Papers by Poul A Østergaard
Energy, 2011
Energy system analyses on the basis of fast and simple tools have proven particularly useful for ... more Energy system analyses on the basis of fast and simple tools have proven particularly useful for interdisciplinary planning projects with frequent iterations and re-evaluation of alternative scenarios. As such, the tool "EnergyPLAN" is used for hourly balanced and spatially aggregate annual analyses of energy scenarios. For the relatively fast dynamics of electrical energy systems, additional requirements need to be formulated to justify the technical feasibility of the respective scenario. In this article, the comparison is made of energy scenarios for the Danish island of Bornholm. First, the model is verified on the basis of the existing energy mix on Bornholm as an islanded energy system. Future energy scenarios for the year 2030 are analysed to study a feasible technology mix for a higher share of wind power. Finally, the results of the hourly simulations are compared to dynamic frequency simulations incorporating the Vehicle-to-grid technology. The results indicate how the EnergyPLAN model may be improved in terms of intra-hour variability, stability and ancillary services to achieve a better reflection of energy and power capacity requirements.
Sustainable Cities and Communities Design Handbook, 2018
Abstract In 2006, a number of Danish energy experts proposed that Denmark should convert the supp... more Abstract In 2006, a number of Danish energy experts proposed that Denmark should convert the supply of a specific town to 100% renewable energy by 2015. The experts suggested Frederikshavn in the northern part of Denmark for the following reasons. The town area of 25,000 inhabitants is well defined, the local support is high, and Frederikshavn already has a number of large wind turbines at the harbor. In February 2007, the city council unanimously decided to go for the project and set up a project organization involving utilities and municipality administrators. The local industry and the Aalborg University are also involved in the project. This chapter presents the methodology of mapping the existing energy system, including transport, and defining the share of renewable energy, which is approximately 20% at present. It introduces a proposal for a potential 100% renewable energy system for the year 2015 and a number of realistic short-term first steps, which will raise the share of renewable energy in Frederikshavn to approximately 40% by 2009 or 2010. This chapter describes detailed hour-by-hour energy system analyses of the proposal for a 100% renewable energy system. Also, it relates the proposal to the perspective of converting Denmark to a 100% renewable energy supply system.
This chapter introduces the concept of smart energy systems. As opposed to the smart grid concept... more This chapter introduces the concept of smart energy systems. As opposed to the smart grid concept, which takes focuses solely on the electricity sector, smart energy systems includes the entire energy system in its approach to identifying suitable energy infrastructure designs and operating strategies. The typical smart grid focus on the electricity sector often leads to the definition of transmission lines, flexible electricity demands, and electricity storage as the primary means to deal with the integration of fluctuating renewable sources. However, due to the intermittent nature of wind power and similar sources, these measures are not very effective or cost-efficient. The most effective and least-cost solutions are found when the electricity sector is combined with the heating sector and/or the transportation sector. Moreover, the combination of electricity and gas infrastructures may play an important role in the design of future renewable energy systems.
Applied Energy, 2021
Survey of current trends and challenges in energy system modelling tools (N = 54). • Tool feature... more Survey of current trends and challenges in energy system modelling tools (N = 54). • Tool features, linkages, user accessibility and policy application were reviewed. • Growing coverage of cross-sectoral synergies, open access, and improved temporal detail. • Challenges in representing high resolution energy demand in all sectors. • Key issues remain in understanding tool coupling, accessibility & perceived policy-relevance.
Energy Strategy Reviews, 2013
Users may download and print one copy of any publication from the public portal for the purpose... more Users may download and print one copy of any publication from the public portal for the purpose of private study or research. You may not further distribute the material or use it for any profit-making activity or commercial gain You may freely distribute the URL identifying the publication in the public portal If you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediately and investigate your claim.
International Journal of Sustainable Energy, 2013
Nepal is heavily dependent on the traditional energy sources and imported fossil fuel, which has ... more Nepal is heavily dependent on the traditional energy sources and imported fossil fuel, which has an adverse impact on the environment and economy. Renewable energy technologies promoted in the country are regarded as a means of satisfying rural energy needs of the country for operating different rural end-uses. In this context, this article is prepared to investigate energy alternatives to pump drinking water in one of the remote rural village of Nepal, which has no means of running water source. Analyses in this article are based on the formulation of three technical scenarios of water pumping using petro-diesel, jatropha-based biodiesel and solar photovoltaic pumps. The technical system design consists of system sizing of prime mover (engine, solar panel and pumps) and estimation of reservoir capacity, which are based on the annual aggregate water demand modelling. With these investigations, detailed financial modelling is carried out in a spreadsheet to compare the alternatives on the basis of the economic parameters; net present value, equivalent annualised cost and levelised cost of water pumping. Analysis is carried out considering different influential parameters; water head, discharge, incentives on the investments, which have effects on the cost of pumped water. Likewise, in case of biodiesel-based system, different yield rate of jatropha plants is also considered in estimating the cost of producing biodiesel. It is found that for operating a biodiesel-based pumping system for the study area, the levelised cost of pumping 1 L of water is higher than that of a solar pump and even higher when compared with diesel, if the seed yield per plant is less than 2 kg and without subsidy on the investment cost of cultivation and processing. With the productivity of 2.5 kg/plant, a biodiesel-based system is more attractive than that of the diesel-based pump, but still remains more expensive than that of solar pump. From the technical perspective (reliability and easiness in operation) and economic evaluation of the technical alternatives, solar pumping system is found to be the most viable solution to pump drinking water in the project area.
Energy, 2013
Abstract According to some future Danish energy scenarios, biomass will become one of the two mai... more Abstract According to some future Danish energy scenarios, biomass will become one of the two main pillars of the future energy system accompanied by wind power. The biomass can be used for generating heat and electricity, and as a transportation fuel in a future energy system according to the scenarios. This article compares the value of using biomass as a heat source and for electricity generation in a 100% renewable energy system context. The comparison is done by assuming an incremental decrease in the biomass available for the electricity and heat sector, respectively. The assumed scenarios for the decrease of biomass are made by use of an hourly energy system analysis model, EnergyPLAN. The results are shown in terms of system configuration, biomass fuel efficiency, system cost, and impacts on the export of electricity. It is concluded that the reduction of biomass in the heat sector is better than the alternative reduction in the electricity sector in every aspects except biomass fuel efficiency.
Energy, 2000
... the new technologies are widely distributed throughout the areas of consumption, and theimple... more ... the new technologies are widely distributed throughout the areas of consumption, and theimplementation is therefore ... Approximately 10% are located in rural areas and are not suited for district heating. ... as the then-planned changes to the grid for the coming decade and a half. ...
International Journal of Sustainable Energy Planning and Management, May 6, 2014
Climate change mitigation calls for energy systems minimising end-use demands, optimising the fue... more Climate change mitigation calls for energy systems minimising end-use demands, optimising the fuel efficiency of conversion systems, increasing the use of renewable energy sources and exploiting synergies wherever possible. In parallel, global fresh water resources are strained due to amongst others population and wealth increase and competitive water uses from agriculture and industry is causing many nations to turn to desalination technologies. This article investigates a Jordanian energy scenario with two different desalination technologies; reverse osmosis (RO) driven by electricity and Multi Stage Flash (MSF) desalination driven by Cogeneration of Heat and Power (CHP). The two systems impact the energy systems in different ways due to the technologies' particular characteristics. The systems are analyses in the energy systems analysis model EnergyPLAN to determine the impacts on energy system performance. Results indicate that RO and MSF are similar in fuel use. While there is no use of waste heat from condensing mode plants, efficiencies for CHP and MSF are not sufficiently good to results in lower fuel usage than RO. The Jordanian energy system is somewhat inflexible giving cause to Critical Excess Electricity Production (CEEP) even at relatively modest wind power penetrations. Here RO assists the energy system in decreasing CEEP-and even more if water storage is applied.
roadmap-europe-2050-second-prestudy-for-the-eu27%28306a5052-a882-4af9-a5da-87efa36efeaa%29.html G... more roadmap-europe-2050-second-prestudy-for-the-eu27%28306a5052-a882-4af9-a5da-87efa36efeaa%29.html General rights Copyright and moral rights for the publications made accessible in the public portal are retained by the authors and/or other copyright owners and it is a condition of accessing publications that users recognise and abide by the legal requirements associated with these rights. ? Users may download and print one copy of any publication from the public portal for the purpose of private study or research. ? You may not further distribute the material or use it for any profit-making activity or commercial gain ? You may freely distribute the URL identifying the publication in the public portal ? PREFACE Although the heating and cooling sector is very large in size and already provides low and nocarbon solutions, it has largely been overlooked in all scenarios exploring the energy future towards 2050. The Energy Roadmap 2050 published by the European Commission rightly acknowledges that renewable heating and cooling is vital to decarbonisation and that a costoptimal policy choice between insulating buildings and systematically using waste-heat needs to be found. Yet, the Roadmap omits a thorough analysis of the heating and cooling sector. Against this background, during early 2011, Euroheat & Power, Aalborg University and Halmstad University further discussed the possibility for developing a major European research project called Heat Roadmap Europe, focusing on the future European heat and cooling market and its interactions with other parts of the energy market. In order to prepare for a full project proposal, a pre-study research project was established. The five major purposes of the pre-study were identified as: Validation of the proposed research methodology. Indication of possible results from a future full research study. Early warning information to policy-makers about the quality of official EU energy roadmaps with respect to the expansion of district heating systems. Giving an alternative future projection to many all-electric future heat scenarios. Information leaflet for tentative partners in a future research consortium concerning Heat Roadmap Europe. The Aalborg and Halmstad universities have performed this pre-study in cooperation according to a methodology based on energy modelling and mapping of local conditions reflecting the possible future district heating opportunities.
In this paper we launch the design of Smart Energy Systems through the 100% renewable energy syst... more In this paper we launch the design of Smart Energy Systems through the 100% renewable energy system analyses and research behind the CEESA research project. The transition from fossil fuels towards the integration of more and more renewable energy requires rethinking and redesign of the energy system. Traditionally a lot of focus internationally is put on the electricity sector to solve the integration puzzle focusing on electricity storage technologies e.g. batteries, hydrogen storage and on (electricity) smart grids. In Smart Energy Systems the focus is integration of the electricity, heating and transport sectors, and on using the flexibility in demands and various short term and longer term storage in the different sectors. Such a redesign also entails that the Smart Energy System is comprised of a number of smart grid infrastructures for different sectors in the energy system, i.e. the electricity grids, district heating (cooling) grids, gas grids and fuel infrastructure.
About the authors of this report This report is written by a group of energy researchers and expe... more About the authors of this report This report is written by a group of energy researchers and experts from Danish universities and independent consultants. The group represents many years of experience within a wide range of expertise covering academic studies as well as hands on experience with the operation and management of the Danish energy system.
roadmap-europe-2050%28a855df3d-d211-45db-80de-94ee528aca8d%29.html General rights Copyright and m... more roadmap-europe-2050%28a855df3d-d211-45db-80de-94ee528aca8d%29.html General rights Copyright and moral rights for the publications made accessible in the public portal are retained by the authors and/or other copyright owners and it is a condition of accessing publications that users recognise and abide by the legal requirements associated with these rights. ? Users may download and print one copy of any publication from the public portal for the purpose of private study or research. ? You may not further distribute the material or use it for any profit-making activity or commercial gain ? You may freely distribute the URL identifying the publication in the public portal ?
ABSTRACT This work shows the optimization of natural ventilation within buildings at the stage of... more ABSTRACT This work shows the optimization of natural ventilation within buildings at the stage of design and behaviour of the occupants. An evaluation is done by coupled multizone air modelling and thermal building simulation by using a deterministic set of input factors comprising among others climate, local environment, building characteristics, building systems, behaviour of occupants, heat loads. Selected deterministic input factors were varied to generate additional information applied in an optimization loop. With that, it is found that the optimal solution depends to a great deal on the possibility of combined optimization of the behaviour of occupants with a lesser extent of the design building.
Isp Skriftserie, 2008
At modest penetration wind power merely substitutes electricity generated typically at thermal po... more At modest penetration wind power merely substitutes electricity generated typically at thermal power plants and thereby only giving economic benefits comparable to the saved marginal fuel and operation and maintenance costs. At higher penetrations, it becomes increasingly important for the energy system to be able to operate without costly reserve capacity awaiting fluctuations in demand or wind power generation that need be countered. Existing interconnections of transmission systems are mainly in order to assist in reducing reserve capacity in thermal power generation systems. While indeed relevant in thermal systems, this is typically even more so in renewable energy based systems, where fluctuations
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Papers by Poul A Østergaard