Probabilistic Forecasting in Day-Ahead Electricity Markets: Simulating Peak and Off-Peak Prices

In this paper we include dependency structures for electricity price forecasting and forecasting evaluation. We work with off-peak and peak time series from the German-Austrian day-ahead price, hence we analyze bivariate data. We first estimate the mean of the two time series, and then in a second step we estimate the residuals. The mean equation is estimated by OLS and elastic net and the residuals are estimated by maximum likelihood. Our contribution is to include a bivariate jump component on a mean reverting jump diffusion model in the residuals. The models' forecasts are evaluated using four different criteria, including the energy score to measure whether the correlation structure between the time series is properly included or not. In the results it is observed that the models with bivariate jumps provide better results with the energy score, which means that it is important to consider this structure in order to properly forecast correlated time series.Comment: 30 pages, 11 figures, 3 tables and Accepted in International Journal of Forecastin

Neska kirolarien egoera eskola garaitik goi mailako txapelketeraino

33 p. : il. - E-mail del autor: [email protected] eskubideak aldarrikatuz, mugimendu feministek bide latza ibili dute. Urte askotan zehar, eta gaur egun ere, gizarteak barneratuta duen matxismoaren aurka borrokatu da, gehiengoaren ideal eta estereotipoen aurka jokatuz. Gizartean nesken diskriminazio egoerak gutxitu direla eta sexuen eskubide eta aukerak berdintzen doazela dioten arren, egundoko ibilbidea geratzen da. Beraz, elkarrizketa batzuen bidez, gaur egun goi mailako kirolarien artean neskek bizitzen dituzten diskriminazio egoerak aztertuko ditugu. Beren kiroleko lehen urteetatik gogoratzen dutena egungoarekin alderatuko da, azkenik diskriminazio egoera ezberdinetatik ateratzeko aukera posibleak identifikatuz. Hurrengo lerroetan zehar sexu eta genero kontzeptuak azalduko dira, estereotipoek sexu diskriminazioan eduki ditzakeen ondorioak aipatuz. Ondoren, neskek hezkuntzan bizi izandako eskubide eta aukera gora-beherak gainetik aipatuko dira, garrantzi handia eduki zuten zenbait lege eta hezkuntza erreforma argituz. Azkenik, neskek kirol munduan edukitako garapenari errepaso labur bat emango zaio. Elkarrizketak eta hauetatik lorturiko emaitzak aztertu ondoren, argi ikus daiteke neska kirolariek, beren egunerokoan, diskriminazio egoera ezberdin ugari bizi dituztela. Hala ere, egoera honen analisi hobe bat egiteko denbora gehiago, elkarrizketatuen kopuru handiagoa eta hauek praktikatzen duten kirol aniztasun zabalagoa beharko genuke

Parametric assessment of a building active façade by means of a combined metallic sandwich panel with an unglazed solar collector

The building sector has a poor performance in terms of energy efficiency and is looking for alternatives to reduce the use of fossil fuels on building use stage. Renewables are unlimited and solar thermal energy is a technology with a demonstrated potential. The façade is a key element able to harness renewable energy coming from the sun becoming in an Active Solar Thermal Façade (ASTF). The main purpose of this study is the development of a parametric study using a numerical model to analyze the behavior of an unglazed solar collector. Thus, evaluating different design and meteorological parameters to show their influence on the heat transfer and the efficiency. The study shows that solar irradiation and mass flow are the most influential on thermal difference. However, for the efficiency ambient temperature and inlet temperature both are the most influencing ones. In brief, a set of parameters have a significant influence on the behavior of the ASTF that are fully governed by environmental conditions. Nevertheless, there are some other parameters that can be controlled during the operation. The challenge is to make a continuous configuration of this adaptable values depending on the external situation to achieve a higher performance for the ASTF

An analysis of the potential of envelope-integrated solar heating and cooling technologies for reducing energy consumption in European climates

There is a clear trend towards the increased contribution of renewable energy at European level, and EU policies are oriented towards that direction. The building sector is no exception and presents an urgent necessity for increasing the share of renewable energy sources (RES) to reduce the impact on the environment. The aim of this paper is to examine the potential of solar heating and cooling technologies in reducing energy consumption by incorporating solar thermal and PV collectors within the building’s envelope. Although generally envisaged to be integrated in the roof, preferably oriented to the south, this study explores also their potential for integration into the façades. External climate influences both the demand for space heating and cooling (influenced by temperature) and the potential from solar renewable energy (incident global irradiation). However, a time lag exists since supply and demand peak at different times within the day as well as during the year. This study assesses the interplay of solar energy supply with heating and cooling energy demand. An analysis is performed over climate data files for five European locations, based on daily weather data. Besides the extent of incident solar irradiation, its seasonal usability is assessed with regard to the thermal demand. The impact of the inclination of solar collector devices is assessed by comparing their placement on a horizontal plane, on the inclination of maximum exposure for each climate, and on vertical planes for the four cardinal directions. As a conclusion, the utilization of solar energy for different scenarios is assessed and a discussion on the integration of solar thermal and PV collectors over façades is presented, building on the potential of these technologies for developing innovative solutions that could significantly upgrade the buildings’ energy performance in the near future

Ariketa fisikoa eta mina zein funtzio mailaren arteko erlazioa. Errebisio sistematikoa.

[EUS] Ikerketa honek sistematikoki errebisatu zuen ariketa fisikoak minarengan zein funtzioan duen eragina. Artikuluen bilaketa PUBMED eta GOOGLE SCHOLAR datu base elektronikoetan egin zen, baita errebisioan sartzen ez ziren errebisio sistematikoetako artikulu interesgarriak hartu ziren. Ikerketa guztiek jaso behar zituzten pazienteen jarduera fisiko (edo forma fisiko) mailak; astero egindako ariketa fisiko kantitatea, intentsitatea eta frekuentzia. Ondoren, neurketa horien eta pazientearen eguneroko minaren intentsitatearen arteko erlazioa begiratu zen alde batetik, edo bestela min esperimentalari zer nolako erantzuna azaltzen zuten pazienteek, jarduera fisikoaren bidez sailkaturiko taldeetan. Barneratze irizpideak 20 artikuluk bete zituzten, eta horietatik 12 artikulutan paziente sintomatikoei minari eta osasunari buruzko eskalak pasatu zitzaizkien. Hortaz gain, 6 artikulutan paziente osasuntsuak hartu eta egiten zuten ariketa fisiko mailaren arabera sailkatu ondoren, min esperimentala (Min muga, min tolerantzia, eta abar.) neurtu zitzaizkien. Beste 3 artikulutan forma fisikoak minean zuen eragina neurtu zuten; bi ikerketek ohiko mina zutenengan eta beste batek min esperimentalarengan zuen eragina. Ariketa fisiko kantitateak minarengan eragina zuela 11 artikuluk defendatzen zuten; horietatik lautan subjektu sintomatikoek ez zituzten gomendatutako jarduera fisiko kantitateak betetzen eta beste zazpi ikerketetan ikusi zen ariketa fisiko kantitate egokiek minarengan babes efektua eragiten zutela, bai min kronikoan zein esperimentalean. Ariketa fisikoaren intentsitateak minarengan eragina zuela 9 ikerketetan ikusi zen, ariketa intentsoagoak hipoalgesia nabarmenagoa eta osasunean onura gehiago eragiten zituela nabarmendu zuten. Azkenik, forma fisikoaren eragina min lunbarrean edo arazo muskuloeskeletikoetan nabaria zela azaldu zuten, forma fisiko hoberena zutenek min edo sintoma gutxiago aurkeztuz. Ondorioz, ariketa fisikoa min kronikoa prebenitzeko zein tratatzeko tresna baliagarria da, hipoalgesia eta min pertzepzioan alterazioak eragiteko duen gaitasunagatik, klinikarako oso baliagarria izanik

Experimental Thermal Performance Assessment of a Prefabricated External Insulation System for Building Retrofitting

External Thermal Insulation Composite Systems (ETICS) are increasingly used for the energy-efficient retrofit of buildings. This paper evaluates the in-situ thermal performance of a prefabricated composite panel made of PIR and concrete, by full scale testing of a prototype installed at the KUBIK test facility. Experimental results from measurement show a reduction in the thermal resistance of the ETICS assembly compared to theoretical design values. A number of phenomena have been identified causing multidimensional heat flow of conductive and convective nature,such as thermal bridges at floor slabs and anchors, and thermal bypass of the insulation causing airflow behind the ETICS.The ETIXc project consortium, composed of Sociedad Financiera y Minera, S.A. FYM- HeidelbergCement Group and Prehorquisa. This research work has been aided by the EEA Grants special funding from the Financial Mechanism of the European Economic Area (2009-2014)

District Power-To-Heat/Cool Complemented by Sewage Heat Recovery

District heating and cooling (DHC), when combined with waste or renewable energy sources, is an environmentally sound alternative to individual heating and cooling systems in buildings. In this work, the theoretical energy and economic performances of a DHC network complemented by compression heat pump and sewage heat exchanger are assessed through dynamic, year-round energy simulations. The proposed system comprises also a water storage and a PV plant. The study stems from the operational experience on a DHC network in Budapest, in which a new sewage heat recovery system is in place and provided the experimental base for assessing main operational parameters of the sewage heat exchanger, like effectiveness, parasitic energy consumption and impact of cleaning. The energy and economic potential is explored for a commercial district in Italy. It is found that the overall seasonal COP and EER are 3.10 and 3.64, while the seasonal COP and EER of the heat pump alone achieve 3.74 and 4.03, respectively. The economic feasibility is investigated by means of the levelized cost of heating and cooling (LCOHC). With an overall LCOHC between 79.1 and 89.9 €/MWh, the proposed system can be an attractive solution with respect to individual heat pumps.This research was funded by the European Commission, H2020-project Heat4Cool, grant number 723925. The work has also been supported by the Swiss State Secretariat for Education, Research and Innovation (SERI) under Contract No. 16.0082

Assessment on the Efficiency of an Active Solar Thermal Facade: Study of the Effect of Dynamic Parameters and Experimental Analysis When Coupled/Uncoupled to a Heat Pump

The building sector presents poor performance in terms of energy efficiency and is looking for effective alternatives aimed at reducing the use of fossil fuels. The facade is a key element able to harness renewable energy as an Active Solar Thermal Facade (ASTF). The main purpose of this study is the assessment of a novel design concept based on a steel sandwich panel technology. The performance of the active system will be first addressed by a parametric study in order to analyze its behavior and secondly, by describing a real case based on an experimental test by connecting the active panels to a heat pump. The study shows the impact of solar irradiation and mass flow on the thermal jump achieved, while ambient and fluid inlet temperatures are the most influencing parameters in the efficiency of the facade. When coupled to the heat pump, results from a measurement campaign demonstrate a remarkable improvement in the performance of the ASTF. The results presented provide significant proof about the benefits of a synergetic combination of both technologies—solar facades and heat pumps—as efficient alternatives for the building sector, aiming to improve energy efficiency as well as reduce their dependence on non-renewable sources.This research was partially funded by the Basque Government through IT781-13 and IT1314-19 research groups and by the University of the Basque Country UPV/EHU through PES17/25. Additionally, TECNALIA Research & Innovation supported the research activities research through a cooperation agreement (PT10516) with UPV/EHU

Linear Responses in Time-dependent Hartree-Fock-Bogoliubov Method with Gogny Interaction

A numerical method to integrate the time-dependent Hartree-Fock Bogoliubov (TDHFB) equations with Gogny interaction is proposed. The feasibility of the TDHFB code is illustrated by the conservation of the energy, particle numbers, and center-of-mass in the small amplitude vibrations of oxygen 20. The TDHFB code is applied to the isoscalar quadrupole and/or isovector dipole vibrations in the linear (small amplitude) region in oxygen isotopes (masses A = 18,20,22 and 24), titanium isotopes (A = 44,50,52 and 54), neon isotope (A = 26), and magnesium isotopes (A = 24 and 34). The isoscalar quadrupole and isovector dipole strength functions are calculated from the expectation values of the isoscalar quadrupole and isovector dipole moments.Comment: 10 pages, 13 figure