Renewable Energy Resource Assessment and Forecasting

In recent years, several projects and studies have been launched towards the development and use of new methodologies, in order to assess, monitor, and support clean forms of energy. Accurate estimation of the available energy potential is of primary importance, but is not always easy to achieve. The present Special Issue on ‘Renewable Energy Resource Assessment and Forecasting’ aims to provide a holistic approach to the above issues, by presenting multidisciplinary methodologies and tools that are able to support research projects and meet today’s technical, socio-economic, and decision-making needs. In particular, research papers, reviews, and case studies on the following subjects are presented: wind, wave and solar energy; biofuels; resource assessment of combined renewable energy forms; numerical models for renewable energy forecasting; integrated forecasted systems; energy for buildings; sustainable development; resource analysis tools and statistical models; extreme value analysis and forecasting for renewable energy resources

Hydrodynamic modelling of the microbial water quality in a drinking water source as input for risk reduction management

To mitigate the faecal contamination of drinking water sources and, consequently, to prevent waterborne disease outbreaks, an estimation of the contribution from different sources to the total faecal contamination at the raw water intake of a drinking water treatment plant is needed. The aim of this article was to estimate how much different sources contributed to the faecal contamination at the water intake in a drinking water source, Lake Rådasjön in Sweden. For this purpose, the fate and transport of faecal indicator Escherichia coli within Lake Rådasjön were simulated by a three-dimensional hydrodynamic model. The calibrated hydrodynamic model described the measured data on vertical temperature distribution in the lake well (the Pearson correlation coefficient was 0.99). The data on the E. coli load from the identified contamination sources were gathered and the fate and transport of E. coli released from these sources within the lake were simulated using the developed hydrodynamic model, taking the decay of the E. coli into account. The obtained modelling results were compared to the observed E. coli concentrations at the water intake. The results illustrated that the sources that contributed the most to the faecal contamination at the water intake in Lake Rådasjön were the discharges from the on-site sewers and the main inflow to the lake – the river Mölndalsån. Based on the modelling results recommendations for water producers were formulated. The study demonstrated that this modelling approach is a useful tool for estimating the contribution from different sources to the faecal contamination at the water intake of a drinking water treatment plant and provided decision-support information for the reduction of risks posed to the drinking water source

The effect of wave response motion on the insolation on offshore photovoltaic installations

Offshore photovoltaic energy is possibly the most important future step in the harnessing of solar energy. Since no long-term offshore photovoltaic installation exists to date, various unknowns are still present, creating a research gap. For instance, floating structures will have some type of response to incoming waves. This response is highly dependent on the design of the floating structure. This response will have some effect on the insolation on offshore photovoltaic systems installed on floating structures. This research presents a simulation tool that would allow an offshore system designer to assess this effect in order to minimize it and thus, optimize the energy yield of the system. Furthermore, this simulation tool was verified with an experimental setup simulating sinusoidal wave responses and the results are presented in this research. Finally, a parametric analysis was performed taking days close to the 21st of each month of the year for photovoltaic installations facing south with fixed inclinations of 30 ° and 5 ° This research will improve the design of offshore floating platforms used for photovoltaic installations.peer-reviewe

Water quality modelling: microbial risks associated with manure on pasture and arable land

While agricultural activities, such as the application of manure on arable land and animal grazing on pastures, provide economic and environmental benefits, they may also pose microbial risks to water sources. The aim of this paper was to study the microbial fate and transport in an agricultural catchment and recipient water source through further development of the hydrological model HYPE. Hydrological modelling was combined with hydrodynamic modelling to simulate the fate and transport of Salmonella spp., verotoxin-producing Escherichia coli O157:H7 and Cryptosporidium parvum in an agricultural catchment of a drinking water source, Lake Vombsj\uf6n, in Sweden. This approach was useful to study the influence of different processes on the pathogen fate and transport, and to interpret the relative changes in the simulated concentrations. Sensitivity analysis indicated that the largest uncertainties in the model were associated with the estimation of pathogen loads, parameterisation of the pathogen processes, and simulation of partitioning between surface runoff and infiltration. The proposed modelling approach is valuable for assessing the relative effect of different risk-reducing interventions

METRIC-GIS: An advanced energy balance model for computing crop evapotranspiration in a GIS environment

A novel ArcGIS toolbox that applies the Mapping Evapotranspiration with Internalized Calibration model was developed and tested in a semi-arid environment. The tool, named METRIC-GIS, facilitates the pre-processing operations and the automatic identification of potential calibration and pixels review. The energy balance components obtained from METRIC-GIS were contrasted with those from the original METRIC version (R2 = 1; RMSE = 0 W m–2 or mm day–1 for ETc) Additionally, an irrigated scheme located at southern Spain was considered for assessing Kc variability in the maize fields with METRIC-GIS. The identified spatial variability was mainly due to differences in irrigation regimes, crop management practices, and planting and harvesting dates. This information is critical for developing irrigation advisory strategies that contribute to the area sustainability. The developed tool facilitates data input introduction and reduces computational time by up to 50%, providing a more user-friendly alternative to other existing platforms that use METRIC

Sensitivity Analysis on Mapping EvapoTranspiration at High Resolution Using Internal Calibration (METRIC)

Mapping EvapoTranspiration at high Resolution using Internal Calibration (METRIC) is most widely used to quantify evapotranspiration (ET) spatially and temporally. It is essential to inspect the model’s response to errors in various parameters used in the model. Landsat 5 images from May 30 2009, July 1 2009 and a Landsat 7 image from September 27 2009 are used in this study. Fourteen different fields composed of Corn, Soybeans, Alfalfa are randomly chosen for each crop type. Two kinds of errors are addressed in this study. One, with the errors that are transferred and potentially compensated by calibration (Global error) and the other is the error that is not passed into the calibration (Local error). For global error, Reflectance at the satellite (ρ), transmissivity (τ), surface temperature (Ts), wind speed (u), Reference Evapotranspiration (ETr) are chosen. In addition, the sensitivity towards selection of hot and cold pixels is also investigated. For local errors, albedo (α), surface temperature (Ts), momentum roughness length (Zom), soil heat flux (G), difference between air and surface temperature (dT) are considered. In this study, we have found that METRIC is able to compensate most of the global errors passed through the calibration to give consistent results, when the variables considered above has changed to their extremes. ETr should be estimated at a good degree of accuracy to maintain the METRIC’s results to be realistic. Also, selection of hot and cold pixels is the most crucial and sensitive process in METRIC. In case of local errors: Zom is relatively insensitive to the model. dT is found to be the most sensitive variable for bare soils. However, the other parameters are linearly proportional to their errors. Adviser: Ayse Irma

Hydrodynamic and Microbiological Modelling of Water Quality in Drinking Water Sources

Faecal contamination of drinking water sources poses risks for waterborne disease outbreaks. To manage these risks the fate and transport of faecal contamination in a drinking water source need to be understood and quantitatively described. In this study the fate and transport of faecal contamination in a drinking water source, Lake Rådasjön in Sweden, was simulated using a coupled hydrodynamic and microbiological modelling approach. To calibrate the microbiological model that describes the inactivation of faecal indicators as a function of temperature and sunlight, a microcosm experiment was performed. The experiment consisted of three outdoor microcosm trials performed in March, August and November 2010 to capture seasonal variations in the inactivation of faecal indicators. The indicators studied in the microcosm experiment included traditional faecal indicators (total coliforms, E. coli, enterococci, somatic coliphages) and Bacteroidales genetic markers (BacH and BacR) that can be used in microbial source tracking to determine the human or ruminant origin of faecal contamination. The spread of faecal contamination in the lake was simulated using E. coli and Bacteroidales genetic markers. The results indicated that hydrometeorological conditions such as wind, inflow to the lake and temperature stratification of the lake have a major impact on the spread of faecal contamination. The simulations showed that faecal contamination from the river Mölndalsån, emergency sewer overflow and on-site sewers can pose threats to the drinking water supply of the cities of Gothenburg and Mölndal. Moreover, modelling the fate and transport of Bacteroidales markers in a water body provided information about the contribution of different sources to the total concentration of these markers at the water intake. This can substantially improve the usefulness of Bacteroidales markers in microbial source tracking

ANALYZING ECOHYDROLOGY OF SUBIRRIGATED MEADOW, DRY VALLEY AND UPLAND DUNE ECOSYSTEMS USING REMOTE SENSING AND IN-SITU ESTIMATIONS IN THE SEMIARID SAND HILLS REGION OF NEBRASKA, USA

Nebraska’s dependence upon the High Plains (Ogallala) Aquifer for agricultural production is vital to the state’s economy, ecology and hydrology. The Sand Hills region (58,000 km2) of Nebraska is a unique system of lakes, (~5%) wetlands, (~10%) subirrigated meadows, (~20%) dry valleys and (~65%) upland sand dune ecosystems. Understanding how each of these land cover types reacts to climate conditions of different water limitations is vital to regional water resource management. This research explores the ecohydrological behavior of different land cover types at the Gudmundsen Sand Hills Research Laboratory (GSRL) near Whitman, Nebraska in the heart of the Sand Hills region of Nebraska by using remote sensing and in-situ estimations of energy partitioning. By employing satellite technology and micrometeorological instrumentation this research establishes a better understanding how energy partitioning, and resulting evapotranspiration (ET), differs between different vegetative communities. We present findings of diurnal and seasonal estimates of energy partitioning as well as daily estimations of ET from both satellite image processing and in-situ observations by Bowen ratio energy balance systems (BREBS). This research also employed different techniques to estimate energy partitioning via remote sensing by adjusting radiation, wind speed, and stability parameters to better represent areas with high topographic relief. The last focal point of this research was to analyze how energy partitioning and ET varied both spatially and temporally under different climate conditions between 2004 (normal year), 2006 (dry year), and 2009 (wet year). Adviser: John D. Lenter

Simulating the Oil Spill in the Arabian Gulf Marine Environment: A Risk Assessment in Association with UAE Coastal Desalination Plants

The current study is directed towards the development of oil spill hazard contour maps for the prediction of oil spill travel times and critical wind directions in association with major strategic desalination plants in United Arab Emirates. Five desalination plants in are selected along the UAE coastline to be the potential destination points of oil spill hazards. These plants are AI-Shuwayhat, AI-Mirfa, Umm AINar & Taweelah, Jebel Ali and AI-Layah. In order to reach the set target, a coastal hydraulics simulation model is employed to adopt the real sea-state dynamic conditions. The hydrodynamic simulated results are tuned and tested against actual documented measurements of tides and currents. The simulated flow pattern of the surface currents produced by the model is also compared with common cited patterns. Oil spill simulation is then conducted employing the resolved flow field and other hydrodynamic results. The oil spill model parameters are tested to verify their sensitivity for final model setup. A validation of the model performance is also carried out utilizing well documented actual observations of oil spill incidents in the Arabian Gulf. At that stage, the coupled hydrodynamic and oil spill model are set to perform a series of simulations on hypothetical oil spills based on extreme case conditions. The study area is divided into zones covering the oil export loading terminals and the oil tanker routs. The shortest traveling times of the oil spill from various zones to each desalination plant are identified in association with the critical wind directing the oil slick to that plant. At last, the simulated travel times and critical wind directions are used to produce hazard contour maps for shortest arrival times and critical wind directions for the five selected desalination plants