Energy system transition pathways to meet the global electricity demand for ambitious climate targets and cost competitiveness.

This study presents a novel energy system modelling approach for analysis and comparison of global energy transition pathways for decarbonisation of the electricity sector. The results of the International Energy Agency (IEA), and the Teske/DLR scenarios are each reproduced. Additionally, five new energy transition trajectories, called LUT, are presented. The research examines the feasibility of each scenario across nine major regions in 5-year intervals, from 2015 to 2050, under a uniform modelling environment with identical technical and financial assumptions. The main differences between the energy transition paths are identified across: (1) the average electricity generation costs; (2) energy diversity; (3) system flexibility; (4) energy security; and, (5) transition dynamics. All LUT and Teske/DLR scenarios are transitioned to zero CO2 emissions and a 100% renewable energy system by 2050 at the latest. Results reveal that the LUT scenarios are the least-cost pathways, while the Teske/DLR scenarios are centred around energy diversity with slightly higher LCOE of around 10-20%. The IEA shares similarities with the Teske/DLR scenarios in terms of energy diversity yet depends on continued use of fossil fuels with carbon capture and storage, and nuclear power. The IEA scenario based on current governmental policies present a worst-case situation regarding CO2 emissions reduction, climate change and overall system costs

True Cost of Solar Hydrogen

Green hydrogen will be an essential part of the future 100% sustainable energy and industry system. Up to one-third of the required solar and wind electricity would eventually be used for water electrolysis to produce hydrogen, increasing the cumulative electrolyzer capacity to about 17 TWel by 2050. The key method applied in this research is a learning curve approach for the key technologies, i.e., solar photovoltaics (PV) and water electrolyzers, and levelized cost of hydrogen (LCOH). Sensitivities for the hydrogen demand and various input parameters are considered. Electrolyzer capital expenditure (CAPEX) for a large utility-scale system is expected to decrease from the current 400 €/kWel to 240 €/kWel by 2030 and to 80 €/kWel by 2050. With the continuing solar PV cost decrease, this will lead to an LCOH decrease from the current 31–81 €/MWhH2,LHV (1.0–2.7 €/kgH2) to 20–54 €/MWhH2,LHV (0.7–1.8 €/kgH2) by 2030 and 10–27 €/MWhH2,LHV (0.3–0.9 €/kgH2) by 2050, depending on the location. The share of PV electricity cost in the LCOH will increase from the current 63% to 74% by 2050.This study was made under the framework of the European Technology and Innovation Platform for Photovoltaics (ETIP PV). Open access of this study has been supported by the ETIP PV Secretariat which works in the framework of the ETIP PV-SEC II project. The project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement no. 825669. A.J.-W. works at the European Commission – Joint Research Centre (JRC), Ispra, Italy. The views expressed are purely those of the author and may not in any circumstances be regarded as stating an official position of the European Commission

Identifying predictors of attitudes towards local onshore wind development with reference to an English case study

The threats posed by climate change are placing governments under increasing pressure to meet electricity demand from low-carbon sources. In many countries, including the UK, legislation is in place to ensure the continued expansion of renewable energy capacity. Onshore wind turbines are expected to play a key role in achieving these aims. However, despite high levels of public support for onshore wind development in principle, specific projects often experience local opposition. Traditionally this difference in general and specific attitudes has been attributed to NIMBYism (not in my back yard), but evidence is increasingly calling this assumption into question. This study used multiple regression analysis to identify what factors might predict attitudes towards mooted wind development in Sheffield, England. We report on the attitudes of two groups; one group (target) living close to four sites earmarked for development and an unaffected comparison group (comparison). We found little evidence of NIMBYism amongst members of the target group; instead, differences between general and specific attitudes appeared attributable to uncertainty regarding the proposals. The results are discussed with respect to literature highlighting the importance of early, continued and responsive community involvement in combating local opposition and facilitating the deployment of onshore wind turbines. (C) 2009 Elsevier Ltd. All rights reserved

Transformerless topologies for grid-connected single-phase photovoltaic inverters

NOTICE: this is the author’s version of a work that was accepted for publication in . Changes resulting from the publishing process, such as peer review, editing, corrections,structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in RENEWABLE AND SUSTAINABLE ENERGY REVIEWS, [VOL 15 , ISSUE 7, (07/2011)] DOI 10.1016/j.rser.2011.03.034[EN] In order to improve the efficiency and reduce the cost of a photovoltaic system, the use of transformerless photovoltaic inverters is an alternative of increasing interest. However, this topology needs to be studied in detail, as it presents some problems related to the galvanic connection between the grid and the photovoltaic generator (e.g. efficiency degradation and safety problems). In this paper, a review of grid-connected single-phase photovoltaic inverters based on transformerless topologies has been carried out. On the one hand, some alternatives based on classical topologies have been presented. On the other hand, alternatives based on multi-level inverter topologies have been studied, showing up that no leakage current is generated in comparison to classical topologies. © 2011 Elsevier Ltd All rights reserved.This work is supported by the Spanish Ministry of Science and Innovation under grant ENE2009-13998-C02-02.Patrao Herrero, I.; Figueres Amorós, E.; González Espín, FJ.; Garcerá Sanfeliú, G. (2011). Transformerless topologies for grid-connected single-phase photovoltaic inverters. Renewable and Sustainable Energy Reviews. 15(7):3423-3431. https://doi.org/10.1016/j.rser.2011.03.034S3423343115

DIFFUSION LENGTH MEASUREMENTS OF HETEROJUNCTION THIN FILMS BY JUNCTION-EBIC

Junction-EBIC is used to characterize minority carrier diffusion lengths in heterojunction thin films. Because the submicron diffusion lengths of our CuInSe2-(Zn,Cd)S film devices and the diameter of the generation volume are in the same range, EBIC interpretation taking the generation volume as a point source is difficult. In our model we use a finite size of the generation volume to fit the EBIC measurements. It is possible to measure with a higher accelerating voltage and for that reason effects caused by surface recombination and high injection can be avoided. In this paper the model is described and experimental results are presented