Interaction of DSO and local energy systems through network tariffs

One crucial factor that influences distributed energy resource investments and operation is the grid tariffs. If the price signal passed on to the consumer is not representative of the actual impact of the decentralized decisions on the power system, we may get inefficiencies. The main problem considered in this research is the interaction of a network operator and consumers to study how grid tariffs should be designed to facilitate favorable decentralized decisions. An equilibrium model based on tariffs is developed and benchmarked against a system optimization to study the effect of capacity-based and volumetric grid tariffs when the grid costs are a function of the decentralized decisions. The results show that both a volumetric and capacity-based tariff scheme provides a suboptimal outcome compared to the system optimal solution. Suboptimal decentralized decisions in the perspective of the overall power system is a result of the tariff schemes not being able to represent the actual network costs. Based on the findings, more innovative tariff schemes or related market mechanisms are needed to facilitate decentralized decisions that are aligned with the costs and benefits for the overall power system.Interaction of DSO and local energy systems through network tariffsacceptedVersio

Assessing the potential benefit of energy storage in emission constrained power markets using equilibrium modeling

An equilibrium model of the energy market is extended by a carbon emissions market. In addition, the mix of renewable energy sources is optimized given a limit on total generation. These two new features are integrated into an existing model to assess the effects of a carbon emissions market in a case study of the northern European power system. First, a fixed carbon emissions tax is deployed, revealing that carbon emissions can be greatly influenced by the availability of energy storage. Further, a carbon emission quota is implemented and the tax necessary to enforce the limit is calculated by the model. Based on the case studies, it is discussed how quota level and the availability of energy storage influence, among others, optimal system design and power market stakeholders.acceptedVersio

Nyhavna – et nullutslippsnabolag med systemsmart energiforsyning

Nyhavna er et område i Trondheim som per i dag hovedsakelig brukes til industrielle formål, men som skal utvikles til et attraktivt boligområde i de kommende tiårene. Ifølge kvalitetsprogrammet skal området ikke føre til økt energibehov, effektbehov eller klimagassutslipp i byen; og bygningene og energisystemet på Nyhavna skal samhandle med hverandre, og med omkringliggende energisystem. Siden bygningsmassen på Nyhavna vil bestå hovedsakelig av boliger, dominerer oppvarming det totale energibehovet. Hensikten med studien var da å identifisere den mest kostnadsoptimale løsningen for energisystemet, med fokus på varmeforsyning, som minimerer det totale behovet og spesielt topplastbehovet for energi levert til Nyhavna. Det studerte energiforsyningssystemet besto av et lokalt lavtemperatur-varmenett, et sesonglager for lagring av overskuddsvarme fra sommeren, en storskala varmepumpe med sjøvann som varmekilde, og strømproduksjon integrert i bygningene. I studien ble det antatt at sesonglageret hadde stor nok kapasitet til å dekke hele varmebehovet på Nyhavna. Studien viser at et energiforsyningssystem på Nyhavna basert på lokal produksjon av varme kombinert med sesonglagring er mer kostnadseffektivt enn hvis varmebehovene skulle dekkes gjennom import fra fjernvarmenettet. Det ble evaluert to scenarier for turtemperatur i det lokale varmenettet: mellom- (70 °C) og lavtemperatur (45 °C), som begge ga en betydelig reduksjon i energikostnadene. Lavtemperaturscenariet kom ut som det mest kostnadseffektive scenariet, men forskjellen mellom totale kostnader i disse to alternativene er liten, og gitt usikkerhetene i investeringskostnadene er det vanskelig å trekke en endelig konklusjon for hvilket scenario som er mest kostnadseffektivt. Lavtemperaturscenariet har noen tydelige fordeler med tanke på: (i) mer effektiv utnyttelse av sesong-lageret, slik at området kan være tilnærmet selvforsynt med oppvarming; (ii) mest effektiv drift av varmepumper, som minimerer etterspørselen etter importert elektrisitet; og (iii) mer fleksibilitet på timenivå gjennom tappevannsvarmepumpene og -tankene i bygningene. Lavtemperatursystemet er da mest i tråd med kravene til kvalitetsprogrammet, men vil imidlertid kreve mer teknisk utstyr i bygningene, noe som vil øke kompleksiteten til det lokale energisystemet. For å oppnå best mulig utnyttelse av lokale fleksibilitetsressurser, bør energisystemet på Nyhavna ha en forretningsmodell som tillater fri deling av lokalprodusert strøm innenfor området. I land som Norge med høyt behov for oppvarming, er effektiv varmeforsyning og samspill mellom strøm- og varmesystemer avgjørende for å redusere effekttopper og øke fleksibiliteten i energisystemet. Studien viser at i nullutslippsnabolag med mye lokal strømproduksjon, er varmeforsyning via et lokalt lavtemperatur-nett spesielt gunstig, da dette tillater effektiv integrasjon med strømnettet ved hjelp av varmepumper og termisk lagring. Et lavtemperatur-varmesystem muliggjør i tillegg effektiv utnyttelse av overskuddsvarmekilder, som er viktig for å redusere kostnader og utslipp fra varmeproduksjon.publishedVersio

Workflow-Based Architecture for Optimal Planning of Integrated Local Multi-Energy Systems

Integrated local multi-energy systems are recognized as a promising option to achieve the ambitious energy and climate goals set by the European Commission for 2030. The nature of integrated systems requires a sound combination of inter-disciplinary methodologies and complementary tools. Creating an efficient architecture capable of exploiting synergies between tools is therefore crucial for designing, analysing and operating integrated energy systems. The joint application of different tools needed for analysing a local system can be very demanding and time-consuming due to vastly different data structures and functionalities. To address the need for complementary tools, the aim of this paper is to establish and test an integrated modelling architecture allowing the interaction of tools into a modular toolbox for the optimal planning of integrated local multi-energy systems, and also present key preliminary outcomes.Workflow-Based Architecture for Optimal Planning of Integrated Local Multi-Energy SystemsacceptedVersio

Risk of attention-deficit hyperactivity disorder in offspring of mothers with infections during pregnancy

Background Maternal infections during pregnancy are common events that have been suggested to be risk factors for Attention-deficit hyperactivity disorder (ADHD) in offspring. Only a few studies have been conducted to date and results are conflicting. The current study investigates the associations between specific groups of prenatal maternal infections and offspring ADHD, considering timing of exposure and the role of fever. Methods We used data from the prospective Norwegian Mother, Father and Child Cohort Study (MoBa), including more than 112,000 pregnancies, linked with data from the Medical Birth Registry of Norway and the Norwegian Patient Registry to estimate odds ratios for the likelihood that children develop ADHD after being exposed to maternal infections during gestation. Results Children exposed to any maternal infection during pregnancy showed increased risk of receiving an ADHD diagnosis (OR = 1.15, CI = 1.03–1.27). Specifically, increased ADHD risk was observed after exposure to genitourinary infections in second (OR = 1.42, CI = 1.06–1.90) or third trimester (OR = 2.04, CI = 1.19–3.49), and to respiratory infections in second trimester (OR = 1.31, CI = 1.12–1.54), provided these infections were accompanied by episodes of fever. Increased ADHD risk was also observed after exposure to diarrhea without fever in the third trimester (OR = 1.25, CI = 1.07–1.46). Conclusions Overall, our results suggest that prenatal exposure to maternal infections, particularly with co-occurring episodes of fever, are risk factors for ADHD. Fever (or severity of the infection) appears to be more important in mid-pregnancy associations. Our results indicate that type of infection and timing of exposure might influence the associations, but small effect sizes require careful interpretations. The association between infection and ADHD should be estimated using discordant siblings or other negative control designs that give better adjustment for unmeasured familial confounding.publishedVersio

Early manifestations of genetic risk for neurodevelopmental disorders

Background: Attention deficit/hyperactivity disorder (ADHD), autism spectrum disorder (autism) and schizophrenia are highly heritable neurodevelopmental disorders, affecting the lives of many individuals. It is important to increase our understanding of how the polygenic risk for neurodevelopmental disorders manifests during childhood in boys and girls. Methods: Polygenic risk scores (PRS) for ADHD, autism and schizophrenia were calculated in a subsample of 15 205 children from the Norwegian Mother, Father and Child Cohort Study (MoBa). Mother-reported traits of repetitive behavior, social communication, language and motor difficulties, hyperactivity and inattention were measured in children at 6 and 18 months, 3, 5 and 8 years. Linear regression models in a multigroup framework were used to investigate associations between the three PRS and dimensional trait measures in MoBa, using sex as a grouping variable. Results: Before the age of 2, the ADHD PRS was robustly associated with hyperactivity and inattention, with increasing strength up to 8 years, and with language difficulties at age 5 and 8. The autism PRS was robustly associated with language difficulties at 18 months, motor difficulties at 36 months, and hyperactivity and inattention at 8 years. We did not identify robust associations for the schizophrenia PRS. In general, the PRS associations were similar in boys and girls. The association between ADHD PRS and hyperactivity at 18 months was, however, stronger in boys. Conclusions: Polygenic risk for autism and ADHD in the general population manifests early in childhood and broadly across behavioral measures of neurodevelopmental traits.publishedVersio

Developmental milestones in earlychildhood and genetic liability toneurodevelopmental disorders

Background: Timing of developmental milestones, such as age at first walking, is associated with later diagnoses of neurodevelopmental disorders. However, its relationship to genetic risk for neurodevelopmental disorders in the general population is unknown. Here, we investigate associations between attainment of early-life language and motor development milestones and genetic liability to autism, attention deficit hyperactivity disorder (ADHD), and schizophrenia. Methods: We use data from a genotyped sub-set (N = 25699) of children in the Norwegian Mother, Father and Child Cohort Study (MoBa). We calculate polygenic scores (PGS) for autism, ADHD, and schizophrenia and predict maternal reports of children's age at first walking, first words, and first sentences, motor delays (18 months), and language delays and a generalised measure of concerns about development (3 years). We use linear and probit regression models in a multi-group framework to test for sex differences. Results: We found that ADHD PGS were associated with earlier walking age (β = −0.033, padj < 0.001) in both males and females. Additionally, autism PGS were associated with later walking (β = 0.039, padj = 0.006) in females only. No robust associations were observed for schizophrenia PGS or between any neurodevelopmental PGS and measures of language developmental milestone attainment. Conclusions: Genetic liabilities for neurodevelopmental disorders show some specific associations with the age at which children first walk unsupported. Associations are small but robust and, in the case of autism PGS, differentiated by sex. These findings suggest that early-life motor developmental milestone attainment is associated with genetic liability to ADHD and autism in the general population

Genetic liability for schizophrenia and childhood psychopathology in the general population

Abstract Genetic liability for schizophrenia is associated with psychopathology in early life. It is not clear if these associations are time dependent during childhood, nor if they are specific across different forms of psychopathology. Using genotype and questionnaire data on children (N = 15 105) from the Norwegian Mother, Father and Child Cohort Study, we used schizophrenia polygenic risk scores to test developmental stability in associations with measures of emotional and behavioral problems between 18 months and 5 years, and domain specificity in associations with symptoms of depression, anxiety, conduct problems, oppositionality, inattention, and hyperactivity at 8 years. We then sought to identify symptom profiles—across development and domains—associated with schizophrenia polygenic liability. We found evidence for developmental stability in associations between schizophrenia polygenic risk scores and emotional and behavioral problems, with the latter being mediated specifically via the rate of change in symptoms (β slope = 0.032; 95% CI: 0.007–0.057). At age 8, associations were better explained by a model of symptom-specific polygenic effects rather than effects mediated via a general psychopathology factor or by domain-specific factors. Overall, individuals with higher schizophrenia polygenic risk scores were more likely (OR = 1.310 [95% CIs: 1.122–1.528]) to have a profile of increasing behavioral and emotional symptoms in early childhood, followed by elevated symptoms of conduct disorder, oppositionality, hyperactivity, and inattention by age 8. Schizophrenia-associated alleles are linked to specific patterns of early-life psychopathology. The associations are small, but findings of this nature can help us better understand the developmental emergence of schizophrenia

Assessing the potential benefit of energy storage in emission constrained power markets using equilibrium modeling

An equilibrium model of the energy market is extended by a carbon emissions market. In addition, the mix of renewable energy sources is optimized given a limit on total generation. These two new features are integrated into an existing model to assess the effects of a carbon emissions market in a case study of the northern European power system. First, a fixed carbon emissions tax is deployed, revealing that carbon emissions can be greatly influenced by the availability of energy storage. Further, a carbon emission quota is implemented and the tax necessary to enforce the limit is calculated by the model. Based on the case studies, it is discussed how quota level and the availability of energy storage influence, among others, optimal system design and power market stakeholders.acceptedVersio