Development modes analysis of renewable energy power generation in North Africa

North African countries generally have strategic demands for energy transformation and sustainable development. Renewable energy development is important to achieve this goal. Considering three typical types of renewable energies— wind, photovoltaic (PV), and concentrating solar power (CSP)—an optimal planning model is established to minimize construction costs and power curtailment losses. The levelized cost of electricity is used as an index for assessing economic feasibility. In this study, wind and PV, wind / PV / CSP, and transnational interconnection modes are designed for Morocco, Egypt, and Tunisia. The installed capacities of renewable energy power generation are planned through the time sequence production simulation method for each country. The results show that renewable energy combined with power generation, including the CSP mode, can improve reliability of the power supply and reduce the power curtailment rate. The transnational interconnection mode can help realize mutual benefits of renewable energy power, while the apportionment of electricity prices and trading mechanisms are very important and are related to economic feasibility; thus, this mode is important for the future development of renewable energy in North Africa.     

CO2 emission and avoidance in mobile applications

The present paper analyzes the CO₂ emissions from mobile communications and portable wireless electronic devices in the Korea environment. The quantitative and qualitative contributions to CO₂ emission reduction of the substitution of renewable energy for traditional electricity as the power supply in these devices are also investigated.Firstly, the national CO₂ emission coefficient is temporarily estimated as 0.504 tCO₂/MWh, which can be regarded as the basis for calculating CO₂ emissions in mobile devices. The total annual CO₂ emissions from mobile devices is calculated as approximately 1.4 million tons, comprising 0.3 million tCO₂ for portable wireless electronic devices and 1.1 million tCO₂ for electric equipment required for mobile communication service.If renewable energy sources are substituted for traditional electricity sources in the supply for mobile devices, solar cell and wind turbine systems can reduce CO₂ emissions by about 87% and 97%, respectively. However, the use of fuel cell systems will only slightly reduce the CO₂ emissions. However, the use of the direct methanol fuel cell system can release 8% more CO₂ emissions than that emitted by using traditional electricity sources.     

Assessment of renewable energy reserves in Taiwan

Since Taiwan imports more than 99% of energy supply from foreign countries, energy security has always been the first priority for government to formulate energy policy. The development of renewable energy not only contributes to the independence of energy supply, but also achieves benefits of economic development and environmental protection. Based upon information available to public, the present paper reassesses reserves of various renewable energies in Taiwan. The assessment includes seven kinds of renewable energies, namely, solar energy, wind power, biomass energy, wave energy, tidal energy, geothermal energy and hydropower, which are all commercialized and matured in terms of current technologies. Other renewable energies, which have not proven as matured as the aforementioned ones, are only assessed preliminarily in this paper, such as second generation of biomass, deep geothermal energy, the Kuroshio power generation and ocean thermal energy conversion.According to the estimation of this paper, the reserve of wind energy, up to 29.9 kWh/d/p (i.e., kWh per day per person), is the largest one among seven kinds of renewable energies in Taiwan, followed by 24.27 kWh/d/p of solar energy, 4.55 kWh/d/p of biomass, 4.58 kWh/d/p of ocean energy, 0.67 kWh/d/p of geothermal energy and 16.79 kWh/d/p of hydropower. If regarding biomass as a primary energy, and assuming 40% being the average efficiency to convert primary energy into electricity, the total power of the seven kinds of renewable energy reserves is about 78.03 kWh/d/p, which is equal to 2.75 times of 28.35 kWh/d/p of national power generation in 2008. If the reserves of 54.93 kWh/d/p estimated from other four kinds of renewable energies that have not technically matured yet are also taken into account, it will result that the reserves of renewable energy in Taiwan can be quite abundant.Although the results of the assessment point out that Taiwan has abundant renewable energy resources, the four inherent shortcomings – low energy density, high cost of power generation, instability of power supply, and current cost of renewable energy being still higher than that of fossil energy – have to be overcome first, before renewable energy is actually formed as a main component in national energy mix. The measures executed by government to break through these barriers further include the upgrade of the technological level, the formulation of the necessary policies, and the work together from all levels for the overall promotion.     

Power quality analysis of wind farm connected to Alaçatı substation in Turkey

This paper presents simulation results and power quality measurements of a wind farm. The wound rotor induction generator at 600 kW is employed for power conversion in the wind energy conversion system (WECS). This induction machine is connected to the drive circuit via rotor terminals and speed control is carried out by means of chopper circuit. The model used in the package program is experimentally tested on the single machine drive system at 3.5 kW in the laboratory, after which the power quality issues of the wind farm are investigated by using the same model for 12 wind turbines in PSCAD.     

MODERGIS application: Integrated simulation platform to promote and develop renewable sustainable energy plans,Colombian case study

This research presents the MODERGIS Integrated Simulation's Platform as a tool to promote and develop renewable energy plans under sustainability criteria, in order to increment the participation of renewable technologies in the national “energy mix” and shows an application to Colombia as a case study. Potential zones of solar and wind energy and productive areas were determined for bio-energies, by means of a geographical information system which simulated energy scenarios influenced by climatic phenomena up to the year 2030. Results yield potentials of 26,600 MW in wind energy and 350,000 MW in solar energy. Bioenergy potentiates in a sustainable way of 366,310 km per biomass, 291,486 km in African palm, 9,667 km in sugar cane. These scenarios were simulated in a supply/demand with time horizons up until 2030, including an analysis of the effects on the energy systems of the El Niño Southern Oscillation atmospheric component (ENSO). Finally, in order to obtain an appropriate mix of renewable sources that could be introduced in the national energy mix, the Multi-Criteria Analysis method VIKOR was used, allowing to perform performing 5151 possible combinations of renewable projects; the optimal selection corresponds to 600 MW from wind power, 740 MW solar photovoltaic and 660 MW solar thermoelectric. Giving these results to the new scene allowed for incrementing the participation of renewable technologies up to a 0.23% in the current year and up to a 7% of the “energy mix” in the year 2030.     

Economic evaluation of hybrid renewable energy systems for rural electrification in Iran—A case study

The Binalood region in Iran enjoys an average wind speed of 6.82 m/s at 40 m elevation and an average daily solar radiation of 4.79 kWh/m²/day. Within this perspective, a remote rural village in Binalood region, called Sheikh Abolhassan, can readily be expected to have more than enough potential for its load demand to be supplied with a stand-alone hybrid renewable energy system. Yet the local state-run electrical service provider extended the utility grid to the village in 2006 to boost the already present diesel generator. This study aims, firstly, to explore how economical it would have been to keep supplying the electricity of the village by the diesel generator and add renewable energy generators to increase the renewable fraction of the system. On a second stage, we tried to investigate how renewable energy sources (RESs) can still be added to the current utility grid power supply in Sheikh Abolhassan to achieve a more economical and environmentally friendly system. The software HOMER is used in this study to evaluate the feasibility of various hybrid diesel-RES and grid-RES energy systems. Findings indicated that the addition of renewable power generators to the system both before and after the grid extension could and still can result in a more economical power system, which is obviously cleaner and more climate-benign.     

Assessment of renewable energy resources potential for electricity generation in Bangladesh

Renewable energy encompasses a broad range of energy resources. Bangladesh is known to have a good potential for renewable energy, but so far no systematic study has been done to quantify this potential for power generation. This paper estimates the potential of renewable energy resources for power generation in Bangladesh from the viewpoint of different promising available technologies. Estimation of the potential of solar energy in Bangladesh is done using a GIS-based GeoSpatial Toolkit (GsT), Hybrid System Optimization Model for Electric Renewables (HOMER) model and NASA Surface Meteorology and Solar Energy (SSE) solar radiation data. The potential of wind energy is estimated by developing a Bangladesh wind map using NASA SSE wind data and HOMER model. A review of country's biomass and hydro potential for electricity generation is presented. The technical potential of gird-connected solar PV is estimated at 50,174 MW. Assuming that 1000 h per year of full power is the feasible threshold for the exploitation of wind energy, the areas that satisfy this condition in the country would be sufficient for the installation of 4614 MW of wind power. The potential of biomass-based and small hydro power plants is estimated at 566 and 125 MW, respectively. The renewable energy resources cannot serve as alternative to conventional energy resources, yet they may serve to supplement the long-term energy needs of Bangladesh to a significant level.     

An assessment on the planning and construction of an island renewable energy system – A case study of Kinmen Island

During the last 50 years, Kinmen's economy has gone from military-based to increasingly tourism-based, Kinmen has been putting various constructions into action, and hence, the demand for electricity supply is getting higher relatively while the province is pushing various constructions. Nowadays, Kinmen County Government has made directions for future developments already and kept on promoting the sustainable development of Kinmen Island in order to make it a suitable place for living. According to the development blueprint, the future resident population will increase to around 150 ～ 200 thousand people so the relative electricity consumption in Kinmen Island will cause serious problems for Taipower in addition to large scale environmental pollution. The present study researches on both the limitation and independence of this particular island and presumes the electricity power supply will be provided through renewable energy sources, such as solar energy, wind energy, and tidal power generation and so on, whereby it will achieve the target of energy saving and carbon reduction successfully soon. Upon the construction process of the renewable energy sources, this study will simultaneously assess the eco-environment and social conditions on the island to evaluate the feasibility of existing renewable energy technologies which are more mature and determine the optimum renewable energy system that shall be constructed in the Kinmen region in the near future, in order to replace traditional energy sources. Meanwhile, it will assist the related energy industries to create an ultra-clean environment in Kinmen with self-developing power and enhance international competition forces so as to establish a positive international image of environmental protection by achieving a habitat with energy self-sufficiency, and ultimately the empirical model can be duplicated and promoted to other islands.     

Contribution of renewable energy sources to electricity production in the La Rioja Autonomous Community,Spain. A review

The implementation of the emissions market should imbue renewable energies with a greater degree of competitiveness regarding conventional generation. In order to comply with the Kyoto protocol, utilities are going to begin to factor in the cost of CO₂ (environmental costs) in their overall generating costs, whereby there will be an increase in the marginal prices of the electricity pool.This article reviews the progress made in the La Rioja Autonomous Community (LRAC) in terms of the introduction of renewable energy technologies since 1996, where renewable energy represents approximately only 10% of the final energy consumption of the LRAC. Nonetheless, the expected exploitation of renewable energies and the recent implementation of a combined cycle facility mean that the electricity scenario in La Rioja will undergo spectacular change over the coming years: we examine the possibility of meeting a target of practical electrical self-sufficiency by 2010.In 2004, power consumption amounted to 1494 GWh, with an installed power of 1029.0 MW of electricity. By 2010, the Arrúbal combined cycle facility will produce around 9600 GWh/year, thereby providing a power generation output in La Rioja of close to 2044.7 MW, which will involve almost doubling the present output, and multiplying by 8.9 that recorded in this Autonomous Community in 2001.     

Wind energy status in renewable electrical energy production in Turkey

Main electrical energy sources of Turkey are thermal and hydraulic. Most of the thermal sources are derived from natural gas. Turkey imports natural gas; therefore, decreasing usage of natural gas is very important for both economical and environmental aspects. Because of disadvantages of fossil fuels, renewable energy sources are getting importance for sustainable energy development and environmental protection. Among the renewable sources, Turkey has very high wind energy potential. The estimated wind power capacity of Turkey is about 83,000 MW while only 10,000 MW of it seems to be economically feasible to use. Start 2009, the total installed wind power capacity of Turkey was only 4.3% of its total economical wind power potential (433 MW). However, the strong development of wind energy in Turkey is expected to continue in the coming years. In this study, Turkey's installed electric power capacity, electric energy production is investigated and also Turkey current wind energy status is examined.     

Future of renewable energies in Iran

The activities in field of renewable energy in Iran are focused on scientific and research aspects, and research part is aimed at reduction of capital required for exploitation of related resources. The second step is to work research results into scientific dimension of this field for practical means, i.e. establishing electricity power plants. Due to recent advancements in wind energy, many investors in the country have become interested in investing in this type of energy. At the moment, projects assuming 130 MW of wind power plants are underway, of which, 25 MW is operational. Based on the planning in the 4th Socioeconomic and Cultural Development Plan (2005–2010), private sector is expected to have a share of at least 270 MW in renewable energies. However, it is the government's duty to take the first step for investment in biomass and solar power plants; private sector may then play its part once the infrastructures to this end are laid out. At the moment, a 250 kW plant is under construction in Shiraz and two more geothermal units with 5 and 50 MW capacities will follow. Moreover, two biomass and solar energy plants, standing at 10 and 17 MW, respectively, are of other upcoming projects. The project of Iran's renewable energy, aims to accelerate the sustainable development of wind energy through investment and removal of barriers. This preparatory project is funded by the global environment facility (GEF) and will provide for a number of international and national consultant missions and studies. Once the studies are concluded, a project to develop 25 MW of wind energy in the Manjil region of Gilan will be prepared. It will be consistent with the national development frameworks and objectives and form part of 100 MW of wind-powered energy, which is expected to be developed under the government's third 5-year national development plan (started 21 March 2000).     

The use of green waste from tourist attractions for renewable energy production: The potential and policy implications

Quantifying potential renewable energy sources from tourist attractions is a pivotal initial step in developing energy policies and strategies for low-carbon tourist industry development. Although solar energy and wind power have been in use for providing power for tourist attractions, the value of using waste biomass for energy production is still poorly understood. Here we advocate a promising approach that produces energy from green waste created by tourism attractions currently existing in large numbers and is still increasing dramatically. Using the Yangtze River Delta (YRD) of China as an example, we evaluated the potential of utilizing green waste to produce energy from 385 tourist attractions in 16 cities of this region. Our results showed that the total potential energy production using the green waste biomass was estimated at 6740 TJ/yr (1 TJ=10¹² J) with an average of 137 GJ/ha/yr (1 GJ=10⁹ J), accounting for 6% (the average of the Yangtze River Delta, some scenic areas up to 93%) of YRD′s tourism industry′s energy consumption in 2008. The use of green waste for energy production is possible using current technology and could result in a win–win approach by reducing waste and increasing the renewable energy yields.     

Short–mid-term solar power prediction by using artificial neural networks

Solar irradiation is one of the major renewable energy sources and technologies related with this source have reached to high level applications. Prediction of solar irradiation shows some uncertainties depending on atmospheric parameters such as temperature, cloud amount, dust and relative humidity. These conditions add new uncertainties to the prediction of this astronomical parameter. In this case, prediction of generated electricity by photovoltaic or other solar technologies could be better than directly solar irradiation.In this paper, firstly, Artificial Neural Networks (ANNs) methodology is applied to data obtained from a 750 W power capacity of solar PV panel. The main objective of this paper is to determine time horizon having the highest representative for generated electricity prediction of small scale solar power system applications. It is seen that 5 min time horizon gives the best solar power prediction for short term and 35 min could be used for medium terms in April. In addition, these time horizons have increased to 3 and 40 min for very short time and medium time prediction respectively during August. During April and August Root Mean Square Errors (RMSEs) between measured and testing values changed between 33–55 W and 37–63 W ranges respectively. Especially, during August for solar irradiation, stationary conditions are observed and these situations let ANN predict easily generated electricity from 30 to 300 min ahead.     

Experimental studying of a small combined cold and power system driven by a micro gas turbine

A small combined cold and power (SCCP) system is presented. An experimental study of the performance of the SCCP system is described. The gas fuelled SCCP system uses a micro gas turbine generator set and an absorption chiller. The test facility designed and built is also described. The rated electricity power of the micro gas turbine generator is about 24.5 kW at the experimental conditions. When exhaust gas from the micro gas turbine is used to drive the absorption chiller, the rated cooling capacity is 52.7 kW without supplying fuel to burn in the absorption chiller and 136.2 kW with supplying about 78.9 kW LPG fuel to burn in the absorption chiller, respectively. Primary energy rate (PER) and comparative saving of primary energy demand are used to evaluate the performance of the SCCP system. PER of the SCCP system decreases rapidly with the decrease of electric power output when the electric power output is less than 10 kW. The calculated results also show that comparative saving of primary energy demand of the SCCP system decreases with the decrease of electric power output and the SCCP system do not save primary energy comparing to conventional energy system when the electric power output is less than 10 kW.     

Assessment of the renewable energies potential for intensive electricity production in the province of Jaén,southern Spain

The foreseen depletion of the traditional fossil fuels for the forthcoming decades is forcing us to seek for new sustainable and non-pollutant energy sources. Renewable energies rely on a decentralized scheme strongly dependent on the local resources availability. In this work, we tackle the study of the renewable energies potential for an intensive electricity production in the province of Jaén (southern Spain) which has a pronounced unbalance between its inner electricity production and consumption. The potential of biomass from olive pruning residues, solar photovoltaics (PV) and wind power has been analyzed using Geographical Information System tools, and a proposal for a massive implementation of renewable energies has been arisen. In particular, we propose the installation of 5 biomass facilities, totaling 98 MW of power capacity, with an estimated annual production of 763 GWh, 12 PV facilities, totaling 420 MW of power capacity, with an estimated annual production of 656 GWh and 506 MW of wind power capacity in a number of wind farms, with an estimated annual production of 825 GWh. Overall, this production frame would meet roughly a 75% of the electricity demands in the province and thus would mitigate the current unbalance.     

Biomass and central receiver system (CRS) hybridization: Volumetric air CRS and integration of a biomass waste direct burning boiler on steam cycle

Concentrated solar power (CSP) plants generate an almost continuous flow of fully dispatchable “renewable” electricity and can replace the present fossil fuel power plants for base load electricity generation. Nevertheless, actual CSP plants have moderate electricity costs, in most cases quite low capacity factors and transient problems due to high inertia. Hybridization can help solve these problems and, if done with the integration of forest waste biomass, the “renewable” goal can be maintained, with positive impact on forest fire reduction. Local conditions, resources and feed in tariffs have great impact on the economical and technical evaluation of hybrid solutions; one of the premium European locations for this type of power plants is the Portuguese Algarve region.Due to the concept innovation level, conservative approaches were considered to be the best solutions. In this perspective, for a lower capital investment 4 MWe power plant scale, the best technical/economical solution is the hybrid CRS/biomass power plant HVIB3S4s with CS3 control strategy. It results in a levelized electricity cost (LEC) of 0.146 €/kWh, with higher efficiency and capacity factor than a conventional 4 MWe CRS. A larger 10 MWe hybrid power plant HVIB3S10s could generate electricity with positive economical indicators (LEC of 0.108 €/kWh and IRR of 11.0%), with twice the annual efficiency (feedstock to electricity) and lower costs than a conventional 4 MWe CRS. It would also lead to a 17% reduction in biomass consumption (approximately 12,000 tons less per year) when compared with a typical 10 MWe biomass power plant – FRB10; this would be significant in the case of continuous biomass price increase.     

An algorithm for selection and design of hybrid power supplies for MEMS with a case study of a micro-gas chromatograph system

The Wireless Integrated Microsystems (WIMS)-environmental monitor testbed (EMT) is a multi-component microelectromechanical system (MEMS), incorporating complementary metal oxide semiconductor (CMOS) materials for high-precision circuits used for integrated sensors such as micro-g accelerometers, micro-gyroscopes, and pressure sensors. The WIMS–EMT duty cycle, like many autonomous MEMS systems, has low-power standby periods for sensing, and high-power pulses for R/F transmission and reception. In this paper, we present results of three strategies for providing power to this system, including (1) specification of a single, aggregate power supply, resulting in a single battery electrochemistry and cell size; (2) specification of several power supplies, by a priori division of power sources by power range; and (3) specification of an arbitrary number of power “bundles,” based on available space in the device. The second approach provided the best results of mass (0.032 kg) and volume (0.028 L) among the three approaches. The second and third approaches provided the best battery lifetime results; both systems produced lifetimes in excess of 2E3 h. Future work will incorporate CMOS operational amplifier (op-amp) technologies to accommodate large voltage fluxes in many MEMS devices, and implementation of our approaches into a user-friendly code.     

Energy consumption reduction of a PEM fuel cell motor-compressor group thanks to efficient control laws

This paper deals with the energy optimization of an embedded fuel cell generator. To reach this aim, experimentally validated models of a low power 5 kW proton exchange membrane fuel cell (PEMFC) and its most power hungry ancillary (motor-compressor group) are described. All simulation results have been performed using Matlab/Simulink^® environment. Moreover, a control strategy of the air supply circuit integrated in an embedded fuel cell system is proposed. The air flow control of the air supply circuit is built around a fuzzy PD + I controller and for the air supply set point determination, a fuzzy supervision is proposed. The parameters of this fuzzy supervision have been optimized thanks to particle swarm optimization (PSO) method.     

As a renewable energy hydropower for sustainable development in Turkey

The most important renewable sources are hydropower, biomass, geothermal, solar and wind. Turkey's geographical location has several advantages for extensive use of most of these renewable energy sources. In recently, electricity has demand increased significantly; it is the fastest growing end-use of energy. Therefore, technical, economic and environmental benefits of hydroelectric power make it an important contributor to the future world energy mix. In the world, particularly in the developing countries renewable energy resources appear to be one of the most efficient and effective solutions for sustainable energy development in Turkey. Turkey's geographical location has several advantages for extensive use of most of the renewable energy sources. This paper deals with policies to meet increasing energy and electricity demand for sustainable energy development in Turkey. Turkey has a total gross hydropower potential of 433 GWh/year, but only 125 GWh/year of the total hydroelectric potential of Turkey can be economically used.