50 research outputs found
Pohjoismaisten sähkömarkkinoiden integraatio - Suunnitellut siirtoverkkoinvestoinnit
AALTO-YLIOPISTON KAUPPAKORKEAKOULU TIIVISTELMÄ
Taloustieteen pro gradu -tutkielma 17.12.2012
Sami Rinne
Tiivistelmä:
Pohjoismaisten sähkömarkkinoiden integraatio – Suunnitellut siirtoverkkoinvestoinnit
Pohjoismaat muodostavat hyvin yhtenäisen ja tehokkaan alueellisen sähkömarkkinan.
Lähivuosikymmeninä tapahtuva Euroopan laajuinen ja laajamittainen siirtyminen
hiilidioksidineutraaliin sähköntuotantoon edellyttää kuitenkin pohjoismaisten sähkönsiirtoyhteyksien
merkittävää lisävahvistamista.
Tässä työssä kartoitetaan investointisuunnitelmat uusista sähkönsiirtoyhteyksistä
Pohjoismaissa sekä Pohjoismaiden ja niiden naapurimaiden välillä. Lisäksi selvitetään,
millä perusteilla kyseiset suunnitelmat on valittu toteutettaviksi ja miten suunnitelmissa
on huomioitu investoijan kannalta optimaalisten verkkoinvestointien talousteoria.
Lisäksi selvitään julkaistujen investointisuunnitelmien perusteella sekä omin
laskelmin, minkälaisia ovat suunniteltujen verkkoinvestointien vaikutukset sähkön
hintaan sekä tuottajien ja kuluttajien ylijäämiin Pohjoismaissa.
Sähkönsiirtokapasiteettia suunnitellaan lisättävän Pohjoismaista erityisesti Saksaan,
mutta myös Hollantiin, Baltian maihin ja Yhdistyneeseen kuningaskuntaan. Investointien
päävaikuttimia ovat markkinaintegraatio, uusien energiantuotantoyksiköiden (erityisesti
tuulivoima) yhdistäminen sähköverkkoon sekä sähkön toimitusvarmuuden
parantaminen. Kantaverkkoyhtiöt eivät investointeja suunnitellessaan pyri voittojensa
maksimointiin, kuten tapahtuisi yksityisesti toteutettavissa verkkoinvestoinneissa.
Suunniteltujen verkkoinvestointien toteutuessa pohjoismainen sähkön hinta nousee
lähemmäs Saksan hintaa. Siirtoyhteyksien lisäämisen on arvioitu pienentävän merkittävästi
sähkön tuotantokustannuksia sekä kasvattavan kokonaismarkkinahyötyä. Kokonaismarkkinahyödyn
kasvu johtuu tuottajien ylijäämän huomattavasta kasvusta,
sillä samaan aikaan kuluttajien ylijäämä ja kantaverkkoyhtiöiden keräämät pullonkaulatulot
vähenevät. Alueellisten sähkönhintaerojen tasaantuessa yksityisesti toteutettavat
verkkoinvestoinnit muuttuvat vähemmän houkutteleviksi.
Avainsanat: Pohjoismaat, sähkömarkkinat, siirtoverkko, investoinnit, pullonkaula
Nurmirehu päihittää viljan edullisuudessa
Nurmisäilörehu on suomalaisten nautojen ruokinnan perusta. Säilörehun tuotantokustannusta pidetään yleensä huomattavasti rehuviljan kauppahintaa korkeampana. Tämän vuoksi yleisessä keskustelussa on esitetty huolestuneita puheenvuoroja väkirehuruokinnan lisääntymisen vaaroista.vo
Is forest management a significant source of monoterpenes into the boreal atmosphere?
Peer reviewe
Measurements of hydrocarbon emissions from a boreal fen using the REA technique
Fluxes of biogenic volatile organic compounds (VOC) and methane were measured above a boreal fen. Vegetation on the fen is dominated by Sphagnum mosses and sedges. A relaxed eddy accumulation (REA) system with dynamic deadband was designed and constructed for the measurements. Methane, C-2-C-6 hydrocarbons and some halogenated hydrocarbons were analysed from the samples by gas chromatographs equipped with FID and ECD. A significant flux of isoprene and methane was detected during the growing seasons. Isoprene emission was found to follow the common isoprene emission algorithm. Average standard emission potential of isoprene was 680 mu g m(-2) h(-1). Fluxes of other non-methane hydrocarbons were below detection limit.Fluxes of biogenic volatile organic compounds (VOC) and methane were measured above a boreal fen. Vegetation on the fen is dominated by Sphagnum mosses and sedges. A relaxed eddy accumulation (REA) system with dynamic deadband was designed and constructed for the measurements. Methane, C-2-C-6 hydrocarbons and some halogenated hydrocarbons were analysed from the samples by gas chromatographs equipped with FID and ECD. A significant flux of isoprene and methane was detected during the growing seasons. Isoprene emission was found to follow the common isoprene emission algorithm. Average standard emission potential of isoprene was 680 mu g m(-2) h(-1). Fluxes of other non-methane hydrocarbons were below detection limit.Fluxes of biogenic volatile organic compounds (VOC) and methane were measured above a boreal fen. Vegetation on the fen is dominated by Sphagnum mosses and sedges. A relaxed eddy accumulation (REA) system with dynamic deadband was designed and constructed for the measurements. Methane, C-2-C-6 hydrocarbons and some halogenated hydrocarbons were analysed from the samples by gas chromatographs equipped with FID and ECD. A significant flux of isoprene and methane was detected during the growing seasons. Isoprene emission was found to follow the common isoprene emission algorithm. Average standard emission potential of isoprene was 680 mu g m(-2) h(-1). Fluxes of other non-methane hydrocarbons were below detection limit.Peer reviewe
Temporal Variation of Ecosystem Scale Methane Emission From a Boreal Fen in Relation to Temperature, Water Table Position, and Carbon Dioxide Fluxes
We have analyzed decade-long methane flux data set from a boreal fen, Siikaneva, together with data on environmental parameters and carbon dioxide exchange. The methane flux showed seasonal cycle but no systematic diel cycle. The highest fluxes were observed in July-August with average value of 73 nmol m(-2) s(-1). Wintertime fluxes were small but positive, with January-March average of 6.7 nmol m(-2) s(-1). Daily average methane emission correlated best with peat temperatures at 20-35 cm depths. The second highest correlation was with gross primary production (GPP). The best correspondence between emission algorithm and measured fluxes was found for a variable-slope generalized linear model (r(2) = 0.89) with peat temperature at 35 cm depth and GPP as explanatory variables, slopes varying between years. The homogeneity of slope approach indicated that seasonal variation explained 79% of the sum of squares variation of daily average methane emission, the interannual variation in explanatory factors 7.0%, functional change 5.3%, and random variation 9.1%. Significant correlation between interannual variability of growing season methane emission and that of GPP indicates that on interannual time scales GPP controls methane emission variability, crucially for development of process-based methane emission models. Annual methane emission ranged from 6.0 to 14 gC m(-2) and was 2.7 +/- 0.4% of annual GPP. Over 10-year period methane emission was 18% of net ecosystem exchange as carbon. The weak relation of methane emission to water table position indicates that space-to-time analogy, used to extrapolate spatial chamber data in time, may not be applicable in seasonal time scales.Peer reviewe
Mountain birch : potentially large source of sesquiterpenes into high latitude atmosphere
Emissions of volatile organic compounds (VOCs) from mountain birches were measured in Abisko, northern Sweden. Mountain birches make up the majority of the tree biomass in Scandinavian high latitudes, a region subject to significant climate warming. The measurements were carried out in two growing seasons. The emissions of four branches, each from a different individual tree, were measured in June-August 2006 and one of them again in July 2007. The measurements were conducted using a dynamic flow through chamber covered with Teflon film. The studied mountain birches were found to emit substantial amounts of linalool, monoterpenes and sesquiterpenes. The monoterpene emission was dominated by sabinene. The magnitude and composition of the sesquiterpene emission changed dramatically between the years. For example, the average alpha-farnesene emission potential in 2006 was almost 2600 ng g(dw)(-1) h(-1) (3.5 pmol g(dw)(-1) s(-1)) while in 2007 alpha-farnesene was not detected at all. Also the emissions of other sesquiterpenes decreased in 2007 to a fraction of that in 2006. One possible explanation for the change in emissions is the herbivory damage that occurred in the area in 2004. Herbivory is known to enhance the emissions of sesquiterpenes, especially those of alpha-farnesene, and the effect may last for several years.Emissions of volatile organic compounds (VOCs) from mountain birches were measured in Abisko, northern Sweden. Mountain birches make up the majority of the tree biomass in Scandinavian high latitudes, a region subject to significant climate warming. The measurements were carried out in two growing seasons. The emissions of four branches, each from a different individual tree, were measured in June-August 2006 and one of them again in July 2007. The measurements were conducted using a dynamic flow through chamber covered with Teflon film. The studied mountain birches were found to emit substantial amounts of linalool, monoterpenes and sesquiterpenes. The monoterpene emission was dominated by sabinene. The magnitude and composition of the sesquiterpene emission changed dramatically between the years. For example, the average alpha-farnesene emission potential in 2006 was almost 2600 ng g(dw)(-1) h(-1) (3.5 pmol g(dw)(-1) s(-1)) while in 2007 alpha-farnesene was not detected at all. Also the emissions of other sesquiterpenes decreased in 2007 to a fraction of that in 2006. One possible explanation for the change in emissions is the herbivory damage that occurred in the area in 2004. Herbivory is known to enhance the emissions of sesquiterpenes, especially those of alpha-farnesene, and the effect may last for several years.Emissions of volatile organic compounds (VOCs) from mountain birches were measured in Abisko, northern Sweden. Mountain birches make up the majority of the tree biomass in Scandinavian high latitudes, a region subject to significant climate warming. The measurements were carried out in two growing seasons. The emissions of four branches, each from a different individual tree, were measured in June-August 2006 and one of them again in July 2007. The measurements were conducted using a dynamic flow through chamber covered with Teflon film. The studied mountain birches were found to emit substantial amounts of linalool, monoterpenes and sesquiterpenes. The monoterpene emission was dominated by sabinene. The magnitude and composition of the sesquiterpene emission changed dramatically between the years. For example, the average alpha-farnesene emission potential in 2006 was almost 2600 ng g(dw)(-1) h(-1) (3.5 pmol g(dw)(-1) s(-1)) while in 2007 alpha-farnesene was not detected at all. Also the emissions of other sesquiterpenes decreased in 2007 to a fraction of that in 2006. One possible explanation for the change in emissions is the herbivory damage that occurred in the area in 2004. Herbivory is known to enhance the emissions of sesquiterpenes, especially those of alpha-farnesene, and the effect may last for several years.Peer reviewe
Temporal Trends in Healthcare Costs and Outcome Following ICU Admission After Traumatic Brain Injury
Objective: To assess temporal trends in 1-year healthcare costs and outcome of intensive care for traumatic brain injury in Finland. Design: Retrospective observational cohort study. Setting: Multicenter study including four tertiary ICUs. Patients: Three thousand fifty-one adult patients (>= 18 yr) with significant traumatic brain injury treated in a tertiary ICU during 2003-2013. Intervention: None. Measurements and Main Results: Total 1-year healthcare costs included the index hospitalization costs, rehabilitation unit costs, and social security reimbursements. All costs are reported as 2013 U.S. dollars (39,809 (95% CI, 41,473) per patient. Adjusted healthcare costs decreased only in the Glasgow Coma Scale 13-15 and 65 years and older subgroups, due to lower rehabilitation costs. Adjusted 1-year mortality did not change in any subgroup (p <0.05 for all subgroups). Adjusted risk of permanent disability decreased significantly in all subgroups (p <0.05). Conclusion: During the last decade, healthcare costs of ICU-admitted traumatic brain injury patients have remained largely the same in Finland. No change in mortality was noted, but the risk for permanent disability decreased significantly. Thus, our results suggest that cost-effectiveness of traumatic brain injury care has improved during the past decade in Finland.Peer reviewe
Familial idiopathic normal pressure hydrocephalus
Idiopathic normal pressure hydrocephalus (iNPH) is a late-onset surgically alleviated, progressive disease. We characterize a potential familial subgroup of iNPH in a nation-wide Finnish cohort of 375 shunt-operated iNPH-patients. The patients were questionnaired and phone-interviewed, whether they have relatives with either diagnosed iNPH or disease-related symptomatology. Then pedigrees of all families with more than one iNPH-case were drawn. Eighteen patients (4.8%) from 12 separate pedigrees had at least one shunt-operated relative whereas 42 patients (11%) had relatives with two or more triad symptoms. According to multivariate logistic regression analysis, familial iNPH-patients had up to 3-fold risk of clinical dementia compared to sporadic iNPH patients. This risk was independent from diagnosed Alzheimer's disease and APOE epsilon 4 genotype. This study describes a familial entity of iNPH offering a novel approach to discover the potential genetic characteristics of iNPH. Discovered pedigrees offer an intriguing opportunity to conduct longitudinal studies targeting potential preclinical signs of iNPH. (C) 2016 Elsevier B.V. All rights reserved.Peer reviewe
Diabetes is associated with familial idiopathic normal pressure hydrocephalus : a case-control comparison with family members
Background The pathophysiological basis of idiopathic normal pressure hydrocephalus (iNPH) is still unclear. Previous studies have shown a familial aggregation and a potential heritability when it comes to iNPH. Our aim was to conduct a novel case-controlled comparison between familial iNPH (fNPH) patients and their elderly relatives, involving multiple different families. Methods Questionnaires and phone interviews were used for collecting the data and categorising the iNPH patients into the familial (fNPH) and the sporadic groups. Identical questionnaires were sent to the relatives of the potential fNPH patients. Venous blood samples were collected for genetic studies. The disease histories of the probable fNPH patients (n = 60) were compared with their >= 60-year-old relatives with no iNPH (n = 49). A modified Charlson Comorbidity Index (CCI) was used to measure the overall disease burden. Fisher's exact test (two-tailed), the Mann-Whitney U test (two-tailed) and a multivariate binary logistic regression analysis were used to perform the statistical analyses. Results Diabetes (32% vs. 14%, p = 0.043), arterial hypertension (65.0% vs. 43%, p = 0.033), cardiac insufficiency (16% vs. 2%, p = 0.020) and depressive symptoms (32% vs. 8%, p = 0.004) were overrepresented among the probable fNPH patients compared to their non-iNPH relatives. In the age-adjusted multivariate logistic regression analysis, diabetes remained independently associated with fNPH (OR = 3.8, 95% CI 1.1-12.9, p = 0.030). Conclusions Diabetes is associated with fNPH and a possible risk factor for fNPH. Diabetes could contribute to the pathogenesis of iNPH/fNPH, which motivates to further prospective and gene-environmental studies to decipher the disease modelling of iNPH/fNPH.Peer reviewe