Optimal Capacities of Distributed Renewable Heat Supply in a Residential Area Connected to District Heating

In this paper, residential area of 16 buildings with average annual 5.6 GWh heat consumption is studied in terms of distributed renewable energy supply with gradual separation from the local district heating network. Optimal heat supply and heat production capacities in the area are estimated by using hourly linear optimisation model for two separate model years and for normal and low district heating temperature cases. Results indicate that disintegration from district heating supply inflict 12-24% higher annualised total costs. However, completely removing the areal district heating network increases total costs considerably. Solution for heat supply in building area is a package consisting of ground source heat pump, heat storage and photovoltaics panel. Centralised ground source heat pump with centralised heat storage completes the heat supply cost-efficiently with low district heating supply levels. Solar collectors and exhaust air heat pumps are not cost-efficient solutions due to high investment costs

Dynamically distributed district heating for an existing system

The study in hand introduces the concept of dynamically distributed district heating. The concept addresses the challenges related to transforming an existing 3rd generation district heating system into a 4th generation system, one area at a time. It enables a cost-efficient option for introducing low-temperature distribution and new distributed heat supply while preserving the advantages of an efficient, more centralised system. The concept includes new large-scale heat storage capacity in areas on the outskirts of the network or within otherwise suitable locations, charged during summer when low-cost heat is commonly available. These areas also have new distributed heat supply. The areas are run in an island-mode during the heating season, i.e. disconnected from the main system. The study presents a preliminary analysis of the concept using Helsinki district heating system as a case study based on open data on district heating demand, building stock data and optimisation modelling of the district heating system for assessing the heat supply costs

Dynamically distributed district heating for an existing system

The study in hand introduces the concept of dynamically distributed district heating. The concept addresses the challenges related to transforming an existing 3rd generation district heating system into a 4th generation system, one area at a time. It enables a cost-efficient option for introducing low-temperature distribution and new distributed heat supply while preserving the advantages of an efficient, more centralised system. The concept includes new large-scale heat storage capacity in areas on the outskirts of the network or within otherwise suitable locations, charged during summer when low-cost heat is commonly available. These areas also have new distributed heat supply. The areas are run in an island-mode during the heating season, i.e. disconnected from the main system. The study presents a preliminary analysis of the concept using Helsinki district heating system as a case study based on open data on district heating demand, building stock data and optimisation modelling of the district heating system for assessing the heat supply costs

Effect of language experience on selective auditory attention: An event-related potential study

Dual language experience has typically been shown to improve various executive control functions. We investigated with event-related brain potentials (ERPs) recorded from early (natively) bilingual speakers and control participants whether it also affects auditory selective attention. We delivered to our participants two tone streams, one to the left and one to the right ear. Both streams consisted of standard tones and two types of infrequent deviant tones which had either an enhanced duration or intensity. The participants were instructed to attend either to the right or left stream and to detect longer-duration deviants in the attended stream. The results showed that the early bilinguals did not outperform the controls in target detection accuracy or speed. However, the late portion of the attention-related ERP modulation (the negative difference, Nd) was larger over the left hemisphere in the early bilinguals than in the controls, suggesting that the maintenance of selective attention or further processing of selectively attended sounds is enhanced in the bilinguals. Moreover, the late reorienting negativity (RON) in response to intensity-deviant tones was larger in the bilinguals, suggesting more efficient disengagement of attention from distracting auditory events. Hence, our results demonstrate that brain responses associated with certain aspects of auditory attention are enhanced in the bilingual adults, indicating that early dual language exposure modulates the neuronal responsiveness of auditory modality.Peer reviewe