Promotional policy for renewable energy development in Taiwan

On June 12, 2009, Taiwan government approved a bill of “Statute for Renewable Energy Development”, which aimed at promoting the use of renewable energy, boosting energy diversification, and helping reduce greenhouse gases. The new act caps the subsidies for renewable energy up to 10 GW within 20 years. It authorizes the government to enhance incentives for the development of renewable energy via a variety of methods, including the acquisition mechanisms, incentives for demonstration projects, and the loosening of regulatory restrictions. According to the subsidies of the Statute, the share of power capacity of renewable energies will be triple of the nationwide power installation capacity by 2029. The purpose of this paper is to present an updated overview of promotional policy of renewable energy in Taiwan, in addition to evaluate the growth space of individual renewable energies in the post-Statute era by considering the technology development, domestic conditions, and indigenous industries related to renewable energy.     

Insights for global energy interconnection from China renewable energy development

Vigorously developing global renewable energy such as wind energy, solar energy, and hydropower and realizing global clean resource sharing are paramount driving forces for building the Global Energy Interconnection (GEI). With the help of a comparative analysis of renewable energy development and global renewable energy development scenarios, this paper expounds on the similarities between China1 and global renewable energy development. Based on the analysis of renewable energy development and the status of global renewable energy development in China, this paper summarizes the relevant experience and problems of renewable energy development in China. According to these problems, this paper also puts forward the corresponding solutions and measures, that is, to promote the healthy and steady development of renewable energy in China through the source-network-load-storage and market coordination. Finally, by analyzing the development requirements and current foundation of GEI, insights and suggestions are proposed for the future development of renewable energy for the GEI construction.     

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.     

Full-scale co-firing trial tests of sawdust and bio-waste in pulverized coal-fired 230 t/h steam boiler

Co-firing trial tests of sawdust and bio-waste coming from cereal production with hard coal were carried out at Skawina Power Plant in Poland (1532 MW in fuel, currently belonging to CEZ Group). Skawina Power Plant is a tangentially-fired pulverized coal unit with nine boilers (4 boilers of 210 t/h and five boilers of 230 t/h live steam respectively) that produces 590 MW electricity and 618 MW of heat (district heating and process steam).The paper presents an analysis of energy and ecological effects of sawdust and bio-waste co-firing in the existing pulverized hard coal boiler. The mixture of coal and biomass was blended in the coal yard, and fed into the boiler through the coal mills. During the tests, combustion of mixtures composed of hard coal and sawdust (with mass share of 9.5%) and hard coal – bio-waste (6.6% mass basis) were examined. The co-firing tests were successful. Based on the analysis of the test results, the influence of biomass co-firing on specific components of energy balance (e.g. stack losses and boiler thermal efficiency) was discussed, in comparison to combustion of coal alone. The emission indices during coal combustion were calculated and compared to the emission indices for biomass co-firing. It was proved that co-firing of both biomass sorts leads to a decrease of CO and SO₂ emissions. Due to the possibility of considering the part of the energy generated during biomass co-firing as renewable energy, the procedure for biomass based renewable energy share determination is presented and illustrated with an example.     

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.     

Wave climate off the Swedish west coast

This paper presents and discusses the wave climate off the Swedish west coast. It is based on 8 years (1997–2004) of wave data from 13 sites, nearshore and offshore, in the Skagerrak and Kattegat. The data is a product of the WAM and SWAN wave models calibrated at one site by a wave measurement buoy. It is found that the average energy flux is approximately 5.2 kW/m in the offshore Skagerrak, 2.8 kW/m in the nearshore Skagerrak, and 2.4 kW/m in the Kattegat. One of the studied sites, i.e. site 9, is the location of a wave energy research site run by the Centre for Renewable Electric Energy Conversion at Uppsala University. This site has had a wave power plant installed since the spring of 2006, and another seven are planned to be installed during 2008. Wave energy as a renewable energy source was the driving interest that led to this study and the results are briefly discussed from this perspective.     

Integration and development of energy and information network in the Pan-Arctic region

The Global Energy Interconnection is an important strategic approach used to achieve efficient worldwide energy allocation. The idea of developing integrated power, information, and transportation networks provides increased power interconnection functionality and meaning, helps condense forces, and accelerates the integration of global infrastructure. Correspondingly, it is envisaged that it will become the trend of industrial technological development in the future. In consideration of the current trend of integrated development, this study evaluates a possible plan of coordinated development of fiber-optic and power networks in the Pan-Arctic region. Firstly, the backbone network architecture of Global Energy Interconnection is introduced and the importance of the Arctic energy backbone network is confirmed. The energy consumption and developmental trend of global data centers are then analyzed. Subsequently, the global network traffic is predicted and analyzed by means of a polynomial regression model. Finally, in combination with the current construction of fiber-optic networks in the Pan-Arctic region, the advantages of the integration of the fiber-optic and power networks in this region are clarified in justification of the decision for the development of a Global Energy Interconnection scheme.     

Viability analysis of PV power plants in Egypt

This paper investigates, from techno-economical and environmental points of view, the feasible sites in Egypt to build a 10 MW PV-grid connected power plant. Available PV-modules are assessed and a module is selected for this study. The long-term meteorological parameters for each of the 29 considered sites in Egypt from NASA renewable energy resource website (Surface meteorology and Solar Energy) are collected and analyzed in order to study the behaviors of solar radiations, sunshine duration, air temperature, and humidity over Egypt, and also to determine the compatibility of the meteorological parameters in Egypt with the safety operating conditions (SOC) of PV-modules. The project viability analysis is performed using RETScreen version 4.0 software through electric energy production analysis, financial analysis, and GHG emission analysis. The study show that placement of the proposed 10 MW PV-grid connected power plant at Wahat Kharga site offers the highest profitability, energy production, and GHG emission reduction. The lowest profitability and energy production values are offered at Safaga site. Therefore, it is recommended to start building large-scale PV power plants projects at Wahat Kharga site.     

Further evidence of impacts of large-scale wind farms on land surface temperature

Large wind farms are power plants that generate clean energy from a renewable source. They are increasingly being installed and operated to replace and complement fossil fuel power plants in an effort to help reduce greenhouse and other pollutant emissions (American Wind Energy Association, 2012 [1]; American Wind Energy Association, 2011 [2]; Global Wind Energy Council, 2011 [3]; US Department of Energy, 2008 [4]; Wiser et al., 2007 [5]). Wind energy can have a positive economic impact and numerous locations on the planet are good candidates for wind energy production. Any direct environmental impact of large-scale wind farms needs to be investigated because it could impact agriculture, economics, health, society, and technology. A recent study showed that surface temperature is observed to increase directly downwind of large wind farms [6]. This research, performed concurrently, shows that similar and complementary results are obtained for a different location, and using remotely sensed temperature data obtained from a different satellite, at higher resolution and for a longer time span. Satellite remote sensing observations from Landsat 5 Thematic Mapper are used to study temperature changes over the San Gorgonio Pass Wind Farm from 1984 to 2011, with a pixel resolution of 120 m. A warming trend is consistently observed downwind of the wind farm.     

Fuel cell operation on landfill gas at Penrose Power Station

This demonstration test successfully demonstrated the operation of a commercial phosphoric acid fuel cell (FC) on landfill gas (LG) at the Penrose Power Station in Sun Valley, CA. Demonstration output included operation up to 137 kW; 37.1% efficiency at 120 kW; exceptionally low secondary emissions (dry gas, 15% O₂) of 0.77 ppmV CO, 0.12 ppmV NO_x, and undetectable SO₂; no forced outages with an adjusted availability of 98.5%; and a total of 707 h of operation on LG. The LG pretreatment unit (GPU) operated for a total of 2297 h, including the 707 h with the FC, and documented total sulfur and halide removal to much lower than the specified <3 ppmV for the FC. The GPU flare safely disposed of the removed LG contaminants by achieving destruction efficiencies greater than 99%.     

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.     

The Hokuto mega-solar project

Solar generation systems are one of the measures for reducing global warming. An installed capacity target of solar generation systems in our country will be set 4.82 GW in 2010, while the total installed capacity is still 1.92 GW in 2007. About 80% of the systems are mainly residential use and each is very small. Constructions of some large-scale solar generation systems will be expected and intensive development of related technologies are urgent. The New Energy and Industrial Technology Development Organization (NEDO) advertised for consignment research business “Verification of Grid Stabilization with Large-scale Photovoltaic (PV) Power Generation Systems” in 2006. The verification tests are carried out in two sites of Hokuto City, Yamanashi Prefecture and Wakkanai City, Hokkaido. The outlines and the developing targets and some of studying results of the Hokuto mega-solar project (HMSP) are introduced in this paper.     

Spatial mapping of renewable energy potential

An energy resource that is renewed by nature and whose supply is not affected by the rate of consumption is often termed as renewable energy. The need to search for renewable, alternate and non-polluting sources of energy assumes top priority for self-reliance in the regional energy supply. This demands an estimation of available energy resources spatially to evolve better management strategies for ensuring sustainability of resources. The spatial mapping of availability and demand of energy resources would help in the integrated regional energy planning through an appropriate energy supply–demand matching. This paper discusses the application of Geographical Information System (GIS) to map the renewable energy potential talukwise in Karnataka State, India. Taluk is an administrative division in the federal set-up in India to implement developmental programmes like dissemination of biogas, improved stoves, etc. Hence, this paper focuses talukwise mapping of renewable energy (solar, wind, bioenergy and small hydroenergy) potential for Karnataka using GIS. GIS helps in spatial and temporal analyses of the resources and demand and also aids as Decision Support System while implementing location-specific renewable energy technologies.Regions suitable for tapping solar energy are mapped based on global solar radiation data, which provides a picture of the potential. Coastal taluks in Uttara Kannada have higher global solar radiation during summer (6.31 kWh/m²), monsoon (4.16 kWh/m²) and winter (5.48 kWh/m²). Mapping of regions suitable for tapping wind energy has been done based on wind velocity data, and it shows that Chikkodi taluk, Belgaum district, has higher potential during summer (6.06 m/s), monsoon (8.27 m/s) and winter (5.19 m/s). Mysore district has the maximum number of small hydropower plants with a capacity of 36 MW. Talukwise computation of bioenergy availability from agricultural residue, forest, horticulture, plantation and livestock indicates that Channagiri taluk in Shimoga district yields maximum bioenergy. The bioenergy status analysis shows that Siddapur taluk in Uttara Kannada district has the highest bioenergy status of 2.004 (ratio of bioresource availability and demand).     

Feasibility of pico-hydro and photovoltaic hybrid power systems for remote villages in Cameroon

Pico-hydro (pH) and photovoltaic (PV) hybrid systems incorporating a biogas generator have been simulated for remote villages in Cameroon using a load of 73 kWh/day and 8.3 kWp. Renewable energy systems were simulated using HOMER, the load profile of a hostel in Cameroon, the solar insolation of Garoua and the flow of river Mungo. For a 40% increase in the cost of imported power system components, the cost of energy was found to be either 0.352 €/kWh for a 5 kW pico-hydro generator with 72 kWh storage or 0.396 €/kWh for a 3 kWp photovoltaic generator with 36 kWh storage. These energy costs were obtained with a biomass resource cost of 25 €/tonne. The pH and PV hybrid systems both required the parallel operation of a 3.3 kW battery inverter with a 10 kW biogas generator. The pH/biogas/battery systems simulated for villages located in the south of Cameroon with a flow rate of at least 92 l/s produced lower energy costs than PV/biogas/battery systems simulated for villages in the north of Cameroon with an insolation level of at least 5.55 kWh/m²/day. For a single-wire grid extension cost of 5000 €/km, operation and maintenance costs of 125 €/yr/km and a grid power price of 0.1 €/kWh, the breakeven grid extension distances were found to be 12.9 km for pH/biogas/battery systems and 15.2 km for PV/biogas/battery systems respectively. Investments in biogas based renewable energy systems could thus be considered in the National Energy Action Plan of Cameroon for the supply of energy to key sectors involved in poverty alleviation.     

Management alternatives of energy wood thinning stands

Energy wood thinning has become a feasible treatment alternative of young stands in Finland. Energy wood thinnings have been carried out mainly in stands where precommercial thinning has been neglected and the harvesting conditions for industrial wood thinning are difficult. Despite of its positive effects on harvesting costs and on renewable energy potential, whole-tree harvesting has been constantly criticized for causing growth loss. In this paper, the profitability of energy wood thinning was studied in 20 Scots pine-dominated stands where energy wood thinning was carried out. The growth of the stands after thinning was predicted with the help of Motti-stand simulator. Entire rotation time of the stands was simulated with different management alternatives. The intensity of first thinning and recovery level of logging residues varied between alternatives. In order to attain acceptable harvesting conditions, industrial wood thinning had to be delayed. The effect of energy wood thinning on subsequent stem wood growth was almost the same as in conventional thinning. Whole-tree harvesting for energy proved to be profitable alternative if the stumpage price is around 3€ m⁻³, the interest rate is 3% or 5% and the removal of pulpwood is less than 20 m³ ha⁻¹. If the harvestable pulpwood yield is over 20 m³ ha⁻¹, integrated harvesting of industrial and energy wood or delayed industrial wood harvesting becomes more profitable.     

海底电缆超短基线定位系统误差分析及处理策略

  [目的]  超短基线定位是一种重要的水下声学定位方式,主要解决超短基线定位远距离定位发散快,远距离定位精度不高的缺点。  [方法]  论文介绍了超短基线定位系统的原理,详细分析了引起超短基线定位误差的各种因素,并针对这些因素,提出了相应的处理策略,从而提高水下定位精度,  [结果]  结合海南联网海底电缆检测实际应用,验证将超短基线定位处理策略在克服距离定位发散快,远距离定位精度不高的缺陷的有效性。  [结论]  海南联网海底电缆检测实际应用实践验证了针对超短基线远距离定位发散快、定位精度不高的处理策略在海底高精度定位的有效性。     

Hydropower for sustainable energy development in Turkey: The small hydropower case of the Eastern Black Sea Region

Turkey is a rich country from the point of variety and potential of renewable energy resources. Hydros, winds, biomass, solar and geothermal are important renewable and environmentally friendly sources for energy in Turkey. Turkey produces large amount of hydropower with a total gross hydropower potential of 433 TW h/yr, which is equal to 13.8% of the total hydropower potential of Europe. Technically useable potential is 216 TW h/yr and economic potential is 140 TW h/yr. The main aim of the present study is to investigate hydropower potential of Turkey and small hydropower plants in Eastern Black Sea Region for sustainable energy development in Turkey. The geography of Turkey especially, Eastern Black Sea Region supports and suitable the development of the small hydro plants to increase the energy generation and utilization of available water sources in Turkey. Besides, the paper deals with hydropower policies to meet ever increasing energy demand for sustainable development of Turkey.     

Current status of ground source heat pumps in Korea

In Korea, ground source heat pumps (GSHP) have been gaining popularity for space heating and cooling. Because there are few sources of high-temperature geothermal energy in the country, public baths (25–40 °C) and geothermal heat pumps (～15 °C) using low-temperature groundwater or ground are the most dominant direct geothermal uses. The Promotion Law of the New and Renewable Energy Development, Use and Dissemination, enacted in 2004, imposed an obligatory installation of space heating and cooling systems using new and renewable energy sources including geothermal energy for newly constructed public buildings (more than 5% of total construction cost). Between 2004 and 2007, ground source heat pump systems occupied about 60% of the total public installation of new and renewable energy equipment. Starting with 35.2 kW of two facilities in 2000, systems with the capacity of over 127.1 MWt have been installed in 551 buildings (facilities) as of August 2008. The vertical closed heat pump system (closed loop) and the groundwater heat pump system (standing column well type; SCW) occupied 65.1% and 29.3%, respectively, among the total GSHP systems installed. The depth of the vertical loops ranged between 65 and 250 m (average 159 m) and the well depth of the SCW system ranged between 150 and 600 m (average 391 m). The number of geothermal energy companies, installing the GSHP systems, that are officially registered in the relevant authority increased from 5 in 2000 to 397 in July 2008. This paper presents details of the current status of ground source heat pumps in Korea.     

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.     

Hydrogen production through an ocean thermal energy conversion system operating at an optimum temperature drop

Storage of electrical energy produced from an ocean thermal energy conversion (OTEC) system is considered to be extremely essential, since the conversion process could take place in a remote offshore area and distant from the actual utilization sites. Energy conversion from an OTEC system into hydrogen energy, which is used for power generation through fuel cells, is an important approach of storing such energy for further utilizations. In this paper, a technical analysis of hydrogen production through an OTEC system coupled with a polymer electrolyte membrane electrolyser (PEM), which is developed by the Japanese international clean energy network using hydrogen conversion (WE-NET), is performed. The analysis is conducted at an optimum temperature drop between the working fluid and seawater, δT_op. Furthermore, the analysis is carried out at various temperature differences between the surface and deep sea water, ΔT. The calculated results demonstrated the significance of temperature drop and temperature difference on the electrical power output and conversion efficiency. Moreover, the actual rate of hydrogen production varied from 2.5 N m³/h to 60 N m³/h as ΔT raised from 5 °C to 25 °C, respectively.