217 resultados para Talvitie-Kella, Tuuli
Resumo:
An electric system based on renewable energy faces challenges concerning the storage and utilization of energy due to the intermittent and seasonal nature of renewable energy sources. Wind and solar photovoltaic power productions are variable and difficult to predict, and thus electricity storage will be needed in the case of basic power production. Hydrogen’s energetic potential lies in its ability and versatility to store chemical energy, to serve as an energy carrier and as feedstock for various industries. Hydrogen is also used e.g. in the production of biofuels. The amount of energy produced during hydrogen combustion is higher than any other fuel’s on a mass basis with a higher-heating-value of 39.4 kWh/kg. However, even though hydrogen is the most abundant element in the universe, on Earth most hydrogen exists in molecular forms such as water. Therefore, hydrogen must be produced and there are various methods to do so. Today, the majority hydrogen comes from fossil fuels, mainly from steam methane reforming, and only about 4 % of global hydrogen comes from water electrolysis. Combination of electrolytic production of hydrogen from water and supply of renewable energy is attracting more interest due to the sustainability and the increased flexibility of the resulting energy system. The preferred option for intermittent hydrogen storage is pressurization in tanks since at ambient conditions the volumetric energy density of hydrogen is low, and pressurized tanks are efficient and affordable when the cycling rate is high. Pressurized hydrogen enables energy storage in larger capacities compared to battery technologies and additionally the energy can be stored for longer periods of time, on a time scale of months. In this thesis, the thermodynamics and electrochemistry associated with water electrolysis are described. The main water electrolysis technologies are presented with state-of-the-art specifications. Finally, a Power-to-Hydrogen infrastructure design for Lappeenranta University of Technology is presented. Laboratory setup for water electrolysis is specified and factors affecting its commissioning in Finland are presented.
Resumo:
Tulevaisuudessa tuuli- ja aurinkovoiman osuus sähköntuotannosta tulee kasvamaan. Näiden uusiutuvien energiamuotojen tuotanto kuitenkin vaihtelee sääolosuhteiden mukaan. Tästä johtuen tarvitaan lisää säätövoimaa, jotta voidaan vastata sähkönkulutukseen tuuli- ja aurinkosähkön tuotannon laskiessa. Tässä työssä tarkastellaan mahdollisuutta toteuttaa sähkönkulutuksen ja tuotannon tasapainottaminen Suomessa sähkön varastoinnin avulla sekä ydinvoiman soveltuvuutta säätövoimaksi ja ydinsähkön varastoinnin kannattavuutta. Työssä vertaillaan mahdollisuuksia sähkön varastointiteknologioiksi, joista valitaan potentiaalisimmat vaihtoehdot kustannus- ja soveltuvuustarkasteluun. Varastointikapasiteetin tarvetta tarkastellaan Suomen nykyisen sähkönkulutuksen ja -tuotannon mukaan sekä tilanteessa, jossa tuuli- ja aurinkovoiman osuus on molemmilla 15 % kokonaistuotantokapasiteetista. Vanhempien sekä nykyaikaisten ydinvoimaloiden soveltuvuutta säätövoimaksi tarkastellaan laitosten säädettävyyden perusteella. Ydinvoimalaa on kuitenkin kannattavinta käyttää mahdollisimman suurella käyttökertoimella, joten tarkastelussa on myös mahdollisuus varastoida sähköä tilanteissa, joissa tuotantoa jouduttaisiin rajoittamaan. Varastointiteknologioiden ja eri skenaarioissa vaadittujen varastointikapasiteettien perusteella voidaan todeta, ettei sähkönkulutuksen ja -tuotannon tasapainottaminen sähkön varastoinnilla ole kannattavaa nykyisillä varastointikustannuksilla ja sähkön hinnoilla. Ydinvoiman voidaan todeta soveltuvan hyvin säätövoimaksi ominaisuuksien puolesta, mutta taloudellisesti se ei ole paras vaihtoehto. Ydinvoimalla tuotetun sähkön varastointi ei ole tällä hetkellä Suomessa kannattavaa matalien sähkön hintojen ja korkeiden varastointikustannusten vuoksi. Sähkön varastoinnista on mahdollista tulla kannattavaa 2020-luvulla. Tämä edellyttää Yhdysvaltojen energiaministeriön asettaman strategian toteutumista, jonka tavoitteena on varastoimalla tuotetun sähkön kustannusten saaminen alle 75 €/MWh.
Resumo:
The global interest towards renewable energy production such as wind and solar energy is increasing, which in turn calls for new energy storage concepts due to the larger share of intermittent energy production. Power-to-gas solutions can be utilized to convert surplus electricity to chemical energy which can be stored for extended periods of time. The energy storage concept explored in this thesis is an integrated energy storage tank connected to an oxy-fuel combustion plant. Using this approach, flue gases from the plant could be fed directly into the storage tank and later converted into synthetic natural gas by utilizing electrolysis-methanation route. This work utilizes computational fluid dynamics to model the desublimation of carbon dioxide inside a storage tank containing cryogenic liquid, such as liquefied natural gas. Numerical modelling enables the evaluation of the transient flow patterns caused by the desublimation, as well as general fluid behaviour inside the tank. Based on simulations the stability of the cryogenic storage and the magnitude of the key parameters can be evaluated.
Resumo:
Muuttuva sähköntuotantorakenne yhdessä Euroopan yhdentyvien sähkömarkkinoiden kanssa muuttaa energiayhtiöiden toimintaympäristöä tulevaisuudessa. Markkinoilta poistu-va säätökykyinen lauhdevoima ja lisääntyvä säiden mukaan vaihteleva tuuli- ja aurin-koenergia lisäävät säätövoiman tarvetta energiajärjestelmässä. Osa lisääntyvästä säätövoi-man tarpeesta voidaan kattaa kulutuksen kysyntäjoustoa lisäämällä. Tässä työssä tavoitteena on kehittää Savon Voima Oyj:lle kysyntäjoutopalvelu yritysasiak-kaille. Työssä kartoitetaan kysyntäjouston eri markkinapaikkojen mahdollisuuksia kysyntä-jouston toteuttamiselle, sekä käydään läpi niiden asettamia rajoitteita kysyntäjouston to-teuttamisen kannalta. Työn osana kehitettyä kysyntäjouston potentiaalin laskentatyökalua käytetään arvioitaessa valittujen pilottiasiakkaiden potentiaalia Elspot-markkinoille osallistuvan kysyntäjouston osalta. Laskennan tulosten perusteella kysyntäjouston toteuttaminen Elspot-markkinoille on kannattavaa valittujen pilottiasiakkaiden kohdalla. Työssä käydään läpi kysyntäjoustopalvelun prosessia, sen vaiheita sekä huomioon otettavia asioita tarjottaessa kysyntäjoustopalvelua yrityksille. Lopuksi esitetään liiketoimintamalli, jolla palvelua lähdetään yritysasiakkaille tarjoamaan. Liiketoimintamallissa esitetään koh-deryhmät ja markkinat kysyntäjouston toteuttamiselle.
Resumo:
Teollisuuden rakennemuutoksen myötä pk-yrityskanta on Etelä-Karjalan alueen elinvoimaisuudelle tärkeämpi kuin koskaan. Kehittyäkseen pienistä keskikokoisiksi yritykset tarvitsevat lisää osaamista paitsi johtoon myös hallituksiinsa. Tämä tiivistelmään on koottu Pk-yritysten hallitustoiminta Etelä-Karjalassa -hankkeen tuloksia. Hankkeen keskeisenä tavoitteena oli vahvistaa Etelä-Karjalassa sijaitsevien pk-kokoluokan yritysten hallitustyötä ja hallitusten hyödyntämismahdollisuuksia sekä lisätä pk-yrityksissä toimivien hallitusjäsenten osaamista pk-yritysten hallitusjäseniltä vaadittavista taidoista ja osaamisalueista. Tiivistelmä on käytännönläheinen ja lyhyt esitys pk-yritysten hallitustoiminnan erityispiirteistä. Hanketta rahoittivat Euroopan sosiaalirahasto ja Hämeen ELY-keskus ja se toteutettiin Lappeenrannan teknillisen yliopiston toimesta vuosien 2014-2015 aikana.
Resumo:
In recent years, technological advancements in microelectronics and sensor technologies have revolutionized the field of electrical engineering. New manufacturing techniques have enabled a higher level of integration that has combined sensors and electronics into compact and inexpensive systems. Previously, the challenge in measurements was to understand the operation of the electronics and sensors, but this has now changed. Nowadays, the challenge in measurement instrumentation lies in mastering the whole system, not just the electronics. To address this issue, this doctoral dissertation studies whether it would be beneficial to consider a measurement system as a whole from the physical phenomena to the digital recording device, where each piece of the measurement system affects the system performance, rather than as a system consisting of small independent parts such as a sensor or an amplifier that could be designed separately. The objective of this doctoral dissertation is to describe in depth the development of the measurement system taking into account the challenges caused by the electrical and mechanical requirements and the measurement environment. The work is done as an empirical case study in two example applications that are both intended for scientific studies. The cases are a light sensitive biological sensor used in imaging and a gas electron multiplier detector for particle physics. The study showed that in these two cases there were a number of different parts of the measurement system that interacted with each other. Without considering these interactions, the reliability of the measurement may be compromised, which may lead to wrong conclusions about the measurement. For this reason it is beneficial to conceptualize the measurement system as a whole from the physical phenomena to the digital recording device where each piece of the measurement system affects the system performance. The results work as examples of how a measurement system can be successfully constructed to support a study of sensors and electronics.
Resumo:
Finnish companies have usually formed a strategic alliance as entry mode when entering the Japanese market. However, these strategic alliances have not been studied in a general level and it remains unknown, what kind cooperation the Finnish companies are operating with their Japanese partners. Especially Finnish companies that aims to penetrate the Japanese market are eager to know more about this. The recent studies on topic have focused on a single industry or company and that is why more general level study was needed. The purpose of this study is to analyze types of Finnish–Japanese strategic alliances from the Finnish point of view. The analysis is conducted by answering the questions what strategic alliance types appear in the strategic alliances between Japanese and Finnish companies, and how commitment affects strategic alliance type. This study also examines how committed Finnish–Japanese strategic alliances are. In this study multiple case study was selected as research method. The data is collected by interviewing six representative of Finnish companies in Japan individually. Multiple case study was chosen for this study, because this study is interested in the topic in general level and this research method is suitable for this kind of research. From the interviews common attributes were pointed out and from them the big picture of the topic was created. Types of strategic alliances were determined by using previous literature on that topic. Two different types of strategic alliance were discovered: supplier alliance which is the most common one and learning alliance. The commitment of strategic alliance was measured visually by utilizing a figure that was modified for this study.The figure is originally based on earlier studies on strategic alliance types and their connection to ownership and commitment. By utilizing the figure it was noticed that commitment affects strategic alliance types: the more there is commitment involved, the more there is cooperation. Finnish–Japanese strategic alliances are not very committed despite they have existed for a long time. However, there is potential to be more committed. That is why Finnish companies should increase the commitment and attract the partners to develop the strategic alliances, because it would possible increase competitive advantage. This would be beneficial to all members within the strategic alliance.
Resumo:
Teema: Kansainvälisyys.