Climate change mitigation with integration of renewable energy resources in the electricity grid of New South Wales,Australia

The implementation of climate change mitigation strategies may significantly affect the current practices for electricity network operation. Increasing penetration of renewable energy generation technologies into electricity networks is one of the key mitigation strategies to achieve greenhouse gas emission reduction targets. Additional climate change mitigation strategies can also contribute to emission reduction thereby supplementing the renewable energy generation participation, which may be limited due to technical constraints of the network. In this paper, the penetration requirements for different renewable energy generation resources are assessed while concurrently examining other mitigation strategies to reduce overall emissions from electricity networks and meet requisite targets. The impacts of climate change mitigation strategies on the demand and generation mix are considered for facilitating the penetration of renewable generation. New climate change mitigation indices namely change in average demand, change in peak demand, generation flexibility and generation mix have been proposed to measure the level of emission reduction by incorporating different mitigation strategies. The marginal emissions associated with the individual generation technologies in the state of New South Wales (NSW) are modelled and the total emissions associated with the electricity grid of NSW are evaluated.     

U.S. state policies for renewable energy: Context and effectiveness

Over the past decade, state policies on renewable energy have been on the rise in the U.S., providing states with various options for encouraging the generation of renewable electricity. Two promising policies, the Renewable Portfolio Standard (RPS) and the Mandatory Green Power Option (MGPO), have been implemented in many states but the evidence about their effectiveness is mixed. In this paper, we argue that recognizing the natural, social, and policy context under which MGPO and RPS are adopted is necessary in order to measure their true effectiveness. This is because the context rather than the policy might lead to positive outcomes and there is the possibility for sample bias. When controlling for the context in which the policies are implemented, we find that RPS has a negative impact on investments in renewable capacity. However, we find that investor-owned utilities seem to respond more positively to RPS mandates than publicly owned utilities. By contrast, MGPO appears to have a significant effect on installed renewable capacity for all utilities regardless of the context in which it is implemented.     

The link between renewable energy production and gross domestic product in Africa: A comparative study between 1980 and 2008

Renewable energy (RE) projects are arguably one of the most important strategies that can be used in the mitigation of climate change impacts. At the same time, RE technologies can generate clean energy and potentially boost the economy of the African continent. It is thus not surprising that recent studies have investigated the relationship between RE and economic growth in some African countries. However, the limitation of these reductionist analytical frameworks is that they can conceal the true regional picture in terms of the link between investments in RE technologies and gross domestic product (GDP). This holistic analysis is important in order to inform regional policies on climate change. The article uses statistical analytic techniques to examine the correlation between RE production and economic growth across different blocks of the African continent between 1980 and 2008. The analysis is between geographical blocks (e.g. Southern Africa, Western Africa, etc.) and between oil and non-oil producing blocks. Generally speaking, while there exists a similar pattern in all the studied blocks in terms of mean, standard deviation and correlation between RE and GDP, a few exceptions can be found. For instance, the rise in RE-GDP correlation from 1992/1993 onwards was conspicuously higher in North Africa and oil-producing countries compared to all the other blocks. Similarly, Southern Africa was the only block where the correlation between RE and GDP was negative throughout the period under review, except 1988, 1989 and 1997 when it was positive.     

Role of renewable energy technologies in rural communities' adaptation to climate change in Nepal

The aim of this paper is to analyze the role of renewable energy technologies (RETs) such as biogas, improved cooking stoves (ICSs), micro hydro (MH) and solar power (SP) in helping rural communities in Nepal to adapt to climate change. The analysis considers the energy efficiency of different RETs as well as their socio-economic and environmental impacts. The efficient use of biomass in new technology, such as biogas and ICSs for cooking, has increased energy security and reduced the negative effects of traditional biomass usage. MH and SP systems are replacing candles and kerosene lamps, and are the most promising RET models for electricity generation in rural Nepal. The improved illumination from these technologies also produces better education, health, environments, and social harmony in rural communities. This study uses the Long-range Energy Alternatives Planning model (LEAP) model to develop a plan for long-term RETs use in Nepal, and specifically focuses on household energy use in rural areas. It assesses the role of biogas and ICSs in rural communities and climate change adaptation in Nepal, along with the potential role of MH and SP technologies. According to the LEAP analysis, the planned implementation of MH for 20-year long-term will result in the reduction of 2.553 million tons of CO₂ emissions. Similarly SP, biogas, and ICSs will result in a reduction in CO₂ emissions of 5.214 million tons, 35.880 million tons, and 7.452 million tons, respectively.     

Technology learning for renewable energy: Implications for South Africa's long-term mitigation scenarios

Technology learning can make a significant difference to renewable energy as a mitigation option in South Africa's electricity sector. This article considers scenarios implemented in a Markal energy model used for mitigation analysis. It outlines the empirical evidence that unit costs of renewable energy technologies decline, considers the theoretical background and how this can be implemented in modeling. Two scenarios are modelled, assuming 27% and 50% of renewable electricity by 2050, respectively. The results show a dramatic shift in the mitigation costs. In the less ambitious scenario, instead of imposing a cost of Rand 52/t CO₂-eq (at 10% discount rate), reduced costs due to technology learning turn renewables into negative cost option. Our results show that technology learning flips the costs, saving R143. At higher penetration rate, the incremental costs added beyond the base case decline from R92 per ton to R3. Including assumptions about technology learning turns renewable from a higher-cost mitigation option to one close to zero. We conclude that a future world in which global investment in renewables drives down unit costs makes it a much more cost-effective and sustainable mitigation option in South Africa.     

Mitigating energy-related GHG emissions through renewable energy

An inventory of greenhouse gas emissions from various economic sectors in Lebanon was conducted following the guidelines set by the World Meteorological Organization and United Nations Environment Programme Intergovernmental Panel on Climate Change. The inventory indicated that the energy sector is the major contributor (74%) to greenhouse gas emissions. This paper describes the inventory of energy related GHG emissions and assesses mitigation options to reduce emissions from electricity generation with emphasis on the usage of renewable energy including biomass, hydropower, solar and wind resources. Policy options for overcoming barriers hindering the exploitation of renewable energy resources are discussed in the context of country-specific characteristics.     

Biohydrogen as a renewable energy resource—Prospects and potentials

Biohydrogen holds the promise for a substantial contribution to the future renewable energy demands. It seems particularly suitable for relatively small-scale, decentralized systems, integrated with agricultural and industrial activities or waste processing facilities. Biohydrogen is considered as an important key to a sustainable world power supply and is currently being seen as the versatile fuel of the future, with the potential to replace fossil fuels. It has the key prospective to become the ideal means among the range of renewable H₂ production technologies presently existing. This review attempts to delineate the prospects and potentials of biohydrogen as renewable energy resource.     

Analysis of the EU renewable energy directive by a techno-economic optimisation model

The EU renewable energy (RES) directive sets a target of increasing the share of renewable energy used in the EU to 20% by 2020. The Norwegian goal for the share of renewable energy in 2020 is 67.5%, an increase from 60.1% in 2005. The Norwegian power production is almost solely based on renewable resources and the possibility to change from fossil power plants to renewable power production is almost non-existing. Therefore other measures have to be taken to fulfil the RES directive. Possible ways for Norway to reach its target for 2020 are analysed with a technology-rich, bottom-up energy system model (TIMES-Norway). This new model is developed with a high time resolution among others to be able to analyse intermittent power production. Model results indicate that the RES target can be achieved with a diversity of options including investments in hydropower, wind power, high-voltage power lines for export, various heat pump technologies, energy efficiency measures and increased use of biodiesel in the transportation sector. Hence, it is optimal to invest in a portfolio of technology choices in order to satisfy the RES directive, and not one single technology in one energy sector.     

Breaking down the silos: the integration of energy efficiency, renewable energy, demand response and climate change

This paper explores the feasibility of integrating energy efficiency program evaluation with the emerging need for the evaluation of programs from different “energy cultures” (demand response, renewable energy, and climate change). The paper reviews key features and information needs of the energy cultures and critically reviews the opportunities and challenges associated with integrating these with energy efficiency program evaluation. There is a need to integrate the different policy arenas where energy efficiency, demand response, and climate change programs are developed, and there are positive signs that this integration is starting to occur.

The vulnerability of renewable energy to climate change in Brazil

Energy supply in Brazil relies heavily on renewable energy source. The production of energy from renewable sources, however, greatly depends on climatic conditions, which may be impacted in the future due to global climate change (GCC). This paper analyzes the vulnerabilities of renewable energy production in Brazil for the cases of hydropower generation and liquid biofuels production, given a set of long-term climate projections for the A2 and B2 IPCC emission scenarios. The most important result found in this study is the increasing energy vulnerability of the poorest regions of Brazil to GCC. Both biofuels production (particularly biodiesel) and electricity generation (particularly hydropower) may negatively suffer from changes in the climate of those regions. Other renewable energy sources—such as wind power generation—may also be vulnerable, raising the need for further research. However, the results found are fundamentally dependent on the climate projections which, in turn, are still highly uncertain with respect to the future evolution of greenhouse gas emissions, greenhouse gas concentrations in the atmosphere and GCC. Therefore, in such long-term scenario analyses, the trends and directions derived are the ones to be emphasized rather than the precise results one arrives.     

Renewable energy policy in Turkey with the new legal regulations

Since the energy crises in the 1970’s, public and private decision makers are considering how to achieve a sustainable transition from fossil fuel based energy to sustainable and clean energies - namely renewable energies. Combined with the improvement of energy efficiency and the rational use of energy, renewable energy can provide everything fossil fuels currently offer in terms of heating and cooling, electricity generation and transportation. Renewable energy technologies posses many long term benefits including energy security, job creation, business opportunities, sustainable development and prevention of global warming.Turkey’s population is growing at an annual rate of 1.04%. If Turkey uses only traditional energy sources, it simply will not have enough energy capacity for its population. Renewable energy sources have the potential to make a large contribution to Turkey’s sustainable and independent energy future.Turkey aims to utilize its energy potential, including from renewable sources in a cost-effective manner. Turkey targets the share of renewable resources in electricity generation to be at least 30% by 2023 has in its 2009 Electricity Market and Security of Supply Strategy. Positive achievements have been obtained in renewable energy development and manufacturing in Turkey over the past decade. The renewable energy related legislation has been intensified. To meet its 30% target, the current promotion mechanism for renewable sources of electricity relies on feed-in tariffs for different renewable energy sources. Large hydropower is already competitive to conventional fossil-based electricity, so feed-in tariffs in the new RE Law are set to facilitate expanding the deployment of other, less mature renewable energy technologies.     

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.     

Simulation and optimization of a stand-alone power plant based on renewable energy sources

By using the optimization software tool HOMER, this project aims at the energetic and economical optimization of a RES-based stand-alone system, already installed at Leicestershire, UK. Based on local meteorological data, an optimization strategy has been developed to identify the most economical and efficient scenarios for the generation of electricity to cover the desirable load in annual basis. Furthermore, the environmental-friendly character of the system was highly concerned in terms of emissions reduction, therefore the capability of an off-grid system was also investigated. The simulations show that an off-grid project with zero emissions is feasible, presenting the additional advantage of minimal capital investment costs. Finally, it is found that grid connection corresponds to very high operational costs in a long term.     

Climate change implications for wind power resources in the Northwest United States

Using statistically downscaled output from four general circulation models (GCMs), we have investigated scenarios of climate change impacts on wind power generation potential in a five-state region within the Northwest United States (Idaho, Montana, Oregon, Washington, and Wyoming). All GCM simulations were extracted from the standardized set of runs created for the Intergovernmental Panel on Climate Change (IPCC). Analysis of model runs for the 20th century (20c3m) simulations revealed that the direct output of wind statistics from these models is of relatively poor quality compared with observations at airport weather stations within each state. When the GCM output was statistically downscaled, the resulting estimates of current climate wind statistics are substantially better. Furthermore, in looking at the GCM wind statistics for two IPCC future climate scenarios from the Special Report on Emissions Scenarios (SRES A1B and A2), there was significant disagreement in the direct model output from the four GCMs. When statistical downscaling was applied to the future climate simulations, a more coherent story unfolded related to the likely impact of climate change on the region's wind power resource. Specifically, the results suggest that summertime wind speeds in the Northwest may decrease by 5–10%, while wintertime wind speeds may decrease by relatively little, or possibly increase slightly. When these wind statistics are projected to typical turbine hub heights and nominal wind turbine power curves are applied, the impact of the climate change scenarios on wind power may be as high as a 40% reduction in summertime generation potential.     

A superstructure model of an isolated power supply system using renewable energy: Development and application to Jeju Island,Korea

In this study, we aim to develop a superstructure-based optimization model using mixed integer linear programming (MILP) to determine the optimal combination and sizing for a hybrid renewable energy system to be used in an isolated area. The developed model has a three-layered energy structure to reflect the current reality in which energy production and consumption sites are generally separate. A variety of economic factors, including distance between facilities and an installation area, are considered for a more accurate estimation of the total annualized cost. Two types of optimization models, i.e., with and without a battery, are proposed to evaluate the economic and technical effects of a storage device to resolve operation issues caused by intermittent resources. An application case study on Jeju Island, Korea, confirms that the proposed model is suitable for decision making at the planning stage of a renewable energy system.     

Design and feasibility analysis of hydrogen based hybrid energy system: A case study

Renewable energy sources can produce less carbon than conventional energy sources, which has the significant disadvantage of being intermittent, which triggers a stable storage system. This work focuses on the issues of hydrogen energy storage which can solve the fluctuating output power problem by simulating results on HOMER software. Three combinations of the Solar-Hydrogen system, Wind-Hydrogen system, and Solar-Wind-Hydrogen hybrid system are presented to find the most optimum one. Levelized Cost of Energy (LCOE) for Hybrid System has proven to be the most economical while the Wind Turbine cost 1.476% higher and the Solar Photovoltaics (PV) System costs 108.03% more. LCOE for Hybrid Model is $0.3387, while for Solar System it is $ 0.7046 and for Wind System it is $ 0.3437. These results show that a hydrogen-based energy storage system is viable for the considered.     

Successful renewable energy development in a competitive electricity market: A Texas case study

The development of renewable energy in markets with competition at wholesale and retail levels poses challenges not present in areas served by vertically-integrated utilities. The intermittent nature of some renewable energy resources impact reliability, operations, and market prices, in turn affecting all market participants. Meeting renewable energy goals may require coordination among many market players.     

Cost efficient utilisation of biomass in the German energy system in the context of energy and environmental policies

The possible uses of biomass for energy provision are manifold. Gaseous, liquid and solid bioenergy carriers can be alternatively converted into heat, power or transport fuel. The contribution of the different utilisation pathways to environmental political targets for greenhouse gas (GHG) emission reduction and energy political targets for the future share of renewable energy vary accordingly to their techno-economic characteristics. The aim of the presented study is to assess the different biomass options against the background of energy and environmental political targets based on a system analytical approach for the future German energy sector. The results show that heat generation and to a lower extent combined heat and power (CHP) production from solid biomass like wood and straw are the most cost effective ways to contribute to the emission reduction targets. The use of energy crops in fermentation biogas plants (maize) and for production of 1st generation transportation fuels, like biodiesel from rapeseed and ethanol from grain or sugar beet, are less favourable. Optimisation potentials lie in a switch to the production of 2nd generation biofuels and the enhanced use of either biomass residues or low production intensive energy crops.     

Exploring the feasibility of green hydrogen production using excess energy from a country-scale 100% solar-wind renewable energy system

When planning large-scale 100% renewable energy systems (RES) for the year 2050, the system capacity is usually oversized for better supply-demand matching of electrical energy since solar and wind resources are highly intermittent. This causes excessive excess energy that is typically dissipated, curtailed, or sold directly. The public literature shows a lack of studies on the feasibility of using this excess for country-scale co-generation. This study presents the first investigation of utilizing this excess to generate green hydrogen gas. The concept is demonstrated for Jordan using three solar photovoltaic (PV), wind, and hybrid PV-wind RESs, all equipped with Lithium-Ion battery energy storage systems (ESSs), for hydrogen production using a polymer electrolyte membrane (PEM) system. The results show that the PV-based system has the highest demand-supply fraction (>99%). However, the wind-based system is more favorable economically, with installed RES, ESS, and PEM capacities of only 23.88 GW, 2542 GWh, and 20.66 GW. It also shows the highest hydrogen annual production rate (172.1 × 10³ tons) and the lowest hydrogen cost (1.082 USD/kg). The three systems were a better option than selling excess energy directly, where they ensure annual incomes up to 2.68 billion USD while having payback periods of as low as 1.78 years. Furthermore, the hydrogen cost does not exceed 2.03 USD/kg, which is significantly lower than the expected cost of hydrogen (3 USD/kg) produced using energy from fossil fuel-based systems in 2050.