A Block-Free Distributed Ledger for P2P Energy Trading:Case with IOTA?

& #x00A9; 2019, Springer Nature Switzerland AG. Across the world, the organisation and operation of the electricity markets is quickly changing, moving towards decentralised, distributed, renewables-based generation with real-time data exchange-based solutions. In order to support this change, blockchain-based distributed ledgers have been proposed for implementation of peer-to-peer energy trading platform. However, blockchain solutions suffer from scalability problems as well as from delays in transaction confirmation. This paper explores the feasibility of using IOTA’s DAG-based block-free distributed ledger for implementation of energy trading platforms. Our agent-based simulation research demonstrates that an IOTA-like DAG-based solution could overcome the constraints that blockchains face in the energy market. However, to be usable for peer-to-peer energy trading, even DAG-based platforms need to consider specificities of energy trading markets (such as structured trading periods and assured confirmation of transactions for every completed period)

Multi-objective calibration of the land surface scheme TERRA/LM using LITFASS-2003 data

The turbulent sensible and latent heat fluxes simulated in the operational weather forecast model LM have been checked with data from the field experiment LITFASS 2003 (Lindenberg Inhomogeneous Terrain - Fluxes between Atmosphere and Surface: a Long-term Study) using both single site measurements and grid box aggregated fluxes. SCE-UA (single objective) and MOSCEM-UA (multi-objective) approaches were applied to calibrate the land-surface scheme TERRA/LM for 11 single sites and for the aggregated fluxes. A large variation is seen among the parameter sets found by calibration but no typical classification according to vegetation type is obvious. This is attributed to the calibrated parameter sets correcting for model deficiencies and data errors rather than describing the physical characteristics of the measurement site. The measured fluxes were combined into a time series of aggregated fluxes by the tile method. Calibration of TERRA/LM with respect to the averaged fluxes resulted in a range of parameter sets which all simulated the area-averaged fluxes in much better agreement with the observed fluxes than the standard parameter set of the operational model. A modified Nash-Sutcliffe measure as a coincidence criterion fell from 0.3 to a range between 0.15 and 0.28 for the latent heat flux and from 0.43 to between 0.26 and 0.36 for the sensible heat flux when the calibrated parameter sets were used instead of the standard parameters

Power to gas energy storage system for energy self-sufficient smart cities development

The main energy challenge in the smart cities development is the optimization of the energy system to reduce energy cost and greenhouse gas (GHG) emissions. The low feed-in tariff offered by the electricity retailer is another incentive to trade the energy within the project boundaries or neighbouring precincts using the Blockchain peer to peer energy trading. This study develops an energy system model for the RENeW Nexus project as part of smart city development at stage one in the City of Fremantle for a small community (Lot 1819) comprising 36 townhouses and 50 apartments. The system was developed to simulate the optimal Power to Gas (P2G) system for excess renewable energy storage in combination with shared strata battery towards an energy self-sufficiency system. The rooftop area of the townhouses in the developed precinct has been used to generate excess renewable energy from solar photovoltaic (PV) to compensate for less area available on the rooftops of the multi-story apartment's buildings in the presence of a large-scale centralised strata battery. The peer to peer energy trading takes place using Blockchain technology to achieve the energy self-sufficiency goal. The study also identifies the techno-economic viability of P2G system over the large-scale energy storage systems. The model simulation demonstrated that the initial cost of the P2G system is comparably less than the current conventional battery systems

Doppelte Staatsbürgerschaft: Determinanten der deutschen Politik des Staatsangehörigkeitsrechts,

Rieple B, Faist T, Gerdes J. Doppelte Staatsbürgerschaft: Determinanten der deutschen Politik des Staatsangehörigkeitsrechts,. In: Schröter YM, Mengelkamp C, Jäger RS, eds. Doppelte Staatsbürgerschaft - ein gesellschaftlicher Diskurs über Mehrstaatigkeit. Landau: Verlag Empirische Pädagogik; 2005: 97-122