• Energy Research

A sustainable energy supply requires a stepped-up change to renewable sources of energy. By 2050, assuming the demand on the security of supply remains the same, at least 60 percent of the gross final consumption of energy in Germany is to be covered by renewable energy sources. A major challenge is the natural fluctuation in power output, particularly with wind and solar power. In order to guarantee a consistent supply of electrical energy, there are a number of flexibility options available to help balance out the difference between energy supply and demand. In addition to grid expansion, load management and the use of highly flexible conventional power plants, this includes the utilisation of suitable storage methods. Nanotechnology innovations are already contributing to improved energy conversion, storage and transmission. In future, nanotechnology solutions (including the targeted use of nanomaterials) could play a prominent role in the energy sector, especially in the development of innovative approaches to energy storage.

The sustainability argument that more peat grows in Finland than is used does not hold. On designated peatlands, growth is about 85 times slower than peat use; growth elsewhere in Finland does not add to available resources. Claiming undisturbed peatlands as carbon sinks for sustainable peat use is also misleading as anthropogenic carbon sources require additional sinks, not natural ones. Undisturbed peatlands usually emit significant quantities of methane. About 57 000 km(2) of forestry drained peatlands now have effectively stopped emitting methane, and temporarily accumulate more carbon annually than earlier. These greenhouse reducing aspects are only modestly compensated or 'used' by emissions from peat used for energy. However, as forests mature and the peat underneath continues to oxidise, the new carbon sink will eventually turn into a carbon source. Multiple claims of this very same anthropogenic carbon sink (perhaps by the peat, paper and timber industry), i.e. double counting, may be avoided by certifying these sinks. After peat harvesting (liberating in the order of 375 kg atmospheric carbon per m(2)), wood in a production/harvest cycle may be grown (at 0.1 kgC/m(2) per a) on the now available area, as a renewable energy source. These numbers indicate the slow rate at which these cycles, that are in principle carbon neutral in themselves, help compensate for the carbon emissions from the earlier use of peat by avoiding the emissions of fossil fuels otherwise used. (C) 2001 Elsevier Science B.V. All rights reserved.

Akumulace energie, a to jak elektrické tak energie jiného druhu je tématem kterému je v dnešní době věnována větší a větší pozornost. Důvodem jsou převážně obnovitelné zdroje energie (OZE), ale také zlepšení účinnosti dodávek elektrické energie a elektromobilita. Právě účelem této práce je nastínit některé způsoby akumulace energie,popsat některá média ,která se v daných akumulátorech mohou vyskytovat a popsat jejich praktickou realizaci. Nadále pak určit porovnávací kritéria ,která budou sloužit k porovnání dříve popsaných způsobů akumulace energie a jejich médií. Na závěr bude uvedeno jaké způsoby a média jsou nejvhodnější pro zvolené aplikace. ; Obhájeno ; The accumulation of energy, both electrical and other form, is a topic that is still receiving more and more attention nowadays. The reason is mainly renewable energy sources (RES), but also improving efficiency of electricity supply and electromobility. The purpose of this thesis is to outline some ways of energy accumulation, describe some media used in this systems, and describe their practical implementation. Criteria for comparison will then be determined, which will be used to compare the previously described methods of energy storage and their media. Finally, methods and media that are most suitable for the selected applications will be stated.

To address the climate change, the development of electrification is being rapidly conducted worldwide, especially in automobile industry. Regarding mobile machinery, many companies also have been forced to develop electrification technologies with a focus on electric mini excavators. Nevertheless, concerning middle class or larger sizes of excavators, it is not regarded that electrification technologies are the best solution, demanding huge battery capacity. Hence, it is expected that machines powered by internal combustion engines (ICE) will continue to be indispensable. To make hydraulic excavator more efficient, numerous studies to reduce throttling losses being major losses in hydraulic systems have been conducted. However, less throttling losses are likely to lead to inefficient operation considering the ICE efficiency map.In order to solve this issue, a hydraulic system called STEAM being one of the constant pressure systems has been proposed to improve overall system efficiency. Important features of this system are that the ICE can be operated at the most efficient point, and recoverable energy is allowed to be recuperated by accumulators. However, it might be difficult to be accepted by the industry due to using a multitude of valves. Alternatively, a three pump open center system allows engineers to design simple layout of the machines and enables machines to provide fluid efficiently by three pumps with less throttling losses. It seems that there is a new possibility by merging both architectures. Therefore, the purpose of this study is set to design a new hybrid architecture which combines an open center system with STEAM.In this thesis, basic principles and a design guideline to develop a hydraulic circuit of the new hydraulic architecture are discussed. To confirm the improvement of the system efficiency, simulations and experiments with the test rig are carried out and achievements are discussed. Dissertation, RWTH Aachen University, 2023; Düren : Shaker Verlag, Reihe Fluidtechnik. D 115, 1 Online-Ressource : Illustrationen (2024). doi:10.18154/RWTH-2024-04089 = Dissertation, RWTH Aachen University, 2023 Published by Shaker Verlag, Düren

Place accumulation of elements in all systems is objectively necessary. Similarly, in the RES energy systems is their role is irreplaceable. The renewable energy systems can use different types of storage: electrochemical batteries, supercapacitors, superconducting units, rotary, pneumatic and others. The renewable energy systems can use different types of storage: electrochemical batteries, supercapacitors, superconducting units, rotary, pneumatic and others. The article deals with the design size sets of batteries to allow short-term deposit of the required amount of electricity. ; Miesto akumulačných prvkov vo všetkých systémoch je objektívne nevyhnutná. Rovnako aj v energetických systémoch OZE je ich úloha nenahraditeľná. V systémoch OZE je možné použiť rôzne typy zásobníkov: elektrochemické akumulátory, superkondenzátory, supravodičové jednotky, rotačné, tlakovzdušné a iné. Tieto zásobníky sú označované ako krátkodobé, aby zosúladili výrobu elektrickej energie a jej spotrebu. Článok sa zaoberá návrhom veľkosti zostavy akumulátorov tak, aby umožnili krátkodobé uloženie požadovaného množstva elektrickej energie.

This article discusses application of nanomodified heat accumulators on the basis of paraffin modified by carbon nanostructures for various technological processes aiming at increase in their energy efficiency. Thermal and physical properties of nanomodified paraffins have been studied. Procedure of adaptation of heat accumulating materials for various operation modes of industrial processes is presented. Copyright © EM International.