Browsing by Author "Syri, Sanna"

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  • Abandoning peat in a city district heat system with wind power, heat pumps, and heat storage
    (2022-11) Javanshir, Nima; Syri, Sanna; Teräsvirta, Antti; Olkkonen, Ville
     A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
    The Finnish Government has established the target of carbon-neutrality by 2035. In Finland, district heating (DH) networks in most cities rely on carbon dioxide (CO2) intensive fuels such as coal and domestic peat. This study assesses the decarbonization of a Finnish city's DH by employing power-to-heat (P2H) technologies, including heat pumps, an electric boiler, and thermal storage together with an ambitious building energy renovation program. This study also aims to use wind power with a calculated fixed price instead of the market price for the electricity consumption of the deployed P2H units to further support electrification and decarbonization of the DH network. Bilateral contract between the wind producer and the DH operator is examined, as new wind power producers receive no subsidies in Finland. The impacts of storage capacity, electricity tax, building-level renovation, and European CO2 emission allowance (EUA) price on the DH's optimal operation and break-even price of heat production were evaluated. The optimization routine minimizes marginal production costs. The optimal scenario eliminated the carbon intensive fuel peat with more affordable heat prices, due to P2H technologies, lower electricity tax, higher EUA prices, and the renovation of buildings. Bilateral electricity contract can bring mutual benefits for the DH company and the wind producer.
  • Advanced design and operation of Energy Hub for forest industry using reliability assessment
    (2023-07-25) Talebjedi, Behnam; Laukkanen, Timo; Holmberg, Henrik; Syri, Sanna
     A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
    A large part of the refining heat production in the thermomechanical pulp mill can be recovered to supply the paper machine heat demand. This study introduces a novel approach for the heat integration of a thermomechanical pulp mill and paper machine using Energy Hub. An Energy Hub consisting of a steam generator heat pump and the electric boiler is integrated with the thermomechanical pulp mill to provide the heating demand of the paper machine. The advanced cost-efficient design and operation of the Energy Hub are investigated in this research by integrating thermo-economic analysis, reliability & availability assessment, and load profile prediction. The thermo-economic analysis combines economics and thermodynamics, which is necessary for energy system unit commitments. Reliability assessment will lead to more accurate modeling of real-life system operating conditions since system components' availability is considered in the design process. Load profile prediction estimates the Energy Hub load for the next hour, which helps with the optimal operation of the Energy Hub. Different state-of-the-art long-short-term memory (LSTM) neural network models have been developed to achieve the best time series model for refining heat prediction in the thermomechanical pulp mill. Results show that all the time series models are effective for refining heat prediction, while Bidirectional LSTM appears to perform better than others with the correlation coefficient and root mean square error of 0.9 and 0.15, respectively. In addition, the proposed Energy Hub design approach is compared with the conventional design method. The proposed design method offers a robust design that isn't impacted by unsupplied demand penalty rates. Depending on the penalty rates, the total system cost could decrease by 14%-28% utilizing the proposed design method.
  • Aggregation ready flexibility management methods for mechanical ventilation systems in buildings
    (2023-10-01) Maask, Vahur; Rosin, Argo; Korõtko, Tarmo; Thalfeldt, Martin; Syri, Sanna; Ahmadiahangar, Roya
     A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
    Increasing use of volatile renewable energy sources causes challenges in balancing supply and demand. Therefore, demand-side flexibility has rising importance for system operators and balancing authorities. Flexibility management methods are needed to integrate loads like ventilation systems of different buildings (e.g., residential and commercial) into flexibility service. However, the available methods described in research papers require further development for implementation in practice. Heating and cooling systems have received much attention from researchers, but the potential of ventilation systems has been left out of focus. Therefore, this paper provides a complete set of novel flexibility management methods for ventilation systems created from an aggregator's viewpoint. The flexibility is quantified through capacity (e.i. the amount of power consumption that can be altered), forced ventilation rate duration, and the tendered price for the service. The proposed methods were tested on a building model constructed and simulated in IDA ICE. The data processing and flexibility management methods were applied in MATLAB. Two types of ventilation systems with different sensor configurations were considered: constant and variable air volume. Forced ventilation rate duration is calculated using energy and mass balance analysis where the root means squared error was 10 to 33 min, depending on the system type, measured parameter, and sensor location. The flexibility service pricing model was tested on the 2022 years' manual frequency restoration reserve (mFRR) activation and balance energy market data.
  • Aggregators and storage of the Nordic imbalance settlement model
    (2017-12-11) Eklund, Markus
     Insinööritieteiden korkeakoulu | Master's thesis
    The increasing amount of renewables in electricity production and rapid fluctuations in weather conditions creates challenges for the electricity systems and markets. The variations in energy production disturbs the balance between electricity production and consumption. The balance can be restored by making the electricity demand more flexible with demand response and increase the amount of electricity storages. However, individual demand response resources for instance on the commercial sector and electricity storages, are often small and scattered on a wide area. Therefore, these resources should be regulated and aggregated together in order to obtain a greater impact. EU has proposed that this aggregation should be handled by a new electricity market operator called the aggregator. This thesis proposes two models of how different aggregators and their aggregated energies could be handled in the recently introduced Nordic imbalance settlement model. The aggregation models are then evaluated by interviewing different market operators from Finland, Sweden and Norway. The interviewees were asked to give their general opinions about the aggregator and their need on the Nordic electricity market. Also, more specific questions about the aggregation models were asked. The interviews revealed that there are differing opinions about the need for aggregators between the Nordic countries, which will further hamper the harmonization of the aggregator role. However, the interviewees supported more or less small-scale electricity storages and their flexibility potential. Furthermore, the interviewees questioned the sanctioning and compensation principles in the aggregation models and they proposed that sanctions and compensations should be adjusted. The thesis also discusses the state of aggregators in two European countries and in the state of California in USA. The aggregator role is slowly and steadily evolving in France and Belgium but since the aggregator is a new market role in Europe, there are still barriers that prevents the aggregator to fully participate on the market. In California, the aggregator role and the processes for handling the aggregators are more advanced than in Europe.
  • Älykkäät sähköverkot: kotitaloudet sähköntuottajina ja -varastoijina
    (2012-04-25) Biese, Mikael
     Insinööritieteiden korkeakoulu | Bachelor's thesis
  • Älykkäiden järjestelmien tuomat mahdollisuudet ja haasteet lämmitysmarkkinoilla
    (2013-04-15) Mertanen, Antti
     Insinööritieteiden korkeakoulu | Bachelor's thesis
  • Analysis of Severe Scarcity Situations in Finland’s Low Carbon Electricity System Until 2030
    (2024-12) Koivunen, Tero; Syri, Sanna
     A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
    This paper presents PLEXOS modelling of the Nordic and Baltic low-carbon electricity market until 2030, using a total of 35 different weather years’ (1982–2016) ERAA profiles as inputs for the modelling and focusing on the occurrence of severe electricity scarcity situations in Finland, analyzing their duration and depth. The expected development of generation and demand is modelled based on available authoritative sources, such as ENTSO-E TYNDP and national projections. The present amount of nuclear power in Finland and growing amounts of wind and solar generation across the Nordic electricity system are modelled. This study analyzes scarcity situations by calculating residual loads and the expected electricity spot market prices assuming the different weather years with the generation fleet and demand in 2024 and 2030 scenarios. This study finds that, despite the very significantly growing amount of variable renewable generation (42.5 TWh/a increase in wind generation from 2024 to 2030 in Finland only), the frequency and severity of scarcity situations will increase from 2024 to 2030. The main reasons are the retirement of Combined Heat and Power plants and the transition to more electrified district heating in Finland and the expected demand growth. The findings indicate that without further measures Finland is not sufficiently prepared for cold winter periods with high heating and electricity demand and events of serious scarcity can occur.
  • The Anatomy of Unaffordable Electricity in Northern Europe in 2021
    (2022-10) Jääskeläinen, Jaakko; Huhta, Kaisa; Syri, Sanna
     A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
    European electricity prices soared to unusually high levels during 2021, which exposed vulnerabilities in the economy and led to concerns about affordability. The concerns were further exacerbated in 2022, as Europe strove to cut its dependence on the Russian fossil fuel supply, as a result of the Russian invasion of Ukraine. This article explores the causes of the price increases in 2021 and assesses their likely future development by using Finland as a case example. We address a gap in the existing energy literature by elucidating the origins and future outlooks of price spikes in highly interconnected electricity markets. Based on an interdisciplinary combination of legal and qualitative data analysis, this study approaches its key objective in three stages. First, we describe the European market and its regulatory design to demonstrate the legislative framework and preconditions within which the market is expected to operate and how these rules connect to guaranteeing the affordability of electricity. Second, we explore how these preconditions functioned in practice in 2021 by analysing the wider macro-level trends that resulted in the elevated prices throughout Europe, particularly in Finland. Third, we assess the impacts of these trends on Finnish electricity price development. Based on these descriptive and predictive analyses, we show that the European market design fundamentally necessitates price variation to ensure market-based investment and energy security in the long-term. Our analysis demonstrates that the high energy prices in 2021 were, in general, the result of various weather-related, economic, and political factors. Moreover, our findings indicate that the dynamics of price formation within a Member State are complex, and in the case of Finland, strongly impacted by neighbouring markets.
  • Användning av dual-fuel-förbränning i motorteknik
    (2014-04-23) Kekäle, Kim
     Insinööritieteiden korkeakoulu | Bachelor's thesis
  • Asuntojen energiankulutus
    (2012-04-24) Puustinen, Joonas
     Insinööritieteiden korkeakoulu | Bachelor's thesis
  • Attractiveness of the emerging solar power markets in Turkey
    (2013) Jääskeläinen, Jaakko Juhana
     School of Engineering | Master's thesis
    This master's thesis analyses the suitability of solar power in Turkey. Turkey's rapidly growing population and economy are paired with an exponentially growing demand for energy. The demand is supplied with fossil fuel imports to a large extent, as Turkey's already scarce fossil fuel reservoirs are diminishing. Turkish government addresses the issues of energy security, climate change mitigation and sustainable development, and thus Turkey has ambitious plans on growing the share of renewables in power production. Moreover, Turkey has highly favourable irradiation conditions, daily and annual power demand peaks of Turkey correlate with the solar radiation and Turkey has abundant and growing hydropower capacity to meet the output fluctuation of solar power. However, despite the aforementioned assets, solar power has not yet penetrated the electricity markets of Turkey. Solar power applications are distinguished between PV (photovoltaic) and CSP (concentrating solar power) technologies. To assess the economic feasibility of solar power in Turkey, this thesis provides three case studies of the most commercially and technologically proven technologies: a residential rooftop PV system (2 kW), a utility scale ground-mounted PV system (1 MW) and a utility scale CSP system (50 MW). Both the PV studies are on-grid fixed-tilt crystalline silicon systems and the CSP system is a parabolic trough system without thermal electricity storage. The residential PV system is competitive in southern Turkey even without economic subsidies with its LCOE (liveliest cost of energy) of 146 €/MWh lower than the forecasted consumer electricity prices. The utility scale PV is highly competitive with the current economic subsidies with a LCOE of 97 €/MWh, but the LCOE is too high to compete with electricity wholesale prices in Turkey. The studied CSP system is far from economic feasibility even with the economic subsidies with a LCOE of 208 €/MWh. The biggest obstacles in PV markets have been financing of the systems and, until recently, their lack of competitiveness. Also the high inflation rate reduces attractiveness and feasibility of solar power investments in Turkey. However, during the past few years PV prices have declined dramatically, economic subsidies for solar power have improved significantly and electricity prices have grown. Furthermore, long-term trends in electricity prices and solar power system prices both favour solar power utilisation and therefore it is more likely than not, that solar power will soon penetrate the Turkish electricity markets attracting business in the meanwhile.
  • Aurinkoenergiajärjestelmien integrointi rakennuksiin Euroopassa
    (2013-11-22) Virta, Mikko
     Insinööritieteiden korkeakoulu | Bachelor's thesis
  • Aurinkoenergian hyödyntäminen alueellisessa energiantuotannossa
    (2012-04-25) Stammeier, Hanna
     Insinööritieteiden korkeakoulu | Bachelor's thesis
  • Aurinkolämmön hyödyntäminen biopolttoaineen kuivauksessa
    (2012-11-30) Lindholm, Kalevi
     Insinööritieteiden korkeakoulu | Bachelor's thesis
  • Aurinkolämpö kotitalouksien lämmönlähteenä
    (2012-11-30) Karjalainen, Siru
     Insinööritieteiden korkeakoulu | Bachelor's thesis
  • Aurinkolämpöjärjestelmät
    (2012-04-25) Autio, Miikka
     Insinööritieteiden korkeakoulu | Bachelor's thesis
  • Aurinkolämpöjärjestelmien käyttö ja levinneisyys Euroopassa
    (2013-04-23) Pieskä, Henrikki
     Insinööritieteiden korkeakoulu | Bachelor's thesis
  • Aurinkolämpösovellusten markkinakatsaus ja teknistaloudellinen selvitys
    (2018-12-10) Käyhkö, Sanna
     Insinööritieteiden korkeakoulu | Master's thesis
    Työn tavoitteena on tutkia ja löytää aurinkolämpöön ja -jäähdytykseen liittyviä teknistaloudellisesti potentiaalisia konsepteja, selvittää aurinkolämpöteknologian hyötyjä muihin lämmöntuotantomuotoihin verrattuna ja saada tietoa aurinkolämpösovellusten taloudellisesta kannattavuudesta. Keskeisiä tutkimusmenetelmiä ovat kirjallisuustutkimus sekä aurinkokeräimien toimintakykyyn liittyvät laskelmat, erilaiset data-analyysit, kannattavuuslaskelmat sekä herkkyystarkastelut. Kirjallisuustutkimus sisältää markkinakatsauksen ja siinä esitellään aurinkolämpöteknologioiden keskeiset käsitteet. Lähteinä käytetään kansainvälisiä tieteellisiä artikkeleita ja alan kirjallisuutta. Alustavien kokoluokkatarkastelujen perusteella tutkimusosassa kehitetään Suomen olosuhteisiin soveltuvia konsepteja, joille tehdään teknistaloudellinen tarkastelu. Konsepteiksi valikoituivat aurinkokaukolämpöratkaisu, aurinkolämpö lämpöpumppujen kanssa sekä aurinkojäähdytysratkaisu, joille tehtiin tarkemmat kannattavuus- ja herkkyystarkastelut. Lisäksi lopuksi aurinkokaukolämpöinvestointia verrataan biolaitosinvestointeihin. Kansainvälisten tilastojen mukaan aurinkoenergian tuotanto on kasvanut viime vuosina maailmanlaajuisesti ja kasvuennusteiden mukaan jatkaa edelleen kasvuaan. Toimivia teknisiä ja taloudellisesti kannattavia aurinkolämpöratkaisuja on jo olemassa, mutta niiden teknistaloudelliset ominaisuudet ovat kuitenkin hyvin kohde- ja sijaintikohtaisia. Tutkimuksen pohjalta voidaan todeta, että aurinkolämpöjärjestelmien kannattavuus kasvaa järjestelmäkoon kasvaessa investointi- ja ylläpitokustannusten suhteellisen osuuden laskiessa. Pinta-alan ja lämpövaraston tarve sekä auringonsäteilyn ja suurimman lämmönkulutusajankohdan kohtaamattomuus kuitenkin rajoittavat aurinkolämmölle sopivien kohteiden määrää tiiviisti rakennetulla kaupunkialueella. Työn tulosten perusteella kannattavimmat aurinkolämpöjärjestelmät ovat keräinpinta-alaltaan hyvin suuria, minkä vuoksi järjestelmät voivat olla myös aluesuunnittelun kannalta haastavia toteuttaa kaupunkiympäristössä. Aurinkolämpöjärjestelmät toteutetaan yleensä hybridijärjestelminä, jolloin ne toimivat yhdessä jonkin toisen energiantuotantomuodon tai lämpövaraston kanssa. Tällöin järjestelmä ei ole niin herkkä tuotannonvaihteluille. Aurinkokaukolämpöratkaisuissa ei kuitenkaan ole välttämätöntä investoida erikseen lämpövarastoon kaukolämpöverkon toimiessa lämpövarastona. Työn pohjalta voidaan todeta, että aurinkolämpösovelluksista kustannustehokkaimpia ovat aurinkokaukolämpö, aurinkojäähdytys sekä lämpöpumppuihin integroitavat järjestelmät. Näille konsepteille suositellaan sijaintikohtaisempaa jatkotarkastelua. Aurinkolämpöratkaisuilla on mahdollista säästää esimerkiksi biopolttoainekustannuksissa kevät-, kesä- ja syyskaudella.
  • Aurinkoöljyjärjestelmät rakennusten lämmityksessä
    (2012-04-24) Hämäläinen, Ilkka
     Insinööritieteiden korkeakoulu | Bachelor's thesis
  • Aurinkosähköjärjestelmien käyttö ja levinneisyys Euroopassa
    (2013-04-22) Nisula, Markus
     Insinööritieteiden korkeakoulu | Bachelor's thesis