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2
Content available remote Fotowoltaika w teorii i praktyce
EN
The aim of the study was to conduct an economic analysis of the possibilities of using photovoltaic (PV) installations in selected farms. Two selected online PV calculators were used for the analysis. The research included 15 farms located in the Małopolskie Province. For a PV installation estimated using Calculator 1, Hewalex, the payback period ranged from 5.5 to 7 years for the 40% subsidy option and from 9 to 11 years without the subsidy, respectively. On the other hand, the payback period estimated with the use of the SmartekDom calculator ranged from 6 to 8 years for the option with 40% subsidy. However, without the subsidy, the period ranged from 7 to even 13 years.
PL
Celem pracy była analiza ekonomiczna dotycząca możliwości wykorzystania instalacji fotowoltaicznej w wybranych gospodarstwach rolnych. Analiza została wykonana z wykorzystaniem wybranych dwóch kalkulatorów internetowych PV. Zakres pracy obejmował badania w 15 gospodarstwach położonych na terenie województwa małopolskiego. Okres zwrotu inwestycji w instalację fotowoltaiczną oszacowany z wykorzystaniem kalkulatora 1 - Hewalex wynosił od 5,5 roku do 7 lat dla wariantu z dofinansowaniem 40%. Bez dofinansowania odpowiednio od 9 do 11 lat. Natomiast okres zwrotu inwestycji oszacowany z wykorzystaniem kalkulatora 2 - SmartekDom wynosił od 6 lat do 8 lat dla wariantu z dofinansowaniem 40%. Natomiast bez dofinansowania to okres od 7 do nawet 13 lat.
4
Content available remote Relationship between selected percentiles and return periods of extreme events
EN
This paper investigates the relationship between selected percentiles, return periods and the concepts of rare and extreme events in climate and hydrological series, considering both regular and irregular datasets, and discusses the IPCC and WMO indications. IPCC (Annex II: Glossary. Contribution of Working Groups I, II and III to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change. IPCC, Geneva, 2014) establishes that an extreme event should be rare and exceed selected upper and lower thresholds (10th and 90th percentiles); WMO (Guidelines on the defnition and monitoring of extreme weather and climate events-TT-DEWCE WMO 4/14/2016. World Meteorological Organization, Geneva, 2016) suggests thresholds near the ends of the range, but leaves them undetermined. The concept of “rare” relates the extreme events to the time domain and is typically expressed in terms of return period (RP). The key is to fnd the combination between “rare”, percentile and return period. In particular, two crucial items are analysed: (1) how the return period may vary in response to the choice of the threshold, in particular when it is expressed in terms of percentiles; (2) how the choice of producing a regular or irregular dataset may afect the yearly frequency and the related return periods. Some weather variables (e.g. temperature) are regular and recorded at fxed time intervals, while other phenomena (e.g. tornadoes) occur at times. Precipitation may be considered either regular, all-days being characterized by a precipitation amount from 0 (no precipitation) to the top of the range, or irregular (rainy-days only) considering a precipitation day over a selected instrumental or percentile threshold. These two modes of interpreting precipitation include a diferent number of events per year (365 or less) and generate diferent return periods. Every climatic information may be afected by this defnition. The 90th percentile applied to observations with daily frequency produces 10-day return period and the percentiles necessary to get 1 year, 10 years or other return periods are calculated. The general case of events with selected or variable frequencies, and selected percentiles, is also considered with an example of a precipitation series, two-century long.
EN
Flood is becoming an intensive hydro-climatic issue at the Kelantan River basin in Malaysia. Univariate frequency analysis would be unreliable due to multidimensional behaviour of food, which often demands multivariate fow exceedance probabilities. The joint distribution analysis of multiple interacting food characteristics, i.e. food peak, volume and duration, is very useful for understanding critical hydrologic behaviour at a river basin scale. In this paper, a copula-based methodology is incorporated for multivariate food frequency analysis for the 50-year annual basis food characteristics of Kelantan River basin at Guillemard bridge station in Malaysia. Investigation reveals that the Lognormal (2P), Johnson SB-4P and Gamma-3P are selected as marginal distributions for the food peak fow, volume and duration series. Several bivariate families such as mono-parametric, bi-parametric (i.e. mixed version) and rotated version of Archimedean copulas and also the elliptical copula are introduced to cover a large dependence pattern of food characteristics. The dependence parameter of bivariate copulas is estimated by the method of moments (MOM) based on the inversion of Kendall’s tau and maximum pseudo-likelihood estimator. To analytically validate and recognize most parsimonious copulas, GOF test and Cramer–von Mises distance statistics (Sn) with the parametric bootstrap method are employed. The Gaussian copula is identifed as the most justifable model for joint modelling of the food peak–volume and peak–duration combination for MOM-based parameter estimation procedure. Similarly, the Frank copula is selected as the best-ftted structure for modelling peak–duration combination based on MPL estimators, but the MOM estimator recognized Gaussian copula as most suitable for peak–volume pair. Furthermore, the best-ftted copulas are used for obtaining the joint and conditional return periods of the food characteristics
7
Content available remote Evaluating the energy and cost benefits of heat pumps in multi-occupancy dwellings
EN
This paper provides a tabular analysis of an “outdoor air-water” heat pump in heating and domestic hot water system inside a multi-occupancy dwelling house. The study set out to compare a conventional system using the city’s district heat supply with one using an “outdoor air-water” heat pump. One part of the analysis is the energy performance of the renewable energy source. The study is also addressed the benefits of saving on conventional heat source and the period of financial return on the heat pump investment.
PL
W artykule opracowano tabelaryczną analizę systemu ogrzewania i ciepłej wody użytkowej w domu wielorodzinnym, z zastosowaniem pompy ciepła „woda-powietrze”. Badania przeprowadzono dla porównania konwencjonalnego miejskiego systemu ogrzewania z systemem pompy ciepła „woda-powietrze”. Jedną z części analizy jest charakterystyka energetyczna źródła energii odnawialnej. Analizy przedstawiają korzyści z oszczędzania przy zastosowaniu konwencjonalnego źródła ciepła oraz okres zwrotu finansowego z inwestycji w pompę ciepła.
8
Content available remote Kolektory słoneczne jako alternatywne źródło energii
PL
W pracy przedstawiono analizę kosztów stosowania pompy ciepła do ogrzewania obiektu ogrodniczego. W oparciu o aktualne koszty inwestycyjne określono minimalną wartość kosztów ciepła przy której, przy arbitralnie założonym okresie użytkowania pompy zwracają się zwiększone nakłady finansowe poniesione na stosowanie biwalentnego systemu grzewczego. Określono również koszty związane z opłatami z tytułu użytkowania środowiska przyrodniczego. Przeanalizowano ponadto wpływ powierzchni obiektu na okres zwrotu poniesionych nakładów na montaż w systemie grzewczym pompy ciepła.
EN
In the paper the analysis of costs, connected with using a heat pump for heating a horticultural object is presented. Basing on the current investment costs, we have determined the minimum value of the heat costs at which, with an arbitrarily assumed pump using period, the increased outlays made for using the bivalent heating system will pay back. The costs connected with charges for using the natural environment have also been determined. In addition, the effect of the object area on the payback period, considering the outlays on assembling heat pumps in the heating system, has been analyzed.
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