Implementation of MIR SOLAR heliosystems in Uzbekistan

Information about photoelectric stations and heliosystems of hot water supply operated at different facilities of Uzbekistan is presented. In recent years in all countries of the world, much attention has been focused on the issues of using renewable energy sources. Solar radiation energy is most prospective among the renewable energy sources under the climate conditions of our republic based on its scales of resources and availability over the whole territory.     

炼油装置余热回收集中热水供应技术研究

为回收炼油装置丰富的低温余热用于生活区的集中供热,对余热资源和生活热水供应热负荷分别进行了综合标定和统计计算,在分析比较的基础上确定采用热管换热器回收余热和双管制生活热水集中供应系统方案,并对余热流股热回收的热管换热器进行了设计计算。集中热水供应系统的技术经济分析表明,该方案在技术上是可行的,节能效果和经济效益十分显著。     

Technical–economical analysis of the Saveh biogas power plant

The resource limitation of fossil fuels and the problems arising from their combustion has led to widespread research on the accessibility of new and renewable energy resources. Solar, wind, thermal and hydro sources, and finally biogas are among these renewable energy resources. But what makes biogas distinct from other renewable energies is its importance in controlling and collecting organic waste material and at the same time producing fertilizer and water for use in agricultural irrigation. Unlike other forms of renewable energy, biogas neither has any geographical limitations and required technology for producing energy and nor is it complex or monopolistic. Considering the ever increasing amount of different types of organic waste materials (about 15 million tonnes) in Iran, working on the control of waste material and biogas production becomes inevitable.In this paper, biogas and the benefits from its production are discussed, as is the technical-economic analysis of the Saveh biogas power plant as a case study.     

International policy issues regarding solar water heating, with a focus on New Zealand

Like many countries New Zealand is moving towards renewable energy targets and has recently (November 2006) announced a revised solar hot water heating subsidy program that is being implemented through the Energy Efficiency and Conservation Authority (EECA). This paper describes the new program and reviews international policies regarding solar water heating to see which aspects have been effective in gaining an increased penetration of solar systems for water heating. In addition, the factors leading to successful policy implementation and the possible downsides of the 2006 New Zealand policy are discussed with regard to international experience.     

Thermal processing of waste organic substrates: Developing and applying an integrated framework for feasibility assessment in developing countries

Against the background of global climate change and increasing prices of fossil fuel, the importance of producing sustainable renewable energy increases significantly. CO₂-neutral energy generation using biomass or organic waste is an alternative option that deserves attention particularly in developing countries. Aim of this paper is to provide an integrated framework for the preparation of feasibility studies for the renewable energy sector there, considering technical, environmental, economic, socio-cultural, legal and institutional aspects which are particular applicable for developing countries. Such a feasibility framework involves a definition of the scope, which reflects the aims and objectives of the target groups (supplier, operator, etc. of renewable energy supply) and the methodologies and tools involved. All relevant aspects are covered: data collection, selection of sites and assessment of options. Furthermore, methods and tools for risk assessment and decision-making are presented and a practical plan of procedures is last provided. The proposed framework is then applied to a selected area in Vietnam and certain results of the study, showing that the implementation of a biogas plant utilizing organic waste would be feasible, are presented in this paper.     

Wind energy in Sudan : Water pumping in rural areas

New and renewable sources of energy can make an increasing contribution to the energy supply mix of developing countries in view of favourable renewable energy resource endowments, limitations and uncertainties of fossil fuel supplies, adverse balance of payments, and the increasing pressure on the environment from conventional energy generation. Among the renewable energy technologies, the generation of mechanical and electric power by wind machines has emerged as an economically viable and cost effective option. Therefore the Sudanese government has begun to pay more attention to the use of wind energy in rural areas in particular as a cost-effective solution to assist in water pumping and irrigation.     

Simulating reservoir storage for a wind-hydro hydrid system

A wind-hydro hybrid system is proposed to improve Brazil's use of its renewable energy portfolio. In this scheme, winds from local or remote locations supply extra generation, so that the hydroelectric outflow can be reduced accordingly to wind production. The water savings, in turn, lead to a significant improvement of the reservoir's storage. A simple model is developed and applied to the Itumbiara hydroelectric reservoir of midwest Brazil. Scenarios for different wind contributions are compared to historical observations from 1994 to 2011. Results suggest that, if implemented, the hybrid system should improve the country's energy security. Hydroelectric reservoirs might be able to confront interannual climate variability without risks to the energy supply. A positive impact on the multiple use of reservoirs is expected for fish-farming, irrigation, recreation, navigation and water supply.     

Stand-alone micro-trigeneration system coupling electrolyzer,fuel cell,and heat pump with renewables

A micro hydrogen system in conjunction with renewable energy, namely a wind turbine, a photovoltaic array, and an air-source heat pump, is designed to satisfy the power, heating, and cooling needs of a stand-alone household in a Mediterranean climate. An hourly-based model is used to simulate its operation throughout the year. A unique power management strategy is applied to achieve optimum configuration and size of the components without shortage or excess energy. Unlike previous practices, there is no release of excess heat into the environment. An innovative combination of a fuel cell and a heat pump followed the household's electrical and thermal (domestic hot water/heating and space cooling) profile. Almost 80% of the energy for preparing hot water and household cooling/heating was obtained from waste heat from these devices. The system is compared to the most commonly used stand-alone hybrid renewable energy system with battery storage. The hydrogen system needs four time less batteries and it does not need a back-up diesel generator. Although the energy storage in batteries is more efficient than in hydrogen, the hydrogen system requires only 10% larger primary energy input than the system with only battery storage.     

Thermal desalination of ballast water using onboard waste heat in marine industry

Ballast water management is a national and international issue in the shipping industry because of potential ecological hazards caused by the release of ballast water into the marine environment. Although many international standards have been implemented in recent years, technological and practical considerations make the ballast water treatment a major challenge for many shipping companies. In this paper, a novel concept of utilizing ballast water as source water for a multieffect desalination process driven by onboard waste heat to meet the freshwater supply needs is proposed with theoretical analysis and practical considerations. A main engine with a capacity of 7500 kW in a cruise ship can serve as a potential waste heat source for water desalination of 1000 m³/d, which can provide for freshwater needs of 2000 to 4000 ship occupants. This scenario presents an attractive alternative to ballast water management and treatment as well as reducing the nonrenewable energy footprint of onboard water supplies in marine industry.     

Review of wind energy use in Algeria

Most scientists now agree that human-induced global climate change poses a serious threat to both society and the Earth's ecosystems. Renewable energy holds the key to future prosperity and a healthy global environment and is considered as a promising way to solve the problem of environmental pollution such as major environmental accidents, water pollution, maritime pollution, land use and sitting impact, radiation and radioactivity, solid waste disposal, hazardous air pollutants, ambient air quality (CO, CO₂, SO_x, NO_x effluent gas emissions), acid rain, stratospheric ozone depletion, and global warming (GHG). Solar, wind and hydrogen power can be considered as potential renewable energy sources in Algeria. The share of renewable energy sources in Algeria primary energy supply is relatively low compared with European countries, though the trends of development are positive. One of the main strategic priorities of New Energy Algeria (NEAL) which is Algeria's renewable energy agency (government, Sonelgaz and Sonatrach), is striving to achieve a share of renewable energy sources in primary energy supply of 10–12% by 2010. IEA projects that the fastest growing sources of energy will be supplied by renewables. Much of this capacity will be installed in developing nations where solar and wind electric power is already competitive. Clearly, the nation that can capture a leadership position has potential for substantial economic returns. The article presents a review of the present wind energy situation and assessed potential of wind energy sources in Algeria in particular the southwest region of Algeria (Adrar, Timimoun and Tindouf).     

利用窑系统废气余热提供生活热水

介绍水泥厂利用窑系统冷却机废气余热解决了生产工人洗热水的供应问题,分析了项目实施后的节能效益。     

Technoeconomic optimization of solar natural convection hybrid hot water systems

In this paper a techno-economic model for a hybrid domestic hot water system operating under natural convection mode is presented. Three modes of auxiliary energy supply viz.

• A electric heater fitted in the solar hot water tank.
• B electric heater fitted in a small water tank in series with the solar hot water tank, and
• C an instant electric heater fitted in the tap

have been considered. Taking into account the life and the capital and maintenance costs of the solar and electrical equipments, the cost of useful energy (Rs/kWh) has been calculated for different values of the collector area and the tank capacity, and thereby the optimum collector area and tank capacity (for a given demand), corresponding to minimum cost of useful energy, has been determined. From numerical calculations made for the climate of Delhi, India (a representative composite climate) corresponding to the two cases of monthly hot water demand viz. (i) constant monthly demand, and (ii) variable monthly demand, it is seen that case (C) is the most economic design of the hybrid hot water system; numerical calculations have also been made for this case corresponding to the climates of Srinagar and Madras (representing cold and hot climates). The effect of government subsidy on the optimized values of collector area, tank capacity and cost of useful energy has also been investigated for the climate of Delhi.     

Energy [R]evolution 2010??a sustainable world energy outlook

The Energy [R]evolution 2010 scenario is an update of the Energy [R]evolution scenarios published in 2007 and 2008. It takes up recent trends in global energy demand and production and analyses to which extent this affects chances for achieving climate protection targets. The main target is to reduce global CO₂ emissions to 3.7 Gt/a in 2050, thus limiting global average temperature increase to below 2°C and preventing dangerous anthropogenic interference with the climate system. A ten-region energy system model is used for simulating global energy supply strategies. A review of sector and region specific energy efficiency measures resulted in the specification of a global energy demand scenario incorporating strong energy efficiency measures. The corresponding supply scenario has been developed in an iterative process in close cooperation with stakeholders and regional counterparts from academia, NGOs and the renewable energy industry. The Energy [R]evolution scenario shows that renewable energy can provide more than 80% of the world’s energy needs by 2050. Developing countries can virtually stabilise their CO₂ emissions by 2025 and reduce afterwards, whilst at the same time increasing energy consumption due to economic growth. OECD countries will be able to reduce their emissions by up to 90% by 2050. However, without a comprehensive energy efficiency implementation strategy across all sectors, the renewable energy development alone will not be enough to make these drastic emissions cuts.     

An energy management approach for renewable energy integration with power generation and water desalination

The share of the renewable energy sources (RES) in the global electricity market is substantially increasing as a result of the commitment of many countries to increase the contribution of the RES to their energy mix. However, the integration of RES in the electricity grid increases the complexity of the grid management due to the variability and the intermittent nature of these energy sources. Energy storage solutions such as batteries offer either short-term storage that is not sufficient or longer period storage that is significantly expensive. This paper introduces an energy management approach which can be applied in the case of power and desalinated water generation. The approach is based on mathematical optimization model which accounts for random variations in demands and energy supply. The approach allows using desalination plants as a deferrable load to mitigate for the variability of the renewable energy supply and water and/or electricity demands. A mathematical linear programming model is developed to show the applicability of this idea and its effectiveness in reducing the impact of the uncertainty in the environment. The model is solved for the real world case of Saudi Arabia. The optimal solution accounts for random variations in the renewable energy supply and water and/or electricity demands while minimizing the total costs for generating water and power.     

Renewable energy applications in desalination: state of the art

Millions of people have no access to a secure source of fresh water. Nevertheless, since many arid regions are coastal areas, seawater desalination is a reasonable alternative. On the other hand, the energy requirements of desalination processes are high. Then, the energy supply in low development countries or isolated areas may be a problem, especially if electricity is required. Since most arid regions have high renewable energy resources, the use of renewable energies in seawater desalination exhibits an interesting chance, or even the only way to offer a secure source of fresh water. The status and perspectives of development of coupling renewable energy systems with desalination units are reviewed. It is pointed out that there are place of development even for such technologies that seem to be the most mature ones.     

Renewable energy technologies for irrigation water pumping in India: projected levels of dissemination, energy delivery and investment requirements using available diffusion models

Using the past diffusion trends of four renewable energy technologies for irrigation water pumping in India (SPV pumps, windmill pumps and biogas/producer gas driven dual fuel engine pumps), results of an attempt to project their future dissemination levels, have been presented in this study. The likely contribution of the renewable energy options considered in the study to the projected energy demand for irrigation water pumping in India has been estimated. Estimates of the associated investment requirements taking into account the learning effect have also been presented.     

炼油装置余热回收汽暖改水暖集中供热方案研究

为回收炼厂丰富的低温余热用于生活区的集中供暖,本文对余热资源和生活区采暖热负荷分别进行了综合标定和统计计算,确定采用回收余热、汽暖改水暖的集中供热系统方案。技术经济分析表明,该方案的节能效果和经济效益十分显著。     

Techno-economic evaluation of biohydrogen production from wastewater and agricultural waste

The world is facing serious climate change caused in part by human consumption of fossil fuel. Therefore, developing a clean and environmentally friendly energy resource is necessary given the depletion of fossil fuels, the preservation of the earth's ecosystem and self-preservation of human life. Biological hydrogen production, using dark fermentation is being developed as a promising alternative and renewable energy source, using biomass feedstock. In this study, beverage wastewater and agricultural waste were examined as substrates for dark fermentation to produce clean biohydrogen energy.     

Critical analysis of the European Union directive which regulates the use of biofuels: An approach to the Spanish case

For more than a decade we have lived in a period where the so-called “sustainability” is crucial and is motivated primarily by the social awareness of achieving a balance between human development and the conservation of the environment. This philosophy has a direct and inevitable impact on business and politics. Governments have long since been developing standards and encouraging various diverse initiatives whose aim is to defend the environment.In recent times, the global debate on the environment has been centred on CO₂ emissions. This gas is the major cause of the “greenhouse effect” and people are more concerned with the idea that the emissions of this gas should be minimized. As a result of this concern, the Kyoto Protocol was enacted and subscribed to by many countries, setting the maximum gas emissions for them.Fossil fuels are a major source of CO₂ emissions. In 2003 the European Union (EU) directive 2003/30/EC [2003/30/EC Directive of the European Parliament and the Council—8th may 2003. On the promotion of the use of biofuels or other renewable fuels for transport] was developed with the aim of promoting the use of biofuels as a substitute for diesel or petrol among European Union countries as well as to contribute to fulfilling the commitments on climate change, security of supply in environmentally friendly conditions and the promotion of renewable energy sources.In order to achieve these goals, the directive forces all EU members to ensure that at least 5.75% of all petrol and diesel fuels sold for transport purposes are biofuels before December 31 of 2010. European Union countries have social and economic characteristics unique to themselves. The energy dependence from foreign sources, the features of the agricultural sector or the degree of industrialization varies greatly from one country to another. In this context, it is questionable whether the obligation imposed by this directive applies to achieve uniform and/or identical goals in each of the countries involved and whether the actions of the various governments are also aligned with these goals.     

Optimum design of hybrid renewable energy systems: Overview of different approaches

Public awareness of the need to reduce global warming and the significant increase in the prices of conventional energy sources have encouraged many countries to provide new energy policies that promote the renewable energy applications. Such renewable energy sources like wind, solar, hydro based energies, etc. are environment friendly and have potential to be more widely used. Combining these renewable energy sources with back-up units to form a hybrid system can provide a more economic, environment friendly and reliable supply of electricity in all load demand conditions compared to single-use of such systems. One of the most important issues in this type of hybrid system is to optimally size the hybrid system components as sufficient enough to meet all load requirements with possible minimum investment and operating costs. There are many studies about the optimization and sizing of hybrid renewable energy systems since the recent popular utilization of renewable energy sources. In this concept, this paper provides a detailed analysis of such optimum sizing approaches in the literature that can make significant contributions to wider renewable energy penetration by enhancing the system applicability in terms of economy.