Hybrid Power Station Research Articles

Impact of renewable energies – environmental and economic aspects

Purpose – The purpose of this paper is to provide an immediate image about the reality of the renewable energies as experienced by an Algerian company.Design/methodology/approach – The adopted approach focused on assessment of renewable energies’ impact (especially the thermal solar power) on the environment and on the economic aspect of an Algerian company.Findings – The perception of environmental dimension is highlighted by means of an evaluation study supported by the calculation of quantities of CO2 emitted by two power stations (the new hybrid power station of Hassi R’mel (SPPI) and a conventional one (Sonelgaz)).Research limitations/implications – This research has limitations that the authors plan to study in perspective: assessing the impact of wind systems on the environmental and economic aspects.Practical implications – The analysis of obtained results shows and puts emphasis on the importance of renewable energies, especially thermal solar power, by identifying and evaluating the environmenta...

Minimum long-term cost solution for remote telecommunication stations on the basis of photovoltaic-based hybrid power systems

In the case of the telecommunication (T/C) services' expansion to rural and remote areas, the market generally responds with the minimum investments required. Considering the existing situation, cost-effective operation of the T/C infrastructure installed in these regions (i.e. remote T/C stations) becomes critical. However, since in most cases grid-connection is not feasible, the up-to-now electrification solution for remote T/C stations is based on the operation of costly, oil consuming and heavy polluting diesel engines. Instead, the use of photovoltaic (PV)-based hybrid power stations is currently examined, using as a case study a representative remote T/C station of the Greek territory. In this context, the present study is concentrated on the detailed cost-benefit analysis of the proposed solution. More precisely, the main part of the analysis is devoted to develop a complete electricity production cost model, accordingly applied for numerous oil consumption and service period scenarios. Note that in all cases examined, zero load rejections is a prerequisite while minimum long-term cost solutions designated are favorably compared with the diesel-only solution. Finally, a sensitivity analysis, demonstrating the impact of the main economic parameters on the energy production cost of optimum sized PV-diesel hybrid power stations, is also provided.

A Wind-Hydro-Pumped Storage Station Leading to High RES Penetration in the Autonomous Island System of Ikaria

Pumped storage is generally viewed as the most promising technology to increase renewable energy source penetration levels in power systems and particularly in small autonomous island grids, where technical limitations are imposed by the conventional generating units. The Hybrid Power Station (HPS) of Ikaria Island, Greece, which is currently in the construction stage, will be one of the first wind-hydro-pumped-storage hybrid stations in the world. In this paper, the HPS is described and a suitable operating policy is introduced, both for the HPS and the overall generation system of Ikaria, taking into consideration the existing regulatory framework for HPS in isolated island grids. Based on the proposed policy, the operation of the Ikaria Island system is simulated on an annual basis, in order to quantify the expected benefits from the operation of the HPS.

Optimum hybrid photovoltaic-based solution for remote telecommunication stations

The vast growth of the mobile telecommunication (T/C) sector during the recent years has led to the extension of the respective networks even to the most remote areas. Many of these areas, however, often lack electricity grid supply and as a result installation of energy autonomous T/C stations, usually based on diesel-oil electricity generation, is essential. On the other hand, technological developments and considerable procurement cost reduction of photovoltaics (PVs) encourage also the use of PV stand-alone configurations, as an alternative energy solution for the operation of these remote T/C stations. Instead of using PV-battery configurations alone, contribution of a diesel engine in terms of moderate fuel consumption may downsize the system and improve its economic performance. In this context, an optimum sizing methodology currently developed is used to determine the dimensions of such an autonomous hybrid system, based on the criterion of minimum initial cost. The developed methodology is accordingly applied to a representative Greek area of high solar potential under different scenarios of fuel consumption and panels’ tilt angle. From the results obtained, the proposed hybrid power station appears to be one of the most attractive energy solutions for the support of remote T/C stations, providing increased levels of reliability and presenting low maintenance needs.

Fuel and Greenhouse Gas Emission Reduction Potentials by Appropriate Fuel Switching and Technology Improvement in the Canadian Electricity Generation Sector

Problem statement: In recent years, Greenhouse Gas (GHG) emissions and their potential effects on global climate change have been a worldwide concern. According to International Energy Agency (IEA), power generation contributes more than half of the global GHG emissions. Approach: Purpose of this study is to examine GHG emission reduction potentials in the Canadian electricity generation sector through fuel switching and adoption of advanced power generation systems. To achieve this objective, eight different scenarios were introduced. In the first scenario, existing power stations’ fuel was switched to natural gas. Existing power plants were replaced by Natural Gas Combined Cycle (NGCC), Integrated Gasification Combined Cycle (IGCC), Solid Oxide Fuel Cell (SOFC), hybrid SOFC and SOFC-IGCC hybrid power stations in scenario numbers 2 to 6, respectively. In last two scenarios, CO2 capture systems were installed in the existing power plants and in the second scenario, respectively. Results: The results showed that Canada’s GHG emissions can be reduced by 33, 59, 20, 64, 69, 29, 86 and 94% based on the first to eighth scenarios, respectively. On the other hand, the second scenario is the most practical and its technology has already matured and is available. In this scenario by replacing existing power plants by NGCC power plants, Canada can fulfill more than 25% of its 238,000 kt year-1 commitment of GHG emission reduction to the Kyoto Protocol. In addition, the GHG emission reduction potentials for each province and Canada as a whole were presented and compared. Based on the results, Alberta, Ontario and Saskatchewan are the biggest producers of GHG in Canada by emitting 49, 21 and 14% of Canada’s GHG emissions, respectively. Therefore, they have higher potential to reduce GHG emissions. The comparison of the results for different provinces revealed that based on efficiency of electricity generation and consumed fuel distribution; specific scenario(s) tend to be suitable for each province. Conclusion: The results pointed out that despite of acceptable performance of some provinces, there are still great potentials to reduce GHG emission level in Canada. In addition, the economical analysis showed that some scenarios are economically competitive with current technologies and should be considered when a new power station is to be built.

Greenhouse gas emissions of fossil fuel-fired power plants: current status and reduction potentials, case study of Iran and Canada

In this paper, methodology to estimate GHG emissions from electricity generation sector using Iran as an example was first explained. Then different scenarios to reduce GHG emissions were evaluated for two countries: Canada and Iran. The results demonstrated that there were great potentials for GHG emission reduction in both countries. These potentials were evaluated by introducing eight different scenarios, including power stations' fuel switching to natural gas, replacement of existing power plants with natural gas combined cycle, Integrated Gasification Combined Cycle (IGCC), Solid Oxide Fuel Cell (SOFC), hybrid SOFC, and SOFC-IGCC hybrid power stations, and installation of CO2 capture systems.

Operating policies for wind-pumped storage hybrid power stations in island grids

Pumped storage is today viewed as the most suitable storage technology for achieving high wind penetration levels in multi-megawatt-sized autonomous island grids, where the technical constraints introduced by the conventional generating units impose limitations on the output of wind farms. In this study, an operating policy is proposed for hybrid wind-hydro power stations (HPSs) in island grids, to increase wind penetration levels, while at the same time minimising the impact on the conventional generation system and ensuring the viability of the HPS investment. The proposed operating strategy is applied to three different autonomous island systems using a dedicated logistic model, to evaluate the effect of the HPS on the overall operation and economics of the island systems and to assess the feasibility of HPS investments.

Calculating the efficiency of a hybrid power station employing a high-temperature fuel cell

We present equations for calculating the efficiency of a hybrid power station that consists of an electrochemical generator constructed on the basis of high-temperature fuel cells and a gas turbine. The equations were used to analyze the effect the density of current through the fuel cells and the fuel utilization ratio in them have on certain technical characteristics of the hybrid power station.

Using hydropower to complement wind energy: a hybrid system to provide firm power

This paper presents a theoretical study of how wind power can be complemented by hydropower. A conceptual framework is provided for a hybrid power station that produces constant power output without the intermittent fluctuations inherent when using wind power. Two hypothetical facilities are considered as case studies. One of them is a hydropower plant located on the “Presidente Benito Juarez” dam in Jalapa del Marques, Oaxaca, Mexico. The other hypothetical facility is a wind farm located near “La Venta”, an area in Juchitan, Oaxaca, Mexico. The wind–hydro-power system is a combined wind and hydro power plant in a region that is rich in both resources. The model shows that the hybrid plant could provide close to 20 MW of firm power to the electrical distribution system. On a techno-economic basis, we obtain the levelized production cost of the hybrid system. Taking into account two different discount rates of 7% and 10%, figures for levelized production cost are developed.

Appropriate renewable hybrid power systems for the remote aboriginal communities

Renewable power supply systems have been a natural choice for many of Australia’s small remote aboriginal communities where the costs of diesel fuel are high. The results have been mixed. This is partially due to design factors, but more importantly due to community acceptance of these technologically complex systems and the maintenance arrangements with the community power station operators and local resource agencies. This paper looks at some of the issues to consider in the selection, design, installation and maintenance of appropriate hybrid power stations for smaller remote aboriginal communities.

Combining design and operational knowledge to enhance generator plant diagnostics

An approach to the construction of an intelligent system for performing generator plant diagnosis in which a model of diagnostic expertise is constructed prior to actual system development is considered. The use of the expertise of both plant designers and operators has allowed an enhanced model of generator plant diagnostics to be constructed which can identify a fault from a set of observed symptoms in addition to predicting the likely operational impact of the identified fault. This will assist the operator in making better decisions when under severe time pressure. Furthermore, it will allow the operator to assess an appropriate course of remedial actions. The paper discusses the features of design and operational knowledge and how these can be used to derive enhanced diagnostics. A methodology for creating the model of diagnostic expertise is then described. Once the model has been constructed an intelligent system can be developed. An architecture for such an intelligent system is discussed in the paper. An advantage of the modelling approach is that it allows flexibility in the actual implementation. The use of a number of potential intelligent system technologies for implementing the system is discussed. A hybrid power station implementation is described which utilises many intelligent system technologies to further extend the decision support available to operators.