121 resultados para renewables


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Frequent locations of thermal fronts in UK shelf seas were identified using an archive of 30,000 satellite images acquired between 1999 and 2008, and applied as a proxy for pelagic diversity in the designation of Marine Protected Areas (MPAs). Networks of MPAs are required for conservation of critical marine habitats within Europe, and there are similar initiatives worldwide. Many pelagic biodiversity hotspots are related to fronts, for example cetaceans and basking sharks around the Isle of Man, Hebrides and Cornwall, and hence remote sensing can address this policy need in regions with insufficient species distribution data. This is the first study of UK Continental Shelf front locations to use a 10-year archive of full-resolution (1.1 km) AVHRR data, revealing new aspects of their spatial and seasonal variability. Frontal locations determined at sea or predicted by ocean models agreed closely with the new frequent front maps, which also identified many additional frontal zones. These front maps were among the most widely used datasets in the recommendation of UK MPAs, and would be applicable to other geographic regions and to other policy drivers such as facilitating the deployment of offshore renewable energy devices with minimal environmental impact.

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Waste glycerol was converted to secondary amines in a one pot reaction, using Clostridium butyricum and catalytic hydrogen transfer-mediated amination.

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Infraventus – Internationalizing a Renewables Business to Kenya Infraventus is a renewable energy development company, with a consolidated experience, since 1988, in developing, constructing and operating projects mainly in Portugal, but also in other countries: Spain, Poland, France, Australia, Finland and Panama, and is now regarding Kenya as a possible destiny. Kenya is the biggest economy of East Africa, with a growing GDP around 5% and a low level of electric grid coverage thru its territory, 33% of national access to electricity. Kenya energy policy is intended to promote the investment in renewables; wind and sun are existing resources in good measures. Kenya is an interesting destiny to Infraventus, but has many risks. The objective of this dissertation is to evaluate the possible advantages of this investment and risks and propose recommendations about how to mitigate them considering alternative entry mode

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The recent proposals presented by EPA aimed to reduce the dependency of fossil fuels and to lower current emissions levels, hoping to gradually shift electric generation units to renewable energy sources. Actually, the Final Rule Proposal announcement day exhibited a negative Abnormal Return on Fossil Fuels but the following days had positive Abnormal Returns, mostly due to legislative change perceived by financial markets which eased up implementation periods of the proposed measures in the Final Rule when compared to the Draft Rule. Oppositely, Renewables and Solar Portfolios exhibited negative Cumulative Abnormal Returns over the period surrounding the Final Rule.

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This paper provides an overview of the reduction targets that Ireland has set in the context of decarbonising their electricity generation through the use of renewables. The main challenges associated with integrating high levels (>20% of installed capacity) of non-dispatchable renewable generation are identified. The rising complexity of the challenge as renewable penetration levels increase is highlighted. A list of relevant research questions is then proposed, and an overview is given into the previous work that has gone into answering some of them. In particular, studies into the Irish energy market are identified, the current knowledge gap is described, and areas of necessary future research are suggested

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The variability of renewable energy is widely recognised as a challenge for integrating high levels of renewable generation into electricity systems. However, to explore its implications effectively, variability itself should first be clearly understood. This is particularly true for national electricity systems with high planned penetration of renewables and limited interconnection such as the UK. Variability cannot be considered as a distinct resource property with a single measurable parameter, but is a multi-faceted concept best described by a range of distinct characteristics. This paper identifies relevant characteristics of variability, and considers their implications for energy research. This is done through analysis of wind, solar and tidal current resources, with a primary focus on the Bristol Channel region in the UK. The relationship with electricity demand is considered, alongside the potential benefits of resource diversity. Analysis is presented in terms of persistence, distribution, frequency and correlation between supply and demand. Marked differences are seen between the behaviours of the individual resources, and these give rise to a range of different implications for system integration. Wind shows strong persistence and a useful seasonal pattern, but also a high spread in energy levels at timescales beyond one or two days. The solar resource is most closely correlated with electricity demand, but is undermined by night-time zero values and an even greater spread of monthly energy delivered than wind. In contrast, the tidal resource exhibits very low persistence, but also much greater consistency in energy values assessed across monthly time scales. Whilst this paper focuses primarily on the behaviour of resources, it is noted that discrete variability characteristics can be related to different system impacts. Persistence and predictability are relevant for system balancing, whereas statistical distribution is more relevant when exploring issues of asset utilisation and energy curtailment. Areas of further research are also identified, including the need to assess the value of predictability in relation to other characteristics.

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Thermal generation is a vital component of mature and reliable electricity markets. As the share of renewable electricity in such markets grows, so too do the challenges associated with its variability. Proposed solutions to these challenges typically focus on alternatives to primary generation, such as energy storage, demand side management, or increased interconnection. Less attention is given to the demands placed on conventional thermal generation or its potential for increased flexibility. However, for the foreseeable future, conventional plants will have to operate alongside new renewables and have an essential role in accommodating increasing supply-side variability. This paper explores the role that conventional generation has to play in managing variability through the sub-system case study of Northern Ireland, identifying the significance of specific plant characteristics for reliable system operation. Particular attention is given to the challenges of wind ramping and the need to avoid excessive wind curtailment. Potential for conflict is identified with the role for conventional plant in addressing these two challenges. Market specific strategies for using the existing fleet of generation to reduce the impact of renewable resource variability are proposed, and wider lessons from the approach taken are identified.

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Electric power grids throughout the world suffer from serious inefficiencies associated with under-utilization due to demand patterns, engineering design and load following approaches in use today. These grids consume much of the world’s energy and represent a large carbon footprint. From material utilization perspectives significant hardware is manufactured and installed for this infrastructure often to be used at less than 20-40% of its operational capacity for most of its lifetime. These inefficiencies lead engineers to require additional grid support and conventional generation capacity additions when renewable technologies (such as solar and wind) and electric vehicles are to be added to the utility demand/supply mix. Using actual data from the PJM [PJM 2009] the work shows that consumer load management, real time price signals, sensors and intelligent demand/supply control offer a compelling path forward to increase the efficient utilization and carbon footprint reduction of the world’s grids. Underutilization factors from many distribution companies indicate that distribution feeders are often operated at only 70-80% of their peak capacity for a few hours per year, and on average are loaded to less than 30-40% of their capability. By creating strong societal connections between consumers and energy providers technology can radically change this situation. Intelligent deployment of smart sensors, smart electric vehicles, consumer-based load management technology very high saturations of intermittent renewable energy supplies can be effectively controlled and dispatched to increase the levels of utilization of existing utility distribution, substation, transmission, and generation equipment. The strengthening of these technology, society and consumer relationships requires rapid dissemination of knowledge (real time prices, costs & benefit sharing, demand response requirements) in order to incentivize behaviors that can increase the effective use of technological equipment that represents one of the largest capital assets modern society has created.

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On 11 October 2013, the CEOs of 10 large European energy utilities issued a warning that the European energy infrastructure is “in jeopardy” and called for an end to support for renewables on grounds that wind and solar were mature technologies that no longer required such support. Given the unlikelihood, however, that EU decision-makers would renege on their decarbonisation or renewable energy targets, Fabio Genoese asks in this commentary whether it would not be a better strategy for conventional generators to explore new business models built around a ‘reliability pricing system’, in which nearly 100% reliability would be guaranteed for base load but not for peak demand.

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Low-carbon energy technologies are pivotal for decarbonising our economies up to 2050 while ensuring secure and affordable energy. Consequently, innovation that reduces the cost of low-carbon energy would play an important role in reducing transition costs. We assess the two most prominent innovation policy instruments (i) public research, development and demonstration (RD&D) subsidies and (ii) public deployment policies. Our results indicate that both deployment and RD&D coincide with increasing knowledge generation and the improved competitiveness of renewable energy technologies. We find that both support schemes together have a greater effect that they would individually, that RD&D support is unsurprisingly more effective in driving patents and that timing matters. Current wind deployment based on past wind RD&D spending coincides best with wind patenting. If we look into competitiveness we find a similar picture, with the greatest effect coming from deployment. Finally, we find significant cross-border effects, especially for winddeployment. Increased deployment in one country coincides with increased patenting in nearby countries. Based on our findings we argue that both deployment and RD&D support are needed to create innovation in renewable energy technologies. However, we worry that current support is unbalanced. Public spending on deployment has been two orders of magnitude larger (in 2010 about €48 billion in the five largest EU countries in 2010) than spending on RD&D support (about €315 million). Consequently, basing the policy mix more on empirical evidence could increase the efficiency of innovation policy targeted towards renewable energy technologies.

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Summary. For more than two decades, the development of renewable energy sources (RES) has been an important aim of EU energy policy. It accelerated with the adoption of a 1997 White Paper and the setting a decade later of a 20% renewable energy target, to be reached by 2020. The EU counts on renewable energy for multiple purposes: to diversify its energy supply; to increase its security of supply; and to create new industries, jobs, economic growth and export opportunities, while at the same time reducing greenhouse gas (GHG) emissions. Many expectations rest on its development. Fossil fuels have been critical to the development of industrial nations, including EU Member States, which are now deeply reliant upon coal, oil and gas for nearly every aspect of their existence. Faced with some hard truths, however, the Member States have begun to shelve fossil fuel. These hard truths are as follows: firstly, fossil fuels are a finite resource, sometimes difficult to extract. This means that, at some point, fossil fuels are going to be more difficult to access in Europe or too expensive to use.1 The problem is that you cannot just stop using fossil fuels when they become too expensive; the existing infrastructure is profoundly reliant on fossil fuels. It is thus almost normal that a fierce resistance to change exists. Secondly, fossil fuels contribute to climate change. They emit GHG, which contribute greatly to climate change. As a consequence, their use needs to be drastically reduced. Thirdly, Member States are currently suffering a decline in their own fossil fuel production. This increases their dependence on increasingly costly fossil fuel imports from increasingly unstable countries. This problem is compounded by global developments: the growing share of emerging economies in global energy demand (in particular China and India but also the Middle East) and the development of unconventional oil and gas production in the United States. All these elements endanger the competitiveness of Member States’ economies and their security of supply. Therefore, new indigenous sources of energy and a diversification of energy suppliers and routes to convey energy need to be found. To solve all these challenges, in 2008 the EU put in place a strategy based on three objectives: sustainability (reduction of GHG), competitiveness and security of supply. The adoption of a renewable energy policy was considered essential for reaching these three strategic objectives. The adoption of the 20% renewable energy target has undeniably had a positive effect in the EU on the growth in renewables, with the result that renewable energy sources are steadily increasing their presence in the EU energy mix. They are now, it can be said, an integral part of the EU energy system. However, the necessity of reaching this 20% renewable energy target in 2020, combined with other circumstances, has also engendered in many Member States a certain number of difficulties, creating uncertainties for investors and postponing benefits for consumers. The electricity sector is the clearest example of this downside. Subsidies have become extremely abundant and vary from one Member State to another, compromising both fair competition and single market. Networks encountered many difficulties to develop and adapt. With technological progress these subsidies have also become quite excessive. The growing impact of renewable electricity fluctuations has made some traditional power plants unprofitable and created disincentives for new investments. The EU does clearly need to reassess its strategy. If it repeats the 2008 measures it will risk to provoke increased instability and costs.

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In the last few years, several EU member states have reduced support to renewable energy, leading to numerous claims that these policy changes retroactively affected existing investments and that the practice of ‘grandfathering’ should have been observed. Among these, the case of Spain stands out, both due to the material size of the cuts and the large volume of investments affected, although the Czech Republic, Bulgaria, Poland, Romania and Italy have also introduced reforms with deleterious consequences to their renewable energy sectors.