220 research outputs found
Interaction of DSO and local energy systems through network tariffs
One crucial factor that influences distributed energy resource investments and operation is the grid tariffs. If the price signal passed on to the consumer is not representative of the actual impact of the decentralized decisions on the power system, we may get inefficiencies. The main problem considered in this research is the interaction of a network operator and consumers to study how grid tariffs should be designed to facilitate favorable decentralized decisions. An equilibrium model based on tariffs is developed and benchmarked against a system optimization to study the effect of capacity-based and volumetric grid tariffs when the grid costs are a function of the decentralized decisions. The results show that both a volumetric and capacity-based tariff scheme provides a suboptimal outcome compared to the system optimal solution. Suboptimal decentralized decisions in the perspective of the overall power system is a result of the tariff schemes not being able to represent the actual network costs. Based on the findings, more innovative tariff schemes or related market mechanisms are needed to facilitate decentralized decisions that are aligned with the costs and benefits for the overall power system.Interaction of DSO and local energy systems through network tariffsacceptedVersio
Teachersâ views on collaborating in multi-campus course cluster for engineering students
At a European multi-campus university, parallel study programmes offered at every campus (e.g. engineering studies) and appurtenant courses are coordinated, to ensure similar quality and systematic development. In this paper, we present a case from such a multi-campus course, consisting of a cluster of basic courses in physics and chemistry for first-year engineering students. These courses are coordinated through identical syllabus and assessment practice but are taught locally at each campus. The authors had noted some frustration among the teachers involved in these courses, and were interested to investigate the reasons for this frustration, and ultimately to inform the development of these multi-campus courses. This project emerged from a realisation that literature on multi-campus courses is often associated with distance learning, while in this case, the actual teaching is provided locally. Concepts associated with teacher collaboration, such as collaborative culture versus contrived collegiality, collective versus fragmented collaboration, and depth of collaboration seem like a viable way forward in understanding the dynamics between teachers in a context like this. In this paper, we present early results from this ongoing project, which include interviews of teachers involved in these physics/chemistry courses. Preliminary results from these interviews suggest that the expressed frustrations stem from contrived collegiality. Although the teachers experience sufficient freedom in terms of choosing their own teaching methods, several teachers raise concerns about the lack of common aims for this course cluster, which reduces collaboration to coordination of mere practical tasks
Impact of Grid Tariffs Design on the Zero Emission Neighborhoods Energy System Investments
This paper investigates the relationship between grid tariffs and investment
in Zero Emission Neighborhoods (ZEN) energy system, and how the grid exchanges
are affected. Different grid tariffs (energy based, time of use (ToU),
subscribed capacity and dynamic) are implemented in an optimization model that
minimizes the cost of investing and operating a ZEN during its lifetime. The
analysis is conducted in two cases: non-constrained exports and exports limited
to 100kWh/h. The results suggest that in the case with no limit on export, the
grid tariff has little influence, but ToU is economically advantageous for both
the ZEN and the DSO. When exports are limited, the subscribed capacity scheme
allows to maintain DSO revenue, while the others cut them by half. This tariff
also offers the lowest maximum peak and a good duration curve. The dynamic
tariff creates new potentially problematic peak imports despite its benefits in
other peak hours.Comment: Presented at IEEE Powertech 2019 in Milano, 6 page
Assessing the potential benefit of energy storage in emission constrained power markets using equilibrium modeling
An equilibrium model of the energy market is extended by a carbon emissions market. In addition, the mix of renewable energy sources is optimized given a limit on total generation. These two new features are integrated into an existing model to assess the effects of a carbon emissions market in a case study of the northern European power system. First, a fixed carbon emissions tax is deployed, revealing that carbon emissions can be greatly influenced by the availability of energy storage. Further, a carbon emission quota is implemented and the tax necessary to enforce the limit is calculated by the model. Based on the case studies, it is discussed how quota level and the availability of energy storage influence, among others, optimal system design and power market stakeholders.acceptedVersio
Green or blue? Enabling industrial decarbonization and demand response with hydrogen for high temperature process heating
Vinyl chloride monomer production coupled with chlor-alkali electrolysis is an industrial process that requires high temperature process heat. One option for providing this process heat in a decarbonized energy system is with either green or blue hydrogen. The demand for hydrogen with low CO 2 intensity will increase with emission restrictions, and the potential for industrial demand response will rise with higher shares of variable renewables in the electricity grid. However, knowledge regarding how the different hydrogen types affect the costs of industrial processes and their flexibility potential is scarce. Hence, we apply a cost-optimization model to assess the decarbonization of the heating process, and the flexibility of the process depending on the hydrogen source. We find that the ability to switch between both green and blue hydrogen is beneficial for the industrial actor, and that the flexibility is highest with an equal share of green and blue hydrogen.Green or blue? Enabling industrial decarbonization and demand response with hydrogen for high temperature process heatingacceptedVersio
Guidelines for Distribution System Operators on Reactive Power Provision by Electric Vehicles in Low Voltage Grids
Interaction of a glow discharge with an ion beam
The aim is to derive a fluid model, of hydrodynamic/diffusion type, describing the interaction of a glow discharge with an ion beam at atmospheric pressure
Integrated design and operational optimization of energy systems in dairies
Around 70% of worldwide industrial energy use is today based on fossil energy. Electrification of low temperature heat in this sector is pointed out as a key measure to reduce emissions. A large amount of the low temperature heat demand can be served by mature technologies, providing a possible fast way to decarbonize parts of the industry sector. Still, to reduce costs and accelerate broad, sector-wide implementation, integrating thermal and electrical energy systems will be important. Here a model is presented to analyse cost-optimal industrial energy system investments, applied to a dairy. The model uses heating, cooling and electric demands at an hourly resolution, including hourly power prices and yearly increases in energy and emission costs. The model minimizes investment, grid, energy and emission costs over a given planning period. Real data from a Norwegian dairy is used to investigate the effect on an industrial energy system subject to different future cost scenarios. The results show that an energy integrated dairy can reduce costs by 24% and emissions by 96% compared with a traditional dairy, and is cheaper to decarbonize. It is also shown that thermal energy storages provide flexibility at a low cost, eliminating the need for batteries.publishedVersio
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