprises increasingly work with digital tools for urban planning and management to improve the processes of identifying social or urbanistic problems and redevelopment strategies. For this, they use 2D/3D city models, land survey registers, land use and re-/development plans or other official data. Moreover, they increasingly request data-based planning tools to identify and face said challenges and to assess potential interventions holistically. Thus, this contribution provides a review of 51 current tools. Simple informational tools, such as visualizations or GIS viewers, are widely available. However, databases and tools for explicit and data-based urban resource management are sparse. Only a few focus on integrated assessment, decision, and planning support with respect to impact and cost assessments, real-time dashboards, forecasts, scenario analyses, and comparisons of alternative options

Optimal system design for energy communities in multi-family buildings : the case of the German Tenant Electricity Law

Funding Information: The second author (MK) appreciates the support of the Helmholtz Association under the Joint Initiative Energy Systems Integration (funding reference: ZT-0002 ). The fourth author (FS) kindly acknowledges the financial support of the European Union’s Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement no. 713683 (COFUNDfellowsDTU). The fifth author (RM) gratefully acknowledges the support of the European Commission’s DG ENER for project ENER/C3/2019-487 . Finally, the authors are grateful for the helpful comments of two anonymous reviewers during earlier revisions of this manuscript. The usual disclaimer applies. Funding Information: The second author (MK) appreciates the support of the Helmholtz Association under the Joint Initiative Energy Systems Integration (funding reference: ZT-0002). The fourth author (FS) kindly acknowledges the financial support of the European Union's Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement no. 713683 (COFUNDfellowsDTU). The fifth author (RM) gratefully acknowledges the support of the European Commission's DG ENER for project ENER/C3/2019-487. Finally, the authors are grateful for the helpful comments of two anonymous reviewers during earlier revisions of this manuscript. The usual disclaimer applies. Publisher Copyright: © 2021 Elsevier LtdPeer reviewedPostprin

Namares—A Surface Inventory and Intervention Assessment Model for Urban Resource Management

Densely built-up areas are challenged by reduced biodiversity, high volumes of runoff water, reduced evaporation, and heat accumulation. Such phenomena are associated with imperviousness and low, unsustainable utilisation of land and exterior building surfaces. Local authorities have multiple objectives when (re-)developing future-proof districts. Hence, exploiting local potentials to mitigate adverse anthropogenic effects and managing the resource of urban land/surfaces have become key priorities. Accordingly, a five-level hierarchy for a land-sensitive urban development strategy was derived. To support the operationalisation of the hierarchy, we present the model Namares, a highly resolved GIS-based approach to enable spatially explicit identification and techno-economic and environmental assessment of intervention measures for advantageous utilisation of available surfaces per land parcel. It uses existing data and covers the management of economic, natural, and technical resources. Nine intervention measures are implemented to identify potentials, estimate investments and annual costs, and assess the appeal of existing subsidies. The approach was applied to a case study redevelopment area in a large city in Germany. The results provide spatially explicit information on greening potentials, estimated investments, subsidy demand, and other quantified benefits. The case study results show the limited potential for additional unsealing of impervious surfaces by transforming ca. 10% of sealed ground surface area into new urban gardens. At the same time, up to 47% of roof and 30% of facade surfaces could be utilised for greening and energy harvesting. The approach enables a comprehensive localisation and quantitative assessment of intervention potentials to enhance decision support in land-sensitive urban development strategies

Historic drivers of onshore wind power and inevitable future trade-offs

The required acceleration of onshore wind deployment requires the consideration of both economic and social criteria. With a spatially explicit analysis of the validated European turbine stock, we show that historical siting focused on cost-effectiveness of turbines and minimization of local disamenities, resulting in substantial regional inequalities. A multi-criteria turbine allocation approach demonstrates in 180 different scenarios that strong trade-offs have to be made in the future expansion by 2050. The sites of additional onshore wind turbines can be associated with up to 43% lower costs on average, up to 42% higher regional equality, or up to 93% less affected population than at existing turbine locations. Depending on the capacity generation target, repowering decisions and spatial scale for siting, the mean costs increase by at least 18% if the affected population is minimized – even more so if regional equality is maximized. Meaningful regulations that compensate the affected regions for neglecting one of the criteria are urgently needed

institutional innovation from the bottom up?

A sustainable economy fulfills societal needs in a fundamentally different way to the current economic system. Improvements to the efficiency of existing technologies or practices appear insufficient for achieving sustainable development within the planetary boundaries. Disruptive, systemic and transformational changes appear necessary in order to replace existing technologies and practices to establish a sustainable economy. Such innovations often start out in niches; however, the scaling up and the ultimate replacement of current socio-technical systems requires governance to allow for the coordination of actors, the reorganization of socio-technical systems and the mobilization and allocation of resources. As governmental institutions are part of the current (non-sustainable) systems and thereby fail to provide coherent, integrated and transformative governance, we explore whether institutional innovation from non-state actors can step in to provide governance of transformation processes. Based on explorative qualitative case studies of networks in the food sector, city planning and reporting tools, we analyze the potential of bottom-up institutional innovations to coordinate actors in transformation processes

A survey of private landlords in Karlsruhe and their perception of deep energy retrofit

Energy use related to buildings accounts for 35.3% of Germany\u27s final energy consumption and nearly a third of greenhouse gas emissions. Thus, deep energy retrofit (DER) has a substantial role in the German energy efficiency strategy. Although many DER measures are economically viable, the pace of DER is below expectations and target value. A few studies investigated this phenomenon and conducted surveys mostly among owner-occupiers. However, 54% of the 40.5 million apartments in Germany are rented and a total of 15 million are let by private (not professional) landlords. Therefore, this investigation focuses on private landlords to find out what drives or constrains them to do deep energy retrofitting. A survey was conducted in a quarter of Karlsruhe, a large city in Germany with an above-average demand-driven real estate market. In this quarter, 83.2% or 8464 apartments are rented. 85 private landlords who own 10% of the rented residential buildings in the quarter responded and gave insight into their perception of DER. The results show that the buildings of the respondents originate from a construction period with large saving potential. Main strategies for investments in DERs are conservation of economic value of the property and the compliance with legal requirements. The main trigger is required maintenance. Despite an eco-friendly attitude, ecological criteria have a minor part in the DER decision. Finally, policy recommendations are made