arXiv subjects

Christoph Winkler

Publications and source records attributed to Christoph Winkler.

18 recordsLinked to original sources

arXiv2026

Which Top Energy-Intensive Manufacturing Countries Can Compete in a Renewable Energy Future?

In a world increasingly powered by renewables and aiming for greenhouse gas-neutral industrial production, the future competitiveness of todays top manufacturing countries is questioned. This study applies detailed energy system modeling to quantify the Renewable Pull, an incentive for industry relocation exerted by countries with favorable renewable conditions. Results reveal that the Renewable Pull is not a cross-industrial phenomenon but strongly depends on the relationship between energy costs and transport costs. The intensity of the Renewable Pull varies, with China, India, and Japan facing a significantly stronger effect than Germany and the United States. Incorporating national capital cost assumptions proves critical, reducing Germanys Renewable Pull by a factor of six and positioning it as the second least affected top manufacturing country after Saudi Arabia. Using Germany as a case study, the analysis moreover illustrates that targeted import strategies, especially within the EU, can nearly eliminate the Renewable Pull, offering policymakers clear options for risk mitigation.

eess.SY↗

arXiv2025

The Striking Impact of Natural Hazard Risk on Global Green Hydrogen Cost

Due to climate change, natural hazards that affect energy infrastructure will become more frequent in the future. However, to incorporate natural hazard risk into infrastructure investment decisions, we develop an approach to translate this risk into discount rates. Thus, our newly developed discount rate approach incorporates both economic risk and natural hazard risk. To illustrate the impact of including the risk of natural hazards, we apply country-specific discount rates for hydrogen production costs. The country-specific relative difference in hydrogen generation cost ranges from a 96% surplus in the Philippines to a -63% cost reduction in Kyrgyzstan compared to a discount rate that only consists of economic risks. The inclusion of natural hazard risk changes the cost ranking of technologies as outcome of energy system models and thus policy recommendations. The derived discount rates for 254 countries worldwide are published in this publication for further use.

econ.GN↗

arXiv2025

Towards high resolution, validated and open global wind power assessments

Wind power is expected to play a crucial role in future net-zero energy systems, but wind power simulations to support deployment strategies vary drastically in their results, hindering reliable design decisions. Therefore, we present a transparent, open source, validated and evaluated, global wind power simulation tool ETHOS.RESKit.Wind with high spatial resolution and customizable designs for both onshore and offshore wind turbines. The tool provides a comprehensive validation and calibration procedure using over 16 million global measurements from metrerological masts and wind turbine sites. We achieve a global average capacity factor mean error of 0.006 and Pearson correlation of 0.865. In addition, we evaluate its performance against several aggregated and statistical sources of wind power generation. The release of ETHOS.RESKit.Wind is a step towards a fully open source and open data approach to accurate wind power modeling by incorporating the most comprehensive simulation advances in one model.

physics.soc-ph↗

arXiv2024

High-Resolution Rooftop-PV Potential Assessment for a Resilient Energy System in Ukraine

Rooftop photovoltaic (RTPV) systems are essential for building a decarbonized and, due to its decentralized structure, more resilient energy system, and are particularly important for Ukraine, where recent conflicts have damaged more than half of its electricity and heat supply capacity. Favorable solar irradiation conditions make Ukraine a strong candidate for large-scale PV deployment, but effective policy requires detailed data on spatial and temporal generation potential. This study fills the data gap by using open-source satellite building footprint data corrected with high-resolution data from eastern Germany. This approach allowed accurate estimates of rooftop area and PV capacity and generation across Ukraine, with simulations revealing a capacity potential of 238.8 GW and a generation potential of 290 TWh/a excluding north-facing. The majority of this potential is located in oblasts (provinces) across the country with large cities such as Donetsk, Dnipro or Kyiv and surroundings. These results, validated against previous studies and available as open data, confirm Ukraine's significant potential for RTPV, supporting both energy resilience and climate goals.

physics.soc-ph↗

arXiv2024

Mapping Local Green Hydrogen Cost-Potentials by a Multidisciplinary Approach

For fast-tracking climate change response, green hydrogen is key for achieving greenhouse gas neutral energy systems. Especially Sub-Saharan Africa can benefit from it enabling an increased access to clean energy through utilizing its beneficial conditions for renewable energies. However, developing green hydrogen strategies for Sub-Saharan Africa requires highly detailed and consistent information ranging from technical, environmental, economic, and social dimensions, which is currently lacking in literature. Therefore, this paper provides a comprehensive novel approach embedding the required range of disciplines to analyze green hydrogen cost-potentials in Sub-Saharan Africa. This approach stretches from a dedicated land eligibility based on local preferences, a location specific renewable energy simulation, locally derived sustainable groundwater limitations under climate change, an optimization of local hydrogen energy systems, and a socio-economic indicator-based impact analysis. The capability of the approach is shown for case study regions in Sub-Saharan Africa highlighting the need for a unified, interdisciplinary approach.

econ.GN↗

arXiv2023

Green Hydrogen Cost-Potentials for Global Trade

Green hydrogen is expected to be traded globally in future greenhouse gas neutral energy systems. However, there is still a lack of temporally- and spatially-explicit cost-potentials for green hydrogen considering the full process chain, which are necessary for creating effective global strategies. Therefore, this study provides such detailed cost-potential-curves for 28 selected countries worldwide until 2050, using an optimizing energy systems approach based on open-field photovoltaics (PV) and onshore wind. The results reveal huge hydrogen potentials (>1,500 PWhLHV/a) and 79 PWhLHV/a at costs below 2.30 EUR/kg in 2050, dominated by solar-rich countries in Africa and the Middle East. Decentralized PV-based hydrogen production, even in wind-rich countries, is always preferred. Supplying sustainable water for hydrogen production is needed while having minor impact on hydrogen cost. Additional costs for imports from democratic regions are only total 7% higher. Hence, such regions could boost the geostrategic security of supply for greenhouse gas neutral energy systems.

econ.GN↗

arXiv2021

INTEGRAL reloaded: spacecraft, instruments and ground system

ESA's INTErnational Gamma-Ray Astrophysics Laboratory (INTEGRAL) was launched on 17 Oct 2002 at 06:41 CEST. Since then, it has been providing long, uninterrupted observations (up to about 47 hr, or 170 ksec, per satellite orbit of 2.7 days) with a large field-of-view (fully coded: 100 deg^2), msec time resolution, keV energy resolution, polarization measurements, as well as additional coverage in the optical. This is realized by two main instruments in the 15 keV to 10 MeV range, the spectrometer SPI (spectral resolution 3 keV at 1.8 MeV) and the imager IBIS (angular resolution 12 arcmin FWHM), complemented by X-ray (JEM-X; 3-35 keV) and optical (OMC; Johnson V-band) monitors. All instruments are co-aligned to simultaneously observe the target region. A particle radiation monitor (IREM) measures charged particle fluxes near the spacecraft. The Anti-coincidence subsystems of the main instruments are also efficient all-sky gamma-ray detectors, which provide omni-directional monitoring above ~75 keV. INTEGRAL can also rapidly (within a couple of hours) re-point and conduct Target of Opportunity observations. INTEGRAL has build an impressive legacy: e.g. discovery of >600 new high-energy sources; first-ever direct detection of 56Ni and 56Co radio-active decay lines from a Type Ia supernova; new insights on positron annihilation in the Galactic bulge and disk; pioneering gamma-ray polarization studies. INTEGRAL is also a successful in multi-messenger astronomy: INTEGRAL found the first prompt electromagnetic radiation in coincidence with a binary neutron star merger. More than 1750 papers based on INTEGRAL data have been published in refereed journals. Here we give a comprehensive update of the satellite status after more than 18 years of operations in a harsh space environment, and an account of the successful Ground Segment.

astro-ph.IM↗

arXiv2021

15 years of Galactic surveys and hard X-ray Background measurements

The INTEGRAL hard X-ray surveys have proven to be of fundamental importance. INTEGRAL has mapped the Galactic plane with its large field of view and excellent sensitivity. Such hard X-ray snapshots of the whole Milky Way on a time scale of a year are beyond the capabilities of past and current narrow-FOV grazing incidence X-ray telescopes. By expanding the INTEGRAL X-ray survey into shorter timescales, a productive search for transient X-ray emitters was made possible. In more than fifteen years of operation, the INTEGRAL observatory has given us a sharper view of the hard X-ray sky, and provided the triggers for many follow-up campaigns from radio frequencies to gamma-rays. In addition to conducting a census of hard X-ray sources across the entire sky, INTEGRAL has carried out, through Earth occultation maneuvers, unique observations of the large-scale cosmic X-ray background, which will without question be included in the annals of X-ray astronomy as one of the mission's most salient contribution to our understanding of the hard X-ray sky.

astro-ph.HE↗

arXiv2012

INTEGRAL: status of the mission - after 10 years

The ESA gamma-ray observatory INTEGRAL, launched on 17 October 2002, continues to produce a wealth of discoveries and new results on compact high energy Galactic objects,nuclear gamma-ray line emission, diffuse line and continuum emission, cosmic background radiation, AGN, high energy transients and sky surveys. Ten years after launch, thespacecraft, ground segment and payload are in excellent state-of-health, and INTEGRAL is continuing its scientific operations well beyond its 5-year technical design lifetime until, at least, 31December 2014. This papersummarizes the current status of INTEGRAL.

astro-ph.HE↗

arXiv2011

INTEGRAL: science highlights and future prospects

ESA's hard X-ray and soft gamma-ray observatory INTEGRAL is covering the 3 keV to 10 MeV energy band, with excellent sensitivity during long and uninterrupted observations of a large field of view (~100 square degrees), with ms time resolution and keV energy resolution. It links the energy band of pointed soft X-ray missions such as XMM-Newton with that of high-energy gamma-ray space missions such as Fermi and ground based TeV observatories. Key results obtained so far include the first sky map in the light of the 511 keV annihilation emission, the discovery of a new class of high mass X-ray binaries and detection of polarization in cosmic high energy radiation. For the foreseeable future, INTEGRAL will remain the only observatory allowing the study of nucleosynthesis in our Galaxy, including the long overdue next nearby supernova, through high-resolution gamma-ray line spectroscopy. Science results to date and expected for the coming mission years span a wide range of high-energy astrophysics, including studies of the distribution of positrons in the Galaxy; reflection of gamma-rays off clouds in the interstellar medium near the Galactic Centre; studies of black holes and neutron stars particularly in high- mass systems; gamma-ray polarization measurements for X-ray binaries and gamma-ray bursts, and sensitive detection capabilities for obscured active galaxies with more than 1000 expected to be found until 2014. This paper summarizes scientific highlights obtained since INTEGRAL's launch in 2002, and outlines prospects for the INTEGRAL mission.

astro-ph.HE↗

arXiv2011

INTEGRAL - status of the mission

The ESA gamma-ray observatory INTEGRAL, launched on 17 October 2002, continues to produce a wealth of discoveries and new results on compact high energy Galactic objects, nuclear gamma-ray line emission, diffuse line and continuum emission, cosmic background radiation, AGN, high energy transients and sky surveys. The mission's technical status is healthy and INTEGRAL is continuing its scientific operations well beyond its 5-year technical design lifetime until, at least, 31 December 2014. This paper describes the current status of INTEGRAL including the spacecraft technical state-of-health and the scientific observing programme including its on-going and future multi-year "legacy" programmes.

astro-ph.HE↗

arXiv2009

INTEGRAL - a status report

The ESA gamma-ray observatory INTEGRAL, launched on 17 October 2002, continues to produce a wealth of discoveries and new results on compact high energy Galactic objects, nuclear gamma-ray line emission, diffuse line and continuum emission, cosmic background radiation, AGN, high energy transients and sky surveys. The observing programme, fully open to the scientific community at large, is built from the community's feedback to the Announcements of Opportunity, issued about once per year. The mission's technical status is healthy and INTEGRAL is continuing its scientific operations well beyond its 5-year technical design lifetime. This paper will briefly summarize the overall current status.

astro-ph.HE↗

arXiv2009

The first outburst of the new magnetar candidate SGR 0501+4516

We report here on the outburst onset and evolution of the new Soft Gamma Repeater SGR 0501+4516. We monitored the new SGR with XMM-Newton starting on 2008 August 23, one day after the source became burst-active, and continuing with 4 more observations, with the last one on 2008 September 30. Combining the data with the Swift-XRT and Suzaku data, we modelled the outburst decay over 160 days, and we found that the source flux decreased exponentially with a timescale of t_c=23.8 days. In the first XMM-Newton observation a large number of short X-ray bursts were observed, the rate of which decayed drastically in the following observations. We found large changes in the spectral and timing behavior of the source during the outburst, with softening emission as the flux decayed, and the non-thermal soft X-ray spectral component fading faster than the thermal one. Almost simultaneously to our XMM-Newton observations (on 2008 August 29 and September 2), we observed the source in the hard X-ray range with INTEGRAL, which clearly detected the source up to ~100keV in the first pointing, while giving only upper limits during the second pointing, discovering a variable hard X-ray component fading in less than 10 days after the bursting activation. We performed a phase-coherent X-ray timing analysis over about 160 days starting with the burst activation and found evidence of a strong second derivative period component (\ddot{P} = -1.6(4)x10^{-19} s/s^{-2}). Thanks to the phase-connection, we were able to study the the phase-resolved spectral evolution of SGR 0501+4516 in great detail. We also report on the ROSAT quiescent source data, taken back in 1992 when the source exhibits a flux ~80 times lower than that measured during the outburst, and a rather soft, thermal spectrum.

astro-ph.HE↗

arXiv2007

INTEGRAL and New Classes of High-Mass X-ray Binaries

The gamma-ray observatory INTEGRAL, launched in October 2002, produces a wealth of discoveries and new results on compact high energy Galactic objects, nuclear gamma-ray line emission, diffuse line and continuum emission, cosmic background radiation, AGN and high energy transients. Two important serendipitous discoveries made by the INTEGRAL mission are new classes of X-ray binaries, namely the highly-obscured high-mass X-ray binaries, and the super-giant fast transients. In this paper I will review the current status of these discoveries.

astro-ph↗

arXiv2007

Soft gamma-ray galactic ridge emission as unveiled by SPI aboard INTEGRAL

The origin of the soft gamma-ray (200 keV - 1 MeV) galactic ridge emission is one of the long-standing mysteries in the field of high-energy astrophysics. Population studies at lower energies have shown that emission from accreting compact objects gradually recedes in this domain, leaving place to another source of gamma-ray emission that is characterised by a hard power-law spectrum extending from 100 keV up to 100 MeV The nature of this hard component has remained so far elusive, partly due to the lack of sufficiently sensitive imaging telescopes that would be able to unveil the spatial distribution of the emission. The SPI telescope aboard INTEGRAL allows now for the first time the simultaneous imaging of diffuse and point-like emission in the soft gamma-ray regime. We present here all-sky images of the soft gamma-ray continuum emission that clearly reveal the morphology of the different emission components. We discuss the implications of our results on the nature of underlying emission processes and we put our results in perspective of GLAST studies of diffuse galactic continuum emission.

astro-ph↗

arXiv2006

Radioactive 26Al and massive stars in the Galaxy

Gamma-rays from radioactive 26Al (half life ~7.2 10^5 yr) provide a 'snapshot' view of ongoing nucleosynthesis in the Galaxy. The Galaxy is relatively transparent to such gamma-rays, and emission has been found concentrated along the plane of the Galaxy. This led to the conclusion1 that massive stars throughout the Galaxy dominate the production of 26Al. On the other hand, meteoritic data show locally-produced 26Al, perhaps from spallation reactions in the protosolar disk. Furthermore, prominent gamma-ray emission from the Cygnus region suggests that a substantial fraction of Galactic 26Al could originate in localized star-forming regions. Here we report high spectral resolution measurements of 26Al emission at 1808.65 keV, which demonstrate that the 26Al source regions corotate with the Galaxy, supporting its Galaxy-wide origin. We determine a present-day equilibrium mass of 2.8 (+/-0.8) M_sol of 26Al. We use this to estimate that the frequency of core collapse (i.e. type Ib/c and type II) supernovae to be 1.9(+/- 1.1) events per century.

astro-ph↗

arXiv2001

The INTEGRAL Core Observing Programme

The Core Programme (CP) of the INTEGRAL mission is defined as the portion of the scientific observing programme covering the guaranteed time observations for the PI collaborations and other members of the INTEGRAL Science Working Team. During the first two years of the mission, the guaranteed observing time uses 35% (year 1) and 30% (year 2) of the total annual observing time (~26.6x10^{6}s per year). The Core Programme consists of three elements: a deep exposure of the Galactic central radian, regular (weekly) scans of the Galactic plane and pointed observations. This paper describes the current status of the INTEGRAL Core Programme and summarizes the key elements.

astro-ph↗

arXiv1997

The Locations of Gamma-Ray Bursts Measured by COMPTEL

The COMPTEL instrument on the Compton Gamma Ray Observatory is used to measure the locations of gamma-ray bursts through direct imaging of MeV photons. In a comprehensive search, we have detected and localized 29 bursts observed between 1991 April 19 and 1995 May 31. The average location accuracy of these events is 1.25$\arcdeg$ (1$σ$), including a systematic error of $\sim0.5\arcdeg$, which is verified through comparison with Interplanetary Network (IPN) timing annuli. The combination of COMPTEL and IPN measurements results in locations for 26 of the bursts with an average ``error box'' area of only $\sim$0.3 deg$^2$ (1$σ$). We find that the angular distribution of COMPTEL burst locations is consistent with large-scale isotropy and that there is no statistically significant evidence of small-angle auto-correlations. We conclude that there is no compelling evidence for burst repetition since no more than two of the events (or $\sim$7% of the 29 bursts) could possibly have come from the same source. We also find that there is no significant correlation between the burst locations and either Abell clusters of galaxies or radio-quiet quasars. Agreement between individual COMPTEL locations and IPN annuli places a lower limit of $\sim$100~AU (95% confidence) on the distance to the stronger bursts.

astro-ph↗