Beta 1


Title Lagring af El
Author Andersen, Marie Katrine Bech
Supervisor Elmegaard, Brian (Termiske Energisystemer, Institut for Mekanisk Teknologi, Danmarks Tekniske Universitet, DTU, DK-2800 Kgs. Lyngby, Denmark)
Institution Technical University of Denmark, DTU, DK-2800 Kgs. Lyngby, Denmark
Thesis level Master's thesis
Year 2009
Abstract Mængden af fossile brændstoffer svinder hastigt ind, og udledning af drivhusgasser er et problem, der modtager megen opmærksomhed. Det betyder, at vedvarende energi fra eksempelvis vind i stigende grad er aktuelt. Produktionen af elektricitet fra vedvarende energikilder er svært at administrere, og sker sjældent i god overensstemmelse med forbrugermønstre. Denne rapport indeholder en komparativ analyse af el-til-elvirkningsgraderne og det økonomiske potentiale for varianter af fire forskellige metoder til lagring af energi. Fokus er rettet mod energimanagement, hvilket indebærer at kunne udjævne uoverensstemmelserne mellem produktion af vindkraft og forbrug af el i Danmark. Det økonomiske potentiale er baseret på data for det danske elmarked i årene 2005, 2006 og 2007. Systemerne der analyseres, er et konventionelt CAES-anlæg og et CAES-anlæg med varmelager, reversible brændselsceller, underjordisk PHS og varmepumper, der bruger CO2 som kølemiddel. Det er også undersøgt, hvad mulighederne er for produktion af elektricitet med en Organic Rankine Cycle drevet af fjernvarmevand produceret på CO2-varmepumper. Af de analyserede er det mest rentable system CAES med varmelager med en el-til-elvirkningsgrad på 59 %. Det økonomiske potentiale lægger sig tæt op ad det for konventionelt CAES, men ud fra et miljøøkonomisk synspunkt er CAES med varmelager at foretrække, da naturgasforbruget er lavere. Underjordisk PHS, hvor et aquifer udgør det nederste lager har en el-til-elvirkningsgrad på 79 %. Grundet meget høje omkostninger forbundet med konstruktion af PHS-anlæg, er det dog svært at gøre lagring af el med underjordisk PHS rentabelt. Tendensen er dog, at ved grundig overvejelse og planlægning af driften af underjordisk PHS er der potentiale for at forbedre anlægsøkonomien betragteligt. Lagring af elektricitet med CO2-varmepumper og reversible brændselsceller er uøkonomisk grundet lave el-til-elvirkningsgrader. Derimod kan en betydelig udvikling af varmepumpeteknologi betyde, at salg af fjernvarme produceret på CO2-varmpeumper bliver fordelagtigt.
Abstract The rapid decrease in the amount of fossil fuels and greenhouse gas emissions are issues, which are currently receiving much attention. This means that renewable energy from e.g. wind is becoming increasingly relevant. The production of electricity from renewable energy sources is hard to administrate, and it rarely occurs in good accordance with electricity consumption patterns. This report contains a comparative analysis of the electricity-to-electricity efficiencies and the financial potential for variants of four different energy storage methods. Energy management is brought into focus, which entails being able to even out the discrepancy between production of wind power and the consumption of electricity in Denmark. The financial potential is based on data for the Danish electricity market in 2005, 2006 and 2007. The systems that have been analysed are a conventional CAES plant and a CAES plant with heat storage, reversible fuel cells, underground PHS and heat pumps that use CO2 as a refrigerant. A further analysis has been carried out to examine the potential for electricity production with an Organic Rankine Cycle driven by district heating water produced on CO2 heat pumps. The system that proves most cost-effective is CAES with heat storage, which has an electricity-to-electricity efficiency of 59 %. Its financial potential is somewhat comparable to that of a conventional CAES plant, but since CAES with heat storage uses less natural gas, it is preferable from an environmental point of view. Underground PHS where the lower reservoir consists of an aquifer has an electricity-to-electricity efficiency of 79 %. Due to high construction costs, underground PHS is not easily made cost-effective. However, the tendency is that by thorough consideration and planning of the underground PHS operation, the economy of such a plant can be improved significantly. Electricity storage with CO2 heat pumps and reversible fuel cells is financially unfeasible due to low electricity-to-electricity efficiencies. Nevertheless, a considerable technological refinement of heat pump technology might make the production of district heat on CO2 heat pumps profitable.
Imprint Technical University of Denmark (DTU) : Kgs. Lyngby, Denmark
Fulltext
Original PDF Rapport.pdf (2.42 MB)
Admin Creation date: 2009-11-05    Update date: 2010-10-28    Source: dtu    ID: 252022    Original MXD