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This paper evaluates various aspects of flexibility in power systems worldwide within the multi-country study framework of IEA Wind Task 25, including grid components and actions which have been favoured for enhancing flexibility in different areas/countries/regions, and how TSOs/ISOs/ utilities intend to manage variable generation in their operating strategies. One methodology to evaluate the diversity of flexibility sources is a "flexibility chart”, which can illustrate several flexibility parameters (e.g. hydro, CCGT, CHP, interconnection) in a polygonal radar (spider) chart.

The Danish energy system is undergoing a transition from a system based on storable fossil fuels to a system based on fluctuating renewable energy sources. At the same time, more of and more of the energy system is becoming electrified; transportation, heating and fuel usage in industry and elsewhere. This article investigates the development of the Danish energy system in a medium year 2030 situation as well as in a long-term year 2050 situation. The analyses are based on scenario development by the Danish Climate Commission. In the short term, it is investigated what the effects will be of having flexible or inflexible electric vehicles and individual heat pumps, and in the long term it is investigated what the effects of changes in the load profiles due to changing weights of demand sectors are. The analyses are based on energy systems simulations using EnergyPLAN and demand forecasting using the Helena model. The results show that even with a limited short-term electric car fleet, these will have a significant effect on the energy system; the energy system’s ability to integrated wind power and the demand for condensing power generation capacity in the system. Charging patterns and flexibility have significant effects on this. Likewise, individual heat pumps may affect the system operation if they are equipped with heat storages. The analyses also show that the long-term changes in electricity demand curve profiles have little impact on the energy system performance. The flexibility given by heat pumps and electric vehicles in the long-term future overshadows any effects of changes in hourly demand curve profiles. International Journal of Sustainable Energy Planning and Management, Vol 7 (2015)

Rising energy costs, anthropogenic climate change, and fossil fuel depletion calls for a concerted effort within energy planning to ensure a sustainable energy future. This article presents an overview of global energy trends focusing on energy costs, energy use and carbon dioxide emissions. Secondly, a review of contemporary work is presented focusing on national energy pathways with cases from Ireland, Denmark and Jordan, spatial issues within sustainable energyplanning and policy means to advance a sustainable energy future. International Journal of Sustainable Energy Planning and Management, Vol 1 (2014)

It is often highlighted how the transition to renewable energy supply calls for significant electricity storage. However, one has to move beyond the electricity-only focus and take a holistic energy system view to identify optimal solutions for integrating renewable energy. In this paper, an integrated cross-sector approach is used to determine the most efficient and least-cost storage options for the entire renewable energy system concluding that the best storage solutions cannot be found through analyses focusing on the individual sub-sectors. Electricity storage is not the optimum solution to integrate large inflows of fluctuating renewable energy, since more efficient and cheaper options can be found by integrating the electricity sector with other parts of the energy system and by this creating a Smart Energy System. Nevertheless, this does not imply that electricity storage should be disregarded but that it will be needed for other purposes in the future. International Journal of Sustainable Energy Planning and Management, Vol 11 (2016)

EU has determined that 10 % of all fuel used in 2020 should be replaced by a biofuel. That substitute could be biodiesel. This project deals with the possibility of replacing 10 % of the used fuel in Denmark by biodiesel. Furthermore a comparison of the economic evaluation of two different plants was done. The crucial difference between the plants was purchase of the catalyst, enzymatic or chemical, with a difference of 17.3 mil. kr. The residual from both plants is glycerol. A smaller plant was designed to produce arcrolein from glycerol. An economic evaluation of this plant was done.

In the transition towards 4th generation district heating (4GDH), supply and demand side measures have to be coordinated better than in previous generations of district heating (DH). Building’s heat demand has to be reduced, and heating installations as well as consumer behaviour have to be adapted so as to be compatible with and support lower network temperatures. It is therefore necessary to investigate and understand how consumers can be meaningfully and strategically included in the transition towards 4GDH. This paper provides a literature review of the consumer levels role in 4GDH in the transition towards 100% renewable energy systems. Current literature of 4GDH have been investigated to identify the connection and involvement of consumers in the transition. Even though consumers within the existing building mass have a large role in the transition in terms of heat savings and instalment of energy efficient technologies in the buildings are almost none of the scientific literature addressing how these actions should be implemented at consumer level. From the results of the analysis it is recommended that further research should investigate how to strengthen the coordination between supply and demand sides in order to secure the right initiatives are implemented in the right order. International Journal of Sustainable Energy Planning and Management, Vol. 29 (2020)

Department of Chemistry, Jai Narain Vyas University, Jodhpur-342 001, Rajasthan, India E-mail : krg2004@rediffmail.com Manuscript received 1 June 2006, revised 15 January 2007, accepted 17 January 2007 Brij-35, DTPA and Bismark Brown were used as surfactant, reductant and photosensitizer respectively in photogalvanic cell and photogalvanic effect was studied. The photopotential and photocurrent generated by this system were 786.0 m V and ll5.0 µA respectively. The observed conversion efficiency, fit! factor, cell performance in dark and maximum power obtained were observed 0.5192%, 0.48, 117.0 min and 54.00 µW, respectively.

Decarbonizing Sweden’s transportation sector is necessary to realize its long-term vision of eliminating net greenhouse gas (GHG) emissions from the energy system by 2050. Within this context, this study develops two scenarios for the transportation sector: one with high electrification (EVS) and the other with high biofuel and biomethane utilization (BIOS). The energy system model STREAM is utilized to compute the socioeconomic system cost and simulate an integrated transportation, electricity, gas, fuel refinery, and heat system. The results show that electrifying a high share of Sweden’s road transportation yields the least systems cost. However, in the least-cost scenario (EVS), bioenergy resources account for 57% of the final energy use in the transportation sector. Further, a sensitivity analysis shows that the costs of different types of cars are the most sensitive parameters in the comparative analysis of the scenarios. International Journal of Sustainable Energy Planning and Management, Vol 14 (2017)