Browsing by Author "Hast, Aira"
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Item Affärsmodeller för värmebaserade energisystem(2014-12-09) Grahn, Elina; Hast, Aira; Insinööritieteiden korkeakoulu; Paatero, JukkaItem Assessment of risks and cost-efficiency of national greenhouse gas abatement actions in Finland(2011) Hast, Aira; Ekholm, Tommi; Matematiikan ja systeemianalyysin laitos; Perustieteiden korkeakoulu; School of Science; Salo, AhtiAccording to the EU climate and energy package Finland should reduce greenhouse gas (GHG) emissions in national, non-trading sectors (non-ETS) at least 16 % below 2005 levels by 2020. In order to meet this target Finland has to implement GHG abatement activities. A situation where mitigation costs should be as low as possible is studied in this Thesis. To minimize the costs, mitigation activities with the best cost-efficiency should be chosen when forming optimal abatement portfolios. However, the amount of GHG reductions and costs are uncertain with every abatement activity and therefore portfolios involve risks to reduce emissions less than predicted or cause higher costs than estimated beforehand. The objective of this Thesis is to build portfolios which fulfil the reduction target. Each portfolio consists of activities that are chosen to be implemented in the examined timeline 2010-2020 and also the year they will be implemented. In this Thesis abatement activities are chosen among 17 independent mitigation actions. To form an optimal portfolio for different levels of GHG reductions a stochastic optimization model is built. The amounts of the risks related to the costs and reductions in different portfolios are then compared. The results from this analysis show that uncertainties in costs and reductions are almost equal in every examined efficient portfolio, when the reductions are gained by national mitigation actions. It also seems that the risk to reduce emissions less than expected cannot be lowered even if the expected value of costs is raised. The probability to meet the reduction target seems to depend strongly on the expected value of costs, so that a higher probability to meet the target involves higher costs. In addition to this it can also be seen that increasing probability to meet the target in higher standard of probability requires higher relative costs than in lower standard of probability because marginal abatement costs are increasing in function of gained reductions. The results show that some abatement actions are chosen in nearly all efficient portfolios while other actions are chosen extremely seldom. To meet the reduction target the Member States of EU can trade their non-ETS allocations. Two cases are compared to each other in this Thesis. In the first case the Member States have to meet the target by national mitigation actions, and in the second case the Member States can also trade non-ETS allocations in 2020. The possibility of trading allocations changes the set of implemented actions and postpones their optimal timings because optimization is done by minimizing the present value of overall costs. The portfolios that minimize overall costs are also studied so that comparison is made by examining how the costs, reductions gained by national mitigation actions and uncertainties related to them differ from each other in these two cases. The results prove that overall costs are approximately 10 % lower when the Member States can trade allocations. On the other hand, when trading allocations is possible, the risk to exceed the expected costs increases because the price of allocation unit is very uncertain. Sensitivity analysis is performed for cost minimizing portfolios in different cases so that overall costs and gained reductions are studied separately. Uncertainty in gained reductions is caused by the same sources in both cases. Yet, the variables causing uncertainty in costs are somewhat different in different cases.Item Consumer Demand of Renewable Energy Services - Case Studies on Finland, Germany, Great Britain, USA and China(Aalto University, 2014) Hast, Aira; McDermott, Liisa; Syri, Sanna; Järvelä, Marja; Huuskonen, Maija; Alimohammadisagvand, Behrang; Cross, Sam; Syrjämäki, Eija; Energiatekniikan laitos; Department of Energy Technology; Energy Efficiency and Systems; Insinööritieteiden korkeakoulu; School of EngineeringKULMA project investigated consumer demand of so-called green energy products in various countries to understand better the motivations and preferences of consumers and the societal prerequisites and barriers of renewable energy. In addition to Finland, the target countries were Germany, Great Britain, USA and China, i.e. important export countries for the Finnish Cleantech industry. KULMA project was realised during 2012-2014 by Aalto University, Department of Energy Technology, and Jyväskylä University, Department of Social Sciences. The main funding came through the Strategic research openings instrument of Tekes, the Finnish Funding Agency for Innovation. We investigated the green electricity products available for consumers in the selected European countries, their popularity, origin and typical prices compared to standard electricity products. In the USA, we investigated the situation of renewable energy and local attitudes via sociological methods in Texas and in West Virginia. We found that transparent and clear information about the impacts of a green energy product are essential, when offering them to consumers. Local strategies are important with view to promoting consistent political will and stakeholder involvement for advancing renewable energy. Renewable energy has beneficial effects especially if the production of the technology or the fuel is local. The new industry must also have local acceptance. Previous know-how and industrial tradition often help in the creation of new local industry.Item Consumers’ attitudes to support green energy: A case study in Shanghai(Multidisciplinary Digital Publishing Institute (MDPI), 2019-06-20) Vand, Behrang; Hast, Aira; Bozorg, Sanaz; Li, Zelin; Syri, Sanna; Deng, Shuai; Department of Mechanical Engineering; Department of Built Environment; Energy efficiency and systems; University of Sheffield; Tianjin UniversityResidents’ willingness to use green energy products is a major concern for different stakeholders and policymakers due to the reformed Chinese electricity market since 2015. This study focused on the Chinese consumer’s willingness to opt and pay for environmentally-friendly electricity sources in Shanghai’s residential sector. A questionnaire survey was used to find out the influence of gender, age, education, awareness and income level on consumers’ attitudes to alter their energy sources to green ones. The results indicated that income level and awareness are significant barriers in the usage of green energy products. Increasing the respondent’s awareness about the issues of non-green energy products convinced 97% of them to change their electricity sources completely or partly, in line with their monthly income. This clearly shows that clarifying the benefits of green energy products is a key tool to achieve a green environment in China.Item Demand response potential of district heating and ventilation in an educational office building(Taylor and Francis Ltd., 2020-03-15) Vand, Behrang; Martin, Kristian; Jokisalo, Juha; Kosonen, Risto; Hast, Aira; Department of Mechanical Engineering; Energy efficiency and systems; University of Sheffield; Granlund OyThis study examines the influence of demand-response control strategies on thermal conditions, indoor air CO2 concentration, and heating energy cost and consumption in an educational office building heated by a district heating system in a cold climate. The real-time pricing-based demand response is applied for space heating, heating of ventilation, and adjustment of airflow rates. The ventilation analysis covers both constant and variable air volumes systems. The applied demand-response algorithms regulate room air temperature set-points for space heating, temperature set-point for supply air, and CO2 set-point adjusted with the variable air volume ventilation system. The accepted room air temperature range was 20-24.5 degrees C and CO2 concentration within 800-1200 ppm. This study was conducted with the validated dynamic building simulation tool IDA ICE. The results illustrate that the maximum yearly savings by demand response of space heating and ventilation with the constant air volume ventilation system are around 3 and 6% for the heating energy consumption and heating energy cost, respectively. For the variable air volume system, the heating energy consumption, heating energy cost, electricity consumption, and electricity cost saved by demand-response control can be up to 8, 11, 9, and 2%, respectively.Item District heating in cities as a part of low-carbon energy system(2018-06-01) Hast, Aira; Syri, Sanna; Lekavičius, Vidas; Galinis, Arvydas; Department of Mechanical Engineering; Energy efficiency and systems; Lithuanian Energy InstituteIn this paper, district heating scenarios towards carbon neutral district heat production in 2050 were formed for Helsinki region, Warsaw and Kaunas based on the plans and goals of the studied cities and the companies supplying district heat in these regions. It was found that increased use of biomass and waste as well as utilization of geothermal and waste heat could be expected in the studied regions in the future. Increased energy efficiency and carbon capture and storage technologies could also be utilized. According to the results, the annual emissions in Helsinki region could be cut by 90% by 2050 compared to the reference case and the average heat production costs increase only by 16%. In Warsaw, emissions were cut by 75% by 2050 but the heat production costs increased by 40%. In Kaunas, emissions can be cut from 0.102 to 0.087 million tonnes of carbon dioxide by 2050 with modest cost increase (29%). Yet, if the emissions are cut to zero, the marginal heat production costs increase by 55%. The cost increase thus depends strongly on the case and in order to limit the increase of heating costs and energy poverty, diversified use of different technologies should be considered.Item District heating in cities as a part of low-carbon energy system(2017) Hast, Aira; Syri, Sanna; Lekavičius, Vidas; Galinis, Arvydas; Department of Mechanical Engineering; Energy efficiency and systems; Lithuanian Energy InstituteIn this paper, district heating (DH) scenarios that are sustainable in terms of CO2 emissions and costs are formed and analysed. Three different cases i.e. the Helsinki region, Warsaw and Kaunas, are modelled, and the plans and goal of the cities and the companies supplying DH in the studied regions are reviewed. The aim of this study is to analyse how carbon neutrality could be reached in the studied DH systems by 2050. It was found that increased use of biomass and waste as well as utilization of geothermal and waste heat could be expected in the studied regions in the future. In addition, increasing energy efficiency and lowering heat losses in the DH network is important especially in Warsaw. Carbon capture and storage technologies could also play an important role in reducing emissions in the future but this would increase the heat production costs significantly.Item Energiatehokkuusjärjestelmän ja ISO 50001 -standardin vertailu(2013-04-22) Huuhtanen, Juhani; Hast, Aira; Insinööritieteiden korkeakoulu; Syri, SannaItem Green energy products in the United Kingdom, Germany and Finland(EDP Sciences, 2014) Hast, Aira; McDermott, Liisa; Järvelä, Marja; Syri, Sanna; Department of Energy Technology; Sarkadi, Livia; Kroó, Norbert; Armaroli, Nicoli; Ongena, Josef; McEvoy, Augustin; Fülöp, ZsoltIn liberalized electricity markets, suppliers are offering several kinds of voluntary green electricity products marketed as environmentally friendly. This paper focuses on the development of these voluntary markets at household level in the UK, Germany and Finland. Since there are already existing renewable energy policies regulating and encouraging the use of renewable energy, it is important to consider whether voluntary products offer real additional benefits above these policies. Problems such as double counting or re-marketing hydropower produced in existing plants are identified. According to our study, the demand varies between countries: in Germany the number of green electricity customers has increased and is also higher than in the UK or Finland. Typically the average additional cost to consumer from buying green electricity product instead of standard electricity product is in the range of 0–5% in all studied countries, although the level of price premium depends on several factors like electricity consumption. Case study of Finland and literature show that the impacts of green energy are not solely environmental. Renewable energy can benefit local public policy.Item The Impact of Optimal Demand Response Control and Thermal Energy Storage on a District Heating System(Multidisciplinary Digital Publishing Institute (MDPI), 2019-05-03) Salo, Sonja; Hast, Aira; Jokisalo, Juha; Kosonen, Risto; Syri, Sanna; Hirvonen, Janne; Martin, Kristian; Department of Mechanical Engineering; Energy efficiency and systems; Department of Mechanical EngineeringDemand response has been studied in district heating connected buildings since the rollout of smart, communicating devices has made it cost-effective to control buildings’ energy consumption externally. This research investigates optimal demand response control strategies from the district heating operator perspective. Based on earlier simulations on the building level, different case algorithms were simulated on a typical district heating system. The results show that even in the best case, heat production costs can be decreased by only 0.7%. However, by implementing hot water thermal storage in the system, demand response can become more profitable, resulting in 1.4% cost savings. It is concluded that the hot water storage tank can balance district heating peak loads for longer periods of time, which enhances the ability to use demand response strategies on a larger share of the building stock.Item Ison-Britannian energiapolitiikka ja -markkinat(2016-04-21) Syrjä, Mikke; Hast, Aira; Insinööritieteiden korkeakoulu; Alanne, KariItem Kanadan energiapolitiikka ja energiantuotanto(2015-11-26) Koikkalainen, Juha; Hast, Aira; Insinööritieteiden korkeakoulu; Alanne, KariItem Kysyntäjouston potentiaali kotitalouksissa(2015-11-26) Barsk, Aleksi; Hast, Aira; Insinööritieteiden korkeakoulu; Alanne, KariItem Maailman hiilidioksidimarkkinoiden vertailu(2014-11-28) Salo, Sonja; Hast, Aira; Insinööritieteiden korkeakoulu; Paatero, JukkaItem Oppia onnettomuuksista - ydinenergia-alan vaatimusten kehittyminen(2016-12-11) Tasa, Ida; Hast, Aira; Insinööritieteiden korkeakoulu; Alanne, KariItem Seasonal thermal energy storage for district heating(2017-09-25) Castrén, Taisia; Hast, Aira; Zakeri, Behnam; Insinööritieteiden korkeakoulu; Syri, SannaClimate change raises question of concerns about ways to reduce carbon dioxide emissions in the industrial environment, specifically in heat production. The use of waste heat from industrial facilities and renewable energy sources in district heat (DH) production helps to reduce CO2 emissions and the dependence on fossil fuels. This can be done through the integration of the thermal energy storage (TES) into the DH system. Apart from that, the combination of heat production for DH with seasonal TES (STES) increases the profitability of the co-generated heat production. The purpose of this thesis is to make a literature review for building knowledge and data-base about the different types of STES, for comparing their technical and financial fea-tures. Another aim is to model the DH system of Espoo with and without STES in the EnergyPRO -software to analyse the total costs of heat production for STES. The literature was reviewed and the technical and financial aspects of different types of STES were reported and compared with each other. The literature review showed that in recent years underground STESs (UTRES) have been actively investigated and implemented with different projects of the European Union, such as SUNSTORE, EINSTEIN and ECES Annex 12. However, the implemented UTES are incompletely reported. It is especially rare for one source to provide complete information about UTES. The DH system without and with sensible TES was modelled and in the EnergyPRO. The simulations of the TES as a short-term storage show that integrating TES into the DH sys-tem of Espoo is most profitable, when storage is a borehole TES with a volume of 150,000 m3w.e,if it is used with a heat pump (HP). The prices for the heat production in the system with TES only do not differ significantly from each other and are highest, than for the system with TES and HP. The variation of the discount rate of TES and HP annuity does not affect significantly on the heat production costs. The impact of the CO2 emissions prices on the heat production costs are considerable and made integration of TES in DH unprofitable, when emissions prices are high. The results are approximate and only show if the integration of TES into DH is profitable or not. Hereby, the hydrogeological pre-investigations of TES site and modelling of real integration of TES into the DH system with the possible HPs, buffer storage and circula-tion pumps are necessary. In addition, the investigation and modelling how TES can be integrated in the DH system as well as with additional equipment is to be done.Item Towards effective climate change mitigation: viewpoints of cost efficiency, uncertainty and consumer choice(Aalto University, 2017) Hast, Aira; Syri, Sanna, Prof., Aalto University, Department of Mechanical Engineering, Finland; Konetekniikan laitos; Department of Mechanical Engineering; Energy Efficiency and Systems; Insinööritieteiden korkeakoulu; School of Engineering; Syri, Sanna, Prof., Aalto University, Department of Mechanical Engineering, FinlandIn order to limit the concentration of greenhouse gases (GHGs) in the atmosphere and to reach the climate and energy objectives, GHG emission mitigation measures need to be implemented and the share of renewable energy increased in the energy system. In addition to policy actions, consumer energy choices also have an essential effect on the development of GHG emissions and the use of different energy sources. Furthermore, changes in consumer behavior can also be targeted in the policy instruments and the economics of consumers' energy options can be affected through policies. In this dissertation, the analyses were carried out at different levels, sectors and from different viewpoints. Policy measures necessary for meeting the national GHG emission target of Finland with least costs were studied. It was found that there are large differences in the cost-efficiency of different GHG emission mitigation measures. The risks of not meeting the predetermined GHG emission target and exceeding the estimated costs were also evaluated. The results indicate that the costs and achieved GHG emission reductions include large uncertainty, and for example the future oil price development had significant contribution to the uncertainty of GHG emission reduction costs. The progress of electricity from renewable energy sources (RES-E) in Nordic and Baltic countries was also analyzed in this thesis and the development was compared to the RES-E objectives of the countries. The analysis suggests that even if the studied countries are on track to meet their RES-E objectives, some countries are underperforming in the newer RES-E technologies. Also consumer electricity and heating choices were studied in this dissertation. The interaction between policies and consumer behavior was analyzed in particular. It was found that the voluntary green electricity products offered to consumers can include problems weakening the real additional environmental impacts of the green electricity purchase above the legally set requirements. However, especially replacing residential oil heating was one of the most cost-efficient GHG emission mitigation measures in order to meet the Finnish national GHG emission target. This study thus suggests that consumer heating choices are more likely to contribute to the policy objectives than the purchase of differentiated electricity products. It should, however, be noted that the consumer energy choices are influenced by several factors at the same time and they cannot thus be only affected by policies. In addition, the development of market prices like crude oil price can have a large impact on the economics of consumer energy options.Item Transition to carbon neutral energy systems – implications to district heating in cities(IEEE, 2018) Hast, Aira; Syri, Sanna; Welsch, Julia; Korkmaz, Pinar; Balyk, Olexandr; Department of Mechanical Engineering; Energy efficiency and systems; University of Stuttgart; Technical University of DenmarkIn this paper, the results from EU level energy system modelling with TIMES PanEU are interpreted to the city level development of the district heating (DH) systems of Warsaw and Helsinki region until 2050. In the future, there is probably more variation in the electricity prices due to the higher share of renewable energy sources in the electricity production which further affects the operation of DH systems. The results presented in this paper indicate that heat storages were almost always profitable investments and the optimal heat storage capacity was highest in 2050. The benefit of the heat storage increased with the variation in electricity prices. In Warsaw, heat pumps were also profitable. Heat production with wood and waste fuels as well as utilization of geothermal and waste heat increased in Helsinki region by 2050. In Warsaw, the consumption of biomass, waste and electricity in heat production increased by 2050.Item Tulvien ennustaminen matemaattisia malleja käyttäen(2010) Hast, Aira; Virtanen, Kai; Informaatio- ja luonnontieteiden tiedekunta; Hämäläinen, RaimoItem Utilising demand response in the future Finnish energy system with increased shares of baseload nuclear power and variable renewable energy(PERGAMON-ELSEVIER SCIENCE LTD, 2018-12) Olkkonen, Ville; Ekström, Jussi; Hast, Aira; Syri, Sanna; Department of Mechanical Engineering; Department of Electrical Engineering and Automation; Energy efficiency and systemsThe research presented in this paper aims to assess the technical effectiveness of demand response as a demand-side flexibility option to mitigate variability in the energy system in Finland in 2030. The results show that heating loads can provide a significant long-term technical potential for demand-side resource capacity. This demand-side resource capacity is not always available, as it varies according to the season and time of the day. The temporal availability of demand-side resource capacities varies between 80 and 5600 MW. Furthermore, the results show that the utilisation of demand-side resource capacity decreases significantly when the shifting time interval becomes more constrained. The utilisation of demand-side resource capacity results in balancing of residual demand in the day-ahead market, and thus more efficient utilisation of wind power generation in the Finnish power market. This smoothing effect reduces operating hours of thermal power production and the need for cross-border balancing by electricity imports during the peak hours. According to the sensitivity analysis, the ramping occurrences of district heating CHP units increase significantly with increased share of inflexible baseload nuclear power, while some of the efficiency gains can leak to the neighbouring countries.
