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Effectively utilizing low-grade thermal energy is a promising approach to mitigating greenhouse gas emissions while reducing the burden on centralized power grids. Current thermoacoustic heat pumps and power generators face challenges such as high onset temperature differentials and low performance. This paper addresses these challenges by introducing a gas-liquid resonator into a thermoacoustic combined heat and power systems to recover low-grade thermal energy in residential buildings. Through Sage modeling and calculations, the internal characteristics of the proposed system and its output performance under different operating conditions are explored. At a heating temperature of 350 °C, the system can generate 6.4 kW of output thermal power, 0.9 kW of electricity, and overall exergy efficiency is 79.3 %. Combining neural network models with case studies conducted in Spain and Finland, the system can annually save 5.6 MWh and 20.7 MWh in fuel energy, reduce emissions of 1374 kg and 5180 kg of carbon dioxide, and save a total cost of €611 and €2324, respectively. Furthermore, comparisons with other emerging micro-CHP systems highlight the efficiency of the proposed system. These results indicate the high potential of thermoacoustic combined heat and power systems in recovering low-grade thermal energy and achieving energy savings and emission reductions. • Introducing an innovative thermoacoustic micro-CHP system. • Achieving an exergy efficiency of 79.3 % under standard operating conditions. • One system can annually reduce household CO 2 emissions by 5180 kg. • Ideal for households, balancing lower output levels for both heat and electricity. [ABSTRACT FROM AUTHOR]

This paper develops a two-stage model to site and size a battery energy storage system in a distribution network. The purpose of the battery energy storage system is to provide local flexibility services for the distribution system operator and frequency containment reserve for normal operation (FCR-N) for the transmission system operator. In the first stage, the priority is to fulfil the flexibility needs of the distribution system operator by managing congestions or interruptions of supply in the local network. Thus, the first stage allocates the battery to ensure reliable electricity supply in the local distribution network. The minimum required size of the battery is also determined in the first stage. The second stage optimally sizes the battery energy storage system to boost the profit by providing frequency containment reserve for normal operation. The first and second stages both solve stochastic optimization problems to design the battery energy storage system. However, the first stage considers worst-case scenarios while the second stage utilizes the most probable scenarios derived from the historical data. To validate the proposed model, real-world data from the years 2021 and 2022 in Finland are employed. The battery placement is conducted for both the IEEE 33-bus system and a Finnish case study. The profitability of the model is compared across different cases for the Finnish case study. Finally, the paper assesses the impacts of cycle aging on the battery's total profit. • A two-stage model is developed to site and size distribution-network-connected Battery Energy Storage System (BESS). • The first stage determines BESS location and minimum size for local network security. • In the second stage, the BESS profit is maximized by providing frequency containment reserve for normal operation (FCR-N). • The effects of cycle aging and the capacity fade on model profitability are analyzed. [ABSTRACT FROM AUTHOR]

This paper introduces a novel optimization approach to design and operate hybrid heating system , which integrates existing centralized district heating assets and decentralized heat pumps. Hybrid heating system enables sector coupling, where electrified heating assets can provide ancillary services for the power market. A modelling tool to study the impact on total heat delivery costs of adding heat pumps into existing district heating based heating system was developed. The case study modelling results show that decentralized assets can support a primary side of district heating network and optimal use of heating assets decreases average operating expenditure by 24%. In order to capture the full value of hybrid heating system, one needs to be able to utilize heat pumps to provide ancillary services in power market and receive compensation for feeding heat pump heat into the district heating network. The modelling results are sensitive to various parameters. Hence, a thorough sensitivity analysis is presented for the results. • Centralized and decentralized district heating assets form a hybrid heating system. • Electrified heating assets can be utilized in both heating and power markets. • Novel optimization approach for hybrid heating systems is introduced. • Use case shows that optimization decreases average operating expenditure by 24%. [ABSTRACT FROM AUTHOR]

Finland has the greatest forest cover of European countries and thus considerable raw material potential for wood pellet market development. Wood pellet production and consumption volumes in the country have increased steadily during the last decades. The aim of this paper is to present an overview of the current status of the Finnish wood pellet business and discuss the main opportunities and challenges facing future development of the industry. The paper collects and revises data on the Finnish wood pellet market based on the results of a survey of nearly 60 wood pellet experts. The results show that neglect of policy support and a lack of suitable regulation are the key factors inhibiting Finnish wood pellet industry development. Currently, wood pellets are not economically competitive with other fuels. However, Finnish wood pellet markets seem promising if challenges such as high raw material costs and competitiveness with other fuels, especially for household users, are addressed. The country has the potential to become a more important producer and consumer on European wood pellet markets if effective policy support and a suitable regulatory framework are formulated. [ABSTRACT FROM AUTHOR]

The Internet of Things can be an effective way to manage the demand side and perform demand response in thermal grids. The concept provides new models for predicting demand and gathering data in a smart and inexpensive fashion. This research investigates the deployment of room-specific demand response in a district-heated office building in Southern Finland. It is fulfilled by controlling set-point temperatures on thermostatic radiator valves. By developing a predictive algorithm on a cloud platform and gathering feedback from the environment and the users, the paper presents findings of load shifting on room level and about local discomfort. The results indicate that heating power can be increased and decreased at the thermostat, even by 104% and 47% respectively. On average, this accounts for 40 W/m2. However, the larger the set-point temperature variation is, the larger local discomfort grows. Indoor air temperature readings do not give enough evidence of thermal comfort. Hence, demand response with room-level accuracy should be deployed in areas of the building in which flexibility is least noticed. [ABSTRACT FROM AUTHOR]

Abstract Currently, the economic performance of rooftop photovoltaics (PVs) is predominantly evaluated using the levelized cost of electricity approach. Some researchers have argued that rooftop PVs should be viewed as an investment, where performance is evaluated using relevant investment analysis methods. This article argues that the proper economic value and climate mitigation potential of rooftop PVs can be assessed only if the market mechanisms and characteristics of the underlying building stock are understood better. This paper utilises a customer-driven investment model to examine the feasible market potential of rooftop PVs in an urban environment. The economic returns of PV installations are calculated for 89,000 buildings separately and by comparing them to the underlying spatial property returns, the profitability and adoption years of rooftop PVs for in different locations are estimated. Implications for CO2 emissions and the impact of the net metering (NM) policy on the rate of adoption are calculated. The results imply that even in Finland rooftop solar PVs are already profitable for a third of the residential building stock and will be profitable for a fourth of the commercial building stock by 2025. Finally, the NM could increase substantially the diffusion rate of solar PVs in the coming years. Highlights • Real estate economics provides a new perspective to estimate the diffusion of rooftop PVs. • In the Helsinki Metropolitan Area, rooftop PVs are already profitable for a third of the residential building stock. • A fourth of the commercial building stock will be profitable by 2025. • Net metering (NM) could increase the diffusion of rooftop PVs rapidly. • The benefits of implementing NM seem to outweigh the costs of implementation. [ABSTRACT FROM AUTHOR]

Abstract Major nuclear accidents are typically low-probability–high-consequence events. This paper focuses on weather and sea-level events that might affect the safety of nuclear power plants (NPPs). Flooding risks at Finnish NPP sites have been re-evaluated based on investigations of long-term changes and short-term variations in sea level, which has led to improvements in the protection against extremely high sea water level. Climate change projections indicated that 1000-year return levels of high enthalpy of the air would increase by 13–27% by 2100. However, no clear future trends were projected for the all-year-round probabilities of freezing rain at the NPP sites. Simulations of the spread of hypothetical radioactive releases during two sea-breeze cases, using weather input data at a remarkably high spatial resolution, demonstrated the impacts of coastal meteorological phenomena on atmospheric dispersion. Overviews of various single and combined weather and marine events that could possibly affect normal NPP operation highlighted the need to broaden the scope of future research. Special attention was focused on various aspects of uncertainty. According to the results, a more extreme weather or marine event corresponded to a larger uncertainty in its probability of occurrence in the changing climate. Highlights • Safe production of nuclear energy requires appraisal of weather and sea-level risks. • Changing climate affects the occurrence of extreme weather and sea-level events. • Land uplift will moderate the increase of flooding risks on the Finnish coast. • Progress in data and methods reveals new potential hazards such as meteotsunamis. • High-resolution meteorological data is vital as input for dispersion modelling. [ABSTRACT FROM AUTHOR]

The EU's energy sector depends heavily on fossil fuels, which contribute to climate change. This is why climate mitigation targets for energy production have been set, including an increased biomass use requirement. In Finland, biomass is commonly utilised but its capital, Helsinki, is still dependent on fossil fuels. With the ambition of becoming climate neutral by 2050, Helsinki is testing, inter alia, low-share wood pellet and coal co-combustion in a CHP (combined heat and power) plant. The objectives of this paper were to assess the net environmental impacts of the co-combustion and changes in urban air quality connected to pellet transport, and to identify environmental hotspots relevant to possible future higher-share co-combustion. The applied methods were screening LCA (life cycle assessment) and fine particle dispersion modelling. The results prove that low-share wood pellet co-combustion in CHP production leads to net environmental impact reductions and does not deteriorate air quality in the urban environment. If higher-share co-combustion were to be implemented, the environmental hotspots to focus on would be the operational issues of a power plant and the origin and sustainability aspects of wood pellet production. [ABSTRACT FROM AUTHOR]

Abstract: Heat pumps have rapidly gained popularity in the Nordic area, as they are marketed to provide considerable monetary savings and CO2 emission reductions. Heat pumps are installed even in buildings heated by CHP (combined heat and power production). In this paper we calculate CO2 emission factors of DH (district heating) from CHP and GSHP (ground source heat pumps) in Finland, based on hourly data at present and in various future scenarios. In LCA (life cycle assessment) analyses, usually only annual averages are used. We show that including seasonal variation can result in very different emission factors. Since during warm seasons, electricity production is significantly less carbon-intensive than in cold seasons. We find that the current emission factor of CHP DH consumption change is only 70–100 g/kWh. In the future it is 0…300 g/kWh, depending on the CO2 intensity of electricity production. The similar GSHP emission factor would develop from the present 200 g/kWh to 50…200 g/kWh. As long as electricity consumption has seasonal variation or coal condensing power is significant in the interconnected network, CHP has lower emissions than GSHP. We recommend using CLCA (consequential LCA) methodology and the inclusion of seasonal variation in heating option comparisons. [Copyright &y& Elsevier]

Energy systems are in a state of transition due to national energy and climate policies. The Finnish Government has declared a national target of achieving carbon neutrality by 2035. This will require further reductions in carbon intensity of the Finnish energy generation mix. Some of the energy related emission reductions could simultaneously be achieved through effective energy efficiency measures in the buildings sector. In this paper, the effectiveness of these measures is studied in alternative long-term energy system scenarios with varying CO 2 reduction targets for the energy supply sector until 2050. The results show that initial carbon intensity of energy mix has a significant effect on the achievable CO 2 emission reductions of demand-side measures. Moreover, assigned system boundaries can significantly affect the results, especially in a low-carbon energy system, where energy savings mostly reduce the use of wood-based biomass in the energy production. Furthermore, long-term perspective for identifying the environmental effects of an energy efficiency measure is recommended, since they often have a long economic lifetime and due to structural changes in the energy system, the marginal energy production unit changes over its lifetime. Consequently, the CO 2 emission reduction potential of an energy efficiency measure can vary over its lifetime. • Building sector demand-side measures are analysed in broader energy system context. • CO 2 emission reduction potential depends on the carbon intensity of marginal unit. • Marginal emission factor can change during the lifetime of demand-side measure. • System boundaries can significantly affect the results in a low carbon energy system. [ABSTRACT FROM AUTHOR]

Increasing reliance on uninterrupted electricity supply against emerging threats such as climate change and cyberattacks calls for higher resilience of societies against power disruptions. A better understanding of social and economic impacts during these disruptions would be important for planning of resilience improvements. However, traditional energy system models rarely include these aspects. This paper presents an integrated framework containing a geospatial power system operation model, capable of emulating system component failures and restoration according to environmental conditions, with a link to spatial social and economic values such as population, economic activity, critical services and facilities. The framework was applied for analyzing the effects of uncontrolled and controlled power outages for two windy winter weeks in Finland. This case illustrated how controlled optimization could reduce the societal costs of such outage by shifting power shortage to regions where such costs are lower and in part by shifting the costs to other factors. • Framework for linking disruptions to energy systems with socio-economic impacts. • Power system operation model with the possibility of component failures. • Illustrative case study for Finnish power system outages. • Consideration of regional, sectoral and value tradeoffs during power disruptions. [ABSTRACT FROM AUTHOR]

Finland has recently adopted a high profile in climate change mitigation. Finland has declared a national target of achieving carbon neutrality by 2035. As a part of this, the use of coal for energy purposes has been banned from year 2029 onwards. The Finnish electricity system is already very low-carbon, and more wind and nuclear power is being constructed. However, District heating (DH) is a backbone of the Finnish energy system, and it is still quite reliant on fossil fuels and domestic high-emission fuel peat, their share being 51% of DH fuels in 2018. This paper models the impacts of this transition on the electricity markets and DH systems and develops scenarios with a large-scale transition to wind and nuclear power and heat pumps in DH systems. The study finds that large-scale introduction of heat pumps would be profitable in cities Helsinki, Espoo, Turku and Vantaa, especially with the planned decrease of electricity tax. The study indicates that the impacts on Winter time capacity adequacy could be managed, but this requires considerable increases in nuclear and wind capacity. • Finland abandons hard coal use by 2029 as part of achieving carbon neutrality. • Increasing wind and nuclear power mitigates electricity price increase and capacity deficit. • Heat pumps can provide alternative to coal-CHP. • Electricity distribution fee and tax limit economic potential of heat pumps. [ABSTRACT FROM AUTHOR]