Abstract

This research presents a bottom-up methodology for assessing biogas potentials applied in a local community in Croatia. The research is based on analysing the flow of resources on a local level and capability of local actors to innovate and cooperate. Our method grades the local actors – in this case, owners of family farms in Gundinci municipality in Croatia – based on their farms’ biogas potential (or the amount and quality of manure they produce) and an indicator which we refer to as innovative-cooperation capacity. This methodology builds upon the biogas potential analysis by identifying farmers who are willing to improve their farms manure management system and cooperate in the field of biogas production in Gundinci. The replication of this methodology could stimulate rural development, through pinpointing realizable biogas projects, which could generate new money flows for the local economies and help farmers meet the norms of the European Union Nitrates Directive which regulates manure management, in order to control nitrogen flows in agriculture.

Abstract

Buyuk Melen Watershed provides drinking water from the Western Black Sea region to Istanbul province, which Buyuk and Kucuk Melen rivers, Asar, Ugur and Aksu rivers. Many settlement areas, fertilized agricultural lands, industrial plants and solid/liquid waste dumping areas have present in Melen watershed, causing substantial pollution problems. Melen watershed has been at a serious risk of pollution that a lot of settlement areas, agricultural lands, industrial facilities, and solid and liquid waste. In this study, LANDSAT satellite data was used to monitor the status of this area on the potential of the region studied. In the watershed change of 1987, 2001, 2006 and 2010 and also supported by satellite data. However, contaminants in the watershed discharges to the inner parts as shown from the satellite data have also been observed that the increase in pollution.

Abstract

The emissions of carbon dioxide and nitrogen and sulphur oxides for electricity generation with coal and biomass co-firing are investigated and the furnace gas temperature assessed. The study uses simulation and considers fuel combinations based on two coals (bituminous coal, lignite) and four types of biomass (rice husk, sawdust, chicken litter, refused derived fuel). With increasing biomass, net CO2 emissions are seen to decline significantly for all types of selected biomass, while gross carbon dioxide emissions increase for all blends except bituminous coal/refuse derived fuel, lignite/chicken litter and lignite/refuse derived fuel. The reductions in emissions of nitrogen and sulphur oxides are dependent on the contents of nitrogen and sulphur in the biomass. The results also show for all fuel combinations that increasing the biomass proportion decreases the furnace exit gas temperature.

Abstract

In this article, to assess the use of renewable energy sources, the method of social efficiency of substituting non-renewable fuels with renewable energy sources was used. Social efficiency means the difference of energy-environmental, economic or sociological effects connected with producing the same amount of usable product in conditions of applying reference fuel and renewable substitute energy source. The amount of useful product should equal the use of one substitute energy unit. The proposed method constitutes a generalization of the existing method of economic effect evaluation on the basis of the Economic Efficiency of Energy Substitution indicators (EEES). Furthermore, the relations of calculations which enable defining dimensionless indexes for the effects of interest and method of standardization of the social efficiency index were described. The procedure is applied for the evaluation of renewable energy sources (solar energy in solar collectors, boilers powered by biofuels and heat pumps using geothermal energy) to prepare hot tap water.

Abstract

In this paper is described the developing of an integrated electricity supply–demand, gaseous emission and air pollution model for study of possible baseline electricity developments and available options to mitigate emissions. This model is constructed in STELLA software, which makes use of Systems Dynamics Modeling as the methodology.

Several baseline scenarios have been developed from this model and a set of options of possible developments of Kosovo's Electricity Supply–Demand and Gaseous Emissions are investigated. The analysis of various scenarios results in medium growth scenarios (MGS) that imply building of generation capacities and increase in participation of the electricity generation from renewable sources. MGS would be 10% of the total electricity generation and ensure sustainable development of the electricity sector. At the same time, by implementation of new technologies, this would be accompanied by reduced GHG (CO₂ and NO_x) emissions by 60% and significant reduction for air pollutants (dust and SO₂) by 40% compared to the business-as-usual (BAU) case. Conclusively, obtained results show that building of new generation capacities by introducing new technologies and orientation on environmentally friendly energy sources can ensure sustainable development of the electricity sector in Kosovo.  

Abstract

Trigeneration systems are potentially more energetically and economically efficient than cogeneration systems due to possibility to extend operation at nominal load. However, these systems also face challenges of future development characterised by reduced heating and cooling demands, as a consequence of implementation energy efficiency measures, and fluctuating electricity prices, as a consequence of increased penetration of intermittent renewable energy sources. The main objective of the paper is to research the operation strategies of trigeneration systems and to derive the optimal ones. The model proposed in this paper consists of two different systems, a conventional system and a trigeneration system. The heating, refrigerating and electric loads are known. The price of gas is constant while electricity prices are fluctuating at hourly basis. The optimization method is based on two criteria – energy and economic, which were applied hierarchically. Therefore, two optimal operation strategies are introduced. A mixed integer non-linear programming model provides energy and cost savings up to 32% and 28% respectively in comparison with conventional system. In addition, optimal capacity of trigeneration system is explored.

Abstract

Hybridisation of district heating systems can contribute to more efficient heat generation through cogeneration power plants or through an increase in the share of renewable energy sources in total energy consumption while reducing negative aspects of particular energy source utilisation. In this work, the performance of a hybrid district energy system for a small town in Croatia has been analysed. A mathematical model for process analysis and optimisation algorithm for optimal system configuration have been developed and described. The main goal of the system optimisation is to reduce heat production costs. Several energy sources for heat production have been considered in 8 different simulation cases. Simulation results show that the heat production costs could be reduced with introduction of different energy systems into an existing district heating system. Renewable energy based district heating systems could contribute to heat production costs decrease in district heating systems up to 30% in comparison with highly efficient heat production technologies based on conventional fuels.

Abstract

Because of the rapid growth of energy demand in developing countries, policies for energy efficiency are receiving increasing attention. Although Energy Efficiency Standards and Labeling (EES&L) is a standard policy tool in many countries, some developing countries, such as Lao PDR, have not yet implemented them fully. In order to understand the potential impact of EES&L, this paper aims at collecting data that contribute to EES&L and at analysing appliance possessions in Vientiane City, Lao PDR. We conducted an interview survey on 600 households in Vientiane City and performed logistic regression analysis that set possession of appliances as the dependent variable. As a result of the analysis, we identified that the income level and the electricity consumption are the principal independent variables and the relationship of these variables with possession rates depends on appliances. Our model helps identify appliances that are expected to be in high demand associated with either economic growth or human population increase in Vientiane City.

Abstract

Thermoelectric modules produce electricity from heat flow. In areas without electricity, biomass is generally burnt in open fires or rudimentary stoves in order to generate heat, to cook and to produce domestic hot water. Combustion quality in these devices is very low and needs a large amount of wood extracted from surrounding forests. “Planete Bois” develops highly efficient clean multifunction stoves based on double chamber combustion. As an exhaust fan is necessary to adjust the primary and secondary air flows for optimal combustion, these stoves cannot currently be used without electricity. Thermoelectric modules incorporated in a heat exchanger between the flue and the hot water tank can supply the exhaust fan and also produce some electricity for other basic purposes. Our paper presents tests that were done on one of these stoves to size the thermoelectric generator and thus the produced electricity. These preliminary tests are used to identify an outlook for the successful implementation of these stoves.

Abstract

The performance of a plug-flow automated aerobic digester used with the compost of the Biodegradable Organic Waste (BOW) from a typical family at its generation rhythm was evaluated. During a 13 month assessment, 179.7 kg of BOW were treated and 106.7 kg of compost were obtained with a C:N ratio of 12 and an average concentration of N of about 2.72%. Additional tests enabled to assess the generation of stable and good quality compost according to the considered standards, suitable for using as organic fertilizer and other uses, such as biotreatments. The design, location and operational characteristics of the device have determined reduced leachate emissions, the absence of unpleasant odour generation and incidence of insects or other vectors, implying the viability of their use without affecting the user´s life quality. It could be an efficient alternative treatment for household BOW, from a technical, economic, energy, cultural and environmental point of view, easy to implement for users lacking in special training.

Abstract

Public Private Partnership initiatives and models are proven, scalable and internationally-recognized procurement methods for reducing the operating costs and improve environmental quality of public bodies. However, there are still barriers to overcome. Local communities’ engagement, lack of technical knowledge and financing constraints are just some topics that still need reliable solutions. The governance model that is adopted for the “Chieti Towards 2020” Project, which was funded under the European Local Energy Assistance in the 2012-2014 period, try to operate a "glocal" synthesis between local instances and global issues. A mixed bottom-to-top and top-to-bottom approach involves local communities’ trying to address requirements through centralized, high-level management and coordination activities. To date, the most relevant Project outcomes consist of 87 municipalities involved, a structured database of energy audit and data about 144 buildings and about 46,000 public light points. Moreover, an effective engagement of public and private stakeholders lays the foundation for a strong Energy Performance Contract framework able to leverage financing based on minimum guaranteed energy savings of 20% in respect to baseline values.

Abstract

A groundwater flow model was developed to simulate groundwater extraction from the public water supply source of the City of Kikinda. The hydrodynamic model includes the municipal groundwater source of Kikinda (Šumice and the Jezero Well), but also an extended area where there are groundwater sources that provide water supply to three factories: (MSK, TM and LŽT - Kikinda). Hydrodynamic modeling, based on the numerical method of finite differences will show the groundwater balance of the sources in the extended area of Kikinda. The impact of the industrial water sources on the regime of the public water supply source will also be assessed. The radius of influence of the groundwater source is determined by simulating the travel of conservative particles over a period of 200 days.

Abstract

This paper assesses through scenario analysis the future role of bioenergy in a deep mitigation context. We focus in particular on the implications for sustainability – namely, competing demands for land-use, import dependency, availability of sustainable bioenergy and economics. The analysis here is limited to one Member State, Ireland, which is an interesting case study for a number of reasons, including significant import dependency and recent acceleration in renewable energy deployment. We used the Irish TIMES model, the energy systems model for Ireland developed with the TIMES model generator, for this scenario analysis. Long term, least cost mitigation scenarios point to bioenergy meeting more than half of Ireland’s energy needs by 2050. The results of this paper point to the impact of tightened sustainability criteria and limitation on bioenergy imports, namely the increased use of indigenous bioenergy feedstocks, increased electrification in the energy system, the introduction of hydrogen and higher marginal abatement costs.

Abstract

This paper focuses on urban passenger transport eco-efficiency, which can be defined as the production of maximum benefits to society while minimising environmental impacts from urban transport’s inputs of energy and materials. Researchers have intensively studied transport’s varied environmental impacts, particularly through Life Cycle Assessment; this paper argues that primary transport energy per capita is presently the best measure of impact. Although transport’s societal benefits have generally been regarded as self-evident, access to out-of-home activities, not passenger-km, should be considered as the fundamental useful output of an urban transport system, since transport is a derived demand. We argue that access levels are roughly similar in all high-income OECD cities, so that these cities can be ranked on transport eco-efficiency simply on the basis of per capita primary transport energy.

Abstract

The Croatian electricity demand exceeds domestic production and about 30% of additional power is covered from imports. The Croatian government is planning to add domestic production capacity, using natural gas and coal as the main fuel. Due to the attractive solar irradiation in Croatia, these new projects offer the possibility to build these thermal power plants as hybrid plants by adding solar energy within the production. The present paper will investigate the potential of solar energy in the Southern Croatian region and its possible contribution in a hybrid set-up. The paper assesses the required input data and presents a hybrid Concentrated Solar Power (CSP) design. The results demonstrate the potential of adding a CSP in a hybrid power plant in Southern Croatia.

Abstract

The power generation sector is expected to undergo substantial changes in Hungary in the near future due to the decommissioning of several large units reaching the end of their lifetimes in parallel to the projected increase of renewable electricity generating capacity. In addition to the traditionally widely used deterministic adequacy assessment methods, a probabilistic approach has a great importance in case of technologies with different capacity credits. An analytical country-specific adequacy assessment model enabling the probabilistic modelling of wind power plants was developed and applied to generating capacity forecasts for Hungary. Model parameters were estimated using multi-annual production, plant availability and hourly system demand data. Adequacy indicators obtained from the model clearly show increasing reliance on imported electricity in the absence of investments in new generating capacity.

Abstract

This paper considers the transient stability enhancement of a power system containing large amounts of solar and wind generation in Japan. Following the Fukushima Daiichi nuclear disaster there has been an increasing awareness on the importance of a distributed architecture, based mainly on renewable generation, for the Japanese power system. Also, the targets of CO2 emissions can now be approached without heavily depending on nuclear generation. Large amounts of renewable generation leads to a reduction in the total inertia of the system because renewable generators are connected to the grid by power converters, and transient stability becomes a significant issue. Simulation results show that sodium-sulfur batteries can keep the system in operation and stable after strong transient disturbances, especially for an isolated system. The results also show how the reduction of the inertia in the system can be mitigated by exploiting the kinetic energy of wind turbines.

Abstract

Solar power and wind are the most promising distributed energy sources. The photovoltaic system has attracted significant attention in recent years. Although their benefits are numerous, they are known to create power quality issues, because of the power electronic converters they use. This paper investigates if there is a possibility to improve power quality only by connecting a solar photovoltaic system to the grid, and then gives results of on-site power quality measurements in the grid before and after the connection of the solar photovoltaic system.

Abstract

Thermo-Ecological Cost with the inclusion of Life Cycle (TEC-LC) is defined as the cumulative exergy consumption of non-renewable natural resources associated with any product and its life cycle, taking into account the necessity to prevent and compensate losses caused by depletion of natural resources and the release of harmful substances into the environment. The problem of collecting data for solving TEC-LC equations is not the only one which can be faced in determining this indicator. The selection of the calculation method could also affect obtained results due to the accuracy of the selected algorithm. Numerical stability is particularly important in the case of large sets of data and in this case operations on large matrixes. The issue with a set of TEC-LC balanced equations is examined and compared on the basis of heat exchanger components.

Abstract

In Paris (France), urban projects currently cover 10% of the territory. In the context of rising energy costs and the fight against climate change, reducing energy consumption in buildings and transportation is an unavoidable issue for these urban projects. While many studies analyse assessment tools and sustainability frameworks, only a few focus on developer practices. We describe how energy issues are integrated into urban development, focusing on three projects located in Paris. We compare environmental specifications made within these three projects to ensure high energy quality of the planned buildings. We observed that the way of prescribing energy performances varies from project to project. Differences in priorities from one engineering firm to another lead to a high variability of parameters identified to ensure high building energy performances.