NGOs and green electricity

Electricity from renewable energy sources is by definition the environmental “green” product. Sales of green power are usually supported by marketing campaign images of a melting ice cap, polar bears in danger and other environmental catastrophes. Greenprices this month takes a closer look at NGOs, organisations whose task is to raise the environmental awareness of the public, and to try to understand how they position themselves today on the green electricity market. There are to date three ways by which non-governmental organisations can play a role on the market for electricity from renewable energy sources: promoting, selling and labelling green electricity.     

Review of green electricity production in Slovenia

The article presents a short review of electricity production from renewable energy sources in Slovenia. In Introduction the term of “green electricity” is defined. Comparison of structures of electricity production is presented for the years 1990 and 2003. The main part of the article presents an approximate data for technical and theoretical potentials of renewable energy sources in Slovenia. State-of-the-art regarding individual technologies of electricity production from renewable energy sources and political targets according to Directive 2001/77/EC for green electricity are also presented. At the end of the article different stimulation models are described and uniform prices and premiums for the purchase of green electrical energy are presented.     

Electrolyser-based energy management: a means for optimising the exploitation of variable renewable-energy resources in stand-alone applications

Electrolyser-based energy management (EBM) offers a versatile means for optimising the process of harnessing energy supplies derived from variable and/or intermittent renewable resources, e.g. solar (photo-voltaic), wind, wave and tidal. In general, EBM systems consist of an electrolyser, water and gas (hydrogen and, optimally, oxygen) storage and management systems and a means of (re-) generating electricity, e.g. a fuel cell. Such systems achieve their management via energy conversion and storage, this operational principle being referred to as electricity supply-and-demand management (ESDM). Implementation of this principle offers significant advantages in the utilisation of variable and/or intermittent renewable resources, as it permits electricity generated during periods of high-availability/low-demand to be “time-shifted” for subsequent re-supply during periods of low-availability/high-demand. Furthermore, EBM systems have the important advantage over other ESDM systems that the stored form of energy is readily utilisable as a pollution-free gas supply for thermal end-uses. This reconversion route significantly enhances the overall energy-conversion efficiency. Electrolyser and fuel cells based upon proton-exchange membrane technologies are preferred because these afford considerable operational advantages over any alternatives. In this paper these advantages are expanded upon and preliminary data based on these ideas are presented.     

New scenario of the non-conventional renewable energies on Chile after the incentives created on the “Short Law I”

Non-conventional renewable energies have never played an important role in the Chilean energy generation system, mainly due to the economic barriers that actually exists on our country for the inclusion of these kinds of technologies. Nevertheless, the use of renewable energy system technologies have started to be an interesting issue for the Chilean government, and for that reason, the last modification of the Energy Law during 2004, usually known as “Short Law I”, introduced the first direct incentive to renewable energy generation (specifically in the art. 71-7).In this work we analyze in detail the modification on the electric law we mentioned before, especially for geothermal and wind power generation, and we compare the economic incentive generated with the new law and the differences between the real energy costs using renewable energy systems technologies and the current energy price in Chile. It is clear from the analysis that the total incentives do not cover more than 8.3% of the price differences between incomes and costs.     

GIS-based environmental assessment of wind energy systems for spatial planning: A case study from Western Turkey

Increasing population and life standards causes fossil fuel consumption to increase. Due to this increasing consumption, fossil fuels are being depleted rapidly. In addition to rapid exhaustion, another important problem associated with fossil fuels is that their consumption has major negative impacts on the environment. Therefore, many countries around the world have included renewable energy systems (RES) in their future energy plans so that they can produce reliable and environmentally friendly energy. Parallel to this trend, various RES have been identified and recently integrated into the current energy network of Turkey as well. However, it should be recognized that renewable energy resources are not fully environmentally safe. Different RES are associated with different environmental impacts. In planning the future energy development of a country, evaluation of renewable energy resources potentials together with their associated environmental impacts is critical. The aim of this study is to create a decision support system for site selection of wind turbines using Geographic Information System (GIS) tools. Wind energy potential and environmental fitness/acceptability are used as decision criteria for the site selection process. Potential environmental impacts of wind generation are identified in accordance with Turkish legislations and previous studies; and represented as fuzzy objectives of the decision problem. Wind potential map of Turkey generated by General Directorate of Electrical Power Resources Survey and Development is used to identify economically feasible locations in terms of wind energy generation. A study area composed of Usak, Aydin, Denizli, Mugla, and Burdur provinces in Turkey is selected and divided into 250 m × 250 m grids. Each grid represents an alternative location for a wind turbine or group of wind turbines. Fuzzy environmental objectives such as “Acceptable in terms of noise level”, “Acceptable in terms of bird habitat”, “Acceptable in terms of safety and aesthetics” and “Safe in terms of natural reserves” associated with wind turbines are identified based on previous research and each of these objectives are represented by a fuzzy set. Individual satisfaction degree of each of these environmental objectives for each grid is calculated. Then these individual satisfactions are aggregated into an overall satisfaction degree using various aggregator operators such as “and”, “or”, and “order weighted averaging.” Thus, an overall satisfaction degree of all the environmental objectives is obtained for each grid in the study area. A map of environmental fitness is developed in GIS environment by using these overall satisfaction degrees. Then this map is utilized together with the wind potential map of Turkey to identify both potentially and environmentally feasible wind turbine locations within the study area.     

Contribution of green labels in electricity retail markets to fostering renewable energy

In European countries, retailers are obliged to disclose the energy source and the related environmental impacts of their portfolio over the preceding year. The electricity supplied in the Dutch retail market is presented as renewable energy for 34%, but this relatively high share is for 69% based on certificates (Guarantees of Origin) which are imported from in particular Norway. The certificates are used to sell green electricity to consumers. The premium for green electricity which is actually paid by Dutch consumers is no more than a few percentages of the retail price. The low level of this premium is related to the abundant supply of certificates at low marginal costs from Norway. This also means that the premium for green electricity is too low to give an incentive for investments in new capacity. Hence, the current labelling system for renewable electricity is mainly valuable, besides being an instrument for tracking and tracing of renewable energy, as a marketing instrument for electricity retailers. The effectiveness of Guarantees of Origin as a policy instrument to foster renewable electricity sources is weak. This effectiveness can be raised by implementing restrictions on the international trade or the issuance of new certificates.     

The evolution of flexibility mechanisms for achieving European renewable energy targets 2020—ex-ante evaluation of the principle mechanisms

In December 2008, the European Council and the European Parliament agreed on a final compromise for a new European renewable energy directive. One of the most debated issues prior to this compromise was the design of “target flexibility mechanisms”, which should allow member states with low or expensive renewable energy potential to partly fulfil their national renewable energy target in other countries. This article traces back the political discussion that has led to the evolution of the different flexibility options. It then evaluates the most prominent flexibility mechanisms against a set of qualitative criteria. It concludes that free or restricted certificate trade based on guarantees of origin (GOs) – as proposed earlier by the European Commission – is not a viable option due to some “knockout” criteria, despite other potential advantages. The mechanisms that have replaced GO trade in the final compromise – joint projects, joint support schemes and statistical transfer between member states – provide less flexibility, but score better against a number of other important criteria. The crucial question for the coming years is how their utilisation can be facilitated. One first step might be that proactive member states define open design issues for implementing the mechanisms.     

Recent developments in EHD Enhanced Heat Transfer

This paper considers that the case for using electrohydrodynamic (EHD) enhancement of heat transfer has been established, especially in thermodynamic renewable energy applications where temperature levels are relatively low. It goes on to establish the basis on which nucleate boiling heat transfer is enhanced by EHD forces at surfaces designed to improve condensation, giving experimental results for a six-tube, shell/tube heat exchanger boiling R12 at “Io-fin” surfaces as well as for single-tube tests using “Thermoexcel” and “Gewa-T” surfaces.     

Hawaii: RE in the Island State

Hawaii is blessed with a variety of renewable energy resources,” says Representative Mina Morita, who chairs the state House of Representatives committee on energy and the environment. “Lots of sunshine, strong, reliable trade winds, fast-growing crops, flowing streams, geothermal heat, and both hot and cold ocean waters.” Tom Koppel looks at Hawaii's renewable energy potential, the extent to which it is being utilized, and at new developments that are either in the works or being proposed.     

Renewable energy: a response to climate change

“We recognize the importance of renewable energy for sustainable development, diversification of energy supply, and preservation of the environment. We will ensure that renewable energy sources are adequately considered in our national plans and encourage others to do so as well. We encourage continuing research and investment in renewable energy technology, throughout the world”.Communique from the G8 Leaders’ Summit, Genoa, July 2001.The Third Assessment Report of the IPCC confirmed that the Earth’s climate is changing as a result of human activities, particularly from energy use, and that further change is inevitable. Natural ecosystems are already adapting to change, some are under threat, and it is evident that human health and habitats will be affected world-wide. Such climate changes could also affect the present supplies of renewable energy sources and the performance and reliability of the conversion technologies. This paper concentrates on the reduction of carbon dioxide emissions and the role that the global renewable energy industry might play in this regard. (The five other major greenhouse gases are given less emphasis here.) The paper compares the costs of renewable energy systems with fossil fuel-derived energy services and considers how placing a value on carbon emissions will help provide convergence. The move towards a de-carbonised world, driven partly by climate change science and partly by the business opportunities it offers, will need to occur sooner rather than later if an acceptable stabilisation level of atmospheric carbon dioxide is to be achieved. Government policy decisions made now will determine the sort of future world we wish our children to inherit. The renewable energy era has begun.     

Sustainable energy planning based on a stand-alone hybrid renewableenergy/hydrogen power system: Application in Karpathos island, Greece

This study presents the sustainable planning of a renewables-based energy system, which aims to fulfil the electric needs of the island by replacing the existing diesel generators with new wind farms, photovoltaic installations and hydrogen production systems. Electric system design and least cost planning analysis were concluded using historic data from both demand and supply sides. An optimal “sustainable island” scheme should ensure 100% use of renewable energy resources for power generation, while hydrogen production is ideal for covering storage and transportation needs. Due to its morphology and scale, Karpathos applies perfectly for wind and solar energy systems, due to increased solar resource (about 1790 kWh/m².year of global irradiation) and high wind potential (average of 9 m/s in specific locations). Therefore, this case study examines an increase in RES penetration up to 20% in the electric energy mixture, a hydrogen production plan just for the needs of transport and a more aggressive, 100% renewables scheme that ensures a self-fulfilling energy system based on indigenous renewable resources.     

Truncated chlorophyll antenna size of the photosystems—a practical method to improve microalgal productivity and hydrogen production in mass culture

Unicellular microalgae hold the promise of commercial exploitation in mass culture for hydrogen and biomass production. In any microalgal production system, the achievable photosynthetic productivity and light utilization efficiency of the algae are the single most important factors in the determination of cost. Microalgal mass cultures growing under full sunlight have a low per chlorophyll (Chl) productivity since, at high photon flux densities, the rate of photon absorption by the Chl antenna far exceeds the rate at which photons can be utilized for photosynthesis. Excess photons are dissipated as fluorescence or heat. Up to 80% of absorbed photons could thus be wasted, reducing light conversion efficiencies and cellular productivity to fairly low levels. This shortcoming could possibly be alleviated by the development of microalgal strains with a limited number of Chl molecules in the light-harvesting antenna of their photosystems, i.e., strains that have a truncated Chl antenna size. It is expected that individually, such microalgae will not be able to saturate rates of photosynthesis and, thus, will not be subject to wasteful dissipation of excitation energy. In turn, the productivity of the mass culture will be improved. The method of choice to reach the objective of a “truncated light-harvesting Chl antenna” size (tla) employed DNA insertional and chemical mutagenesis of the unicellular green algae Chlamydomonas reinhardtii and Dunaliella salina, followed by a rigorous screening protocol to identify mutants with a smaller light-harvesting Chl antenna size. Molecular and genetic analyses of isolated tla strains were performed. Biochemical and physiological analyses in terms of photosynthetic productivity and light conversion efficiencies are presented. The results show that a truncated Chl antenna size of PSII is more important than that of PSI in terms of the photosynthetic productivity of a mass culture. A list of genes that confer a “truncated light-harvesting Chl antenna” size to green algae is being compiled for future application in algal hydrogen and biomass production.     

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.     

Full-energy-chain analysis of greenhouse gas emissions for solar thermal electric power generation systems

Renewable energy generation of electricity is advocated as a means of reducing carbon dioxide emissions associated with the generation from fossil fuels. Whilst it is true that renewable sources do not generate significant carbon dioxide whilst producing electricity, as with fossil-fuelled plants they do embody significant emissions in their materials of construction. The “full-chain” environmental impacts of wind, hydro, solar-thermal and photovoltaic conversion are quite different and the likely trend in future reduction of embodied energy of next generation systems reflects the relative maturity of each technology. There has been much recent development of solar thermal electricity generation options for which there is a wide divergence in embodied CO₂ emissions.     

Solar absorption system for water desalination

There is growing international concern about pollution caused by chlorofluorocarbons (CFCs) and emissions of oxides of carbon, sulphur and nitrogen from fossil fuel sources. This has stimulated research to develop “environmentally-friendly” systems powered by renewable energies. This paper examines the application of a novel absorption system for water desalination. The absorption system could be powered by a renewable energy source (e.g. solar energy) or by a hybrid method (e.g. solar energy and natural gas). The absorption system offers several attractive features, including a high performance ratio, no pre-treatment required, extraction of water at low temperatures, absence of scaling, and minimal corrosion. Water is used as the working fluid and so the system is attractive on environmental grounds. The paper describes computer modelling of the system and its potential applications.     

Design optimization for the hybrid power system of a green building

This paper proposes an optimal design procedure for a green building equipped with renewable energy, energy storages, and proton exchange membrane fuel cells (PEMFCs). First, we introduce the hybrid power system of the green building and construct a simulation model using Matlab/SimPowerSystem?. The model parameters are tuned so that the system responses can be estimated without extensive experiments in the optimization processes. Second, we define the cost and reliability indexes to optimize the system design using three steps: component selection, component sizing, and power management (PM) adjustment. We further define the safety index to evaluate the system's sustainability under extreme conditions when no renewable energy is available. Last, we apply the proposed procedures to the green building and demonstrate the benefits of the optimal design. The proposed method can be directly applied to develop customized hybrid power systems in the future.     

10% from renewables? The potential contribution from an HK schools PV installation programme

Hong Kong (HK) is currently assessing its future policy on renewable energy and public consultation indicates greater support for renewable energy than previously envisaged, including “willingness-to-pay” for green electricity and also that the present (1% by 2012, 2% by 2017 and 3% by 2022) targets are too conservative. This paper considers the role of de-centralised energy generation by looking at sector-by-sector energy generation and use, in this paper, schools. In HK, schools are horizontally biased compared with the vertical emphasis of other sectors. This paper assesses the contribution of the extensive photovoltaic (PV) arrays installed on the Ma Wan School to meet 10% of the School's annual electricity demand based on the first four months data and compared with the project inception simulation studies plus the impact of a specially developed Schools Building Energy Management System (BEMS) to raise awareness of energy efficient use in classrooms. The project—jointly funded by the HK Government and the research institute of the local utility, CLP RI,—was the pilot for small-scale grid-connection technical and non-technical issues and also identified the need for specially trained PV installation engineers.     

Utilities' role in deploying renewables

The aim of this paper is to review the current status and prospects of the renewable energy sources that are more suitable for the production of electricity, and to present the views of the EURE Group on the role electricity utilities could play in deploying generating plants based on these sources. In the first part of the paper, reference is made both to the renewable sources that have long been used for these purposes, such as hydro power, and to the “new” ones, particularly bioenergy, photovoltaics and wind power. Mention is also made of other technologies that have so far been less developed or can be applied only locally (e.g. geothermal energy). In the second part, the paper advises on the way utilities could contribute to renewable energy research and how they could help promoting these sources.     

Development of a test facility for photovoltaic-diesel hybrid energy systems

To quantify the potential for performance improvements of photovoltaic-diesel (PV-diesel) hybrid energy systems, a test facility has been installed at the Centre for Renewable Energy Systems Technology. The research facility is part of the cooperative program to develop improved power conditioning systems for the provision of electricity in remote areas (ACRE Project 4.1). A customised control interface has been developed using the control and data acquisition software, LabVIEW. The graphical user-interface supports the automatic or manual definition of control parameters, which allows the system designer to apply optimal control methods for the management of PV-diesel hybrid energy systems. Continuously monitored weather data supports the integration of photovoltaic resource and load demand forecasts as part of the control strategy. The paper describes the developed test facility and discusses the potential for performance improvements of stand-alone renewable energy systems, which can be achieved through the application of “intelligent” energy management strategies.     

Comparison of fuel characteristics of green (renewable) diesel with biodiesel obtainable from algal oil and vegetable oil

To fulfill the need of renewable, sustainable, and cleaner form of fuel, scientists are attracted toward biodiesel and hydrotreated vegetable oil or green (renewable) diesel. Biodiesel is generally obtained from vegetable oil by the process of transesterification while green diesel is obtained by hydrogenation. However, chemically both are completely different and thus their physical properties are highly affected. In present work, authors have compared the important properties of Pongamia biodiesel, algal biodiesel and hydrotreated vegetable oil. It is observed that both the biofuels may be blended for use in diesel engines as this will complement their fuel characteristics.