Abstract: Renewable energies (RE) in Chile and around the world have experienced outstanding growth in recent years. However, RE technologies such as solar photovoltaic and wind generate an imbalance between generation (offer) and consumption (demand) because of their intermittent and variable nature. Moreover, RE & rsquo;s natural variability makes it necessary for conventional technologies to play a significant role in adjusting for the imbalance in the electric system frequency. As variable RE penetration grows, the need for frequency regulation will increase and, depending on how those higher costs are financed, this could lead to a disincentive to invest in conventional plants that provide that service. In this paper we study the impact of increased photovoltaic energy penetration, the leading RE in Chile, on the profitability of different conventional generation technologies. Specifically, we analyze the role that the frequency control remuneration mechanism has on that impact. For this purpose, four different solar photovoltaic penetration scenarios are simulated in Chile & rsquo;s Northern System, comparing two payment criteria for frequency regulation services: i) a cost-based pricing system whose payments relate to the incurred costs and ii) a market-based pricing system where the marginal cost of providing the services is paid. The results show that as installed photovoltaic capacity increases, the average marginal cost of energy (operation cost) decreases due to a displacement of more expensive power plants, but at the same time, investment cost may increase. In the long run, contract prices change as a result of falling operational costs and rising investment cost, resulting in changes in the profitability of all technologies. Finally, while both cost-based and market-based systems reward the ability to regulate frequency, the technologies performing the regulation receive different payments for the service, affecting both their profitability and the incentives for investment.

Abstract: Over the past decade, the promotion of renewable energy projects in Chile, especially solar energy projects, has become increasingly important, as energy dependence from foreign fossil fuels has increased and concerns regarding climate change continue to grow, posing a significant challenge to the local economy. Even though recent developments toward a more sustainable energy matrix in Chile have significantly increased the investment in the solar energy sector, social and environmental fragilities, combined with the lack of well-functioning institutions and the historical marginalization of indigenous communities who have been affected by several energy projects, result in gradually increasing conflictive situations. Unless proper mechanisms are designed and implemented to rapidly and correctly address these challenges, Chile could miss the opportunities that solar energy projects can provide to the development of its communities and to the economic growth of its regions. This article studies solar photovoltaics planning in Chile, focusing on the recent developments and the main challenges ahead, and proposes policy recommendations for effectively addressing these challenges.

Abstract: A series of six new Cu(i) complexes with ([Cu(N-{4-R}pyridine-2-yl-methanimine)(PPh3)Br]) formulation, where R corresponds to a donor or acceptor p-substituent, have been synthesized and were used to study self-association effects on their structural and electrochemical properties. X-ray diffraction results showed that in all complexes the packing is organized from a dimer generated by supramolecular pi stacking and hydrogen bonding. H-1-NMR experiments at several concentrations showed that all complexes undergo a fast-self-association monomer-dimer equilibrium in solution, while changes in resonance frequency towards the high or low field in specific protons of the imine ligand allow establishing that dimers have similar structures to those found in the crystal. The thermodynamic parameters for this self-association process were calculated from dimerization constants determined by VT-H-1-NMR experiments for several concentrations at different temperatures. The values for K-D (4.0 to 70.0 M-1 range), Delta H (-1.4 to -2.6 kcal mol(-1) range), Delta S (-0.2 to 2.1 cal mol(-1) K-1 range), and Delta G(298) (-0.8 to -2.0 kcal mol(-1) range) are of the same order and indicate that the self-dimerization process is enthalpically driven for all complexes. The electrochemical profile of the complexes shows two redox Cu(ii)/Cu(i) processes whose relative intensities are sensitive to concentration changes, indicating that both species are in chemical equilibrium, with the monomer and the dimer having different electrochemical characteristics. We associate this behaviour with the structural lability of the Cu(i) centre that allows the monomeric molecules to reorder conformationally to achieve a more adequate assembly in the non-covalent dimer. As expected, structural properties in the solid and in solution, as well as their electrochemical properties, are not correlated with the electronic parameters usually used to evaluate R substituent effects. This confirms that the properties of the Cu(i) complexes are usually more influenced by steric effects than by the inductive effects of substituents of the ligands. In fact, the results obtained showed the importance of non-covalent inte

Abstract: Biochemical methane potential (BMP) test is a key analytical technique to assess the implementation and optimisation of anaerobic biotechnologies. However, this technique is characterised by long testing times (from 20 to > 100 days), which is not suitable for waste utilities, consulting companies or plants operators whose decision-making processes cannot be held for such a long time. This study develops a statistically robust mathematical strategy using sensitivity functions for early prediction of BMP first-order model parameters, i.e. methane yield (B-0) and kinetic constant rate (k). The minimum testing time for early parameter estimation showed a potential correlation with the k value, where (i) slowly biodegradable substrates (k <= 0.1 d(-1)) have a minimum testing times of >= 15 days, (ii) moderately biodegradable substrates (0.1 < k < 0.2 d(-1)) have a minimum testing times between 8 and 15 days, and (iii) rapidly biodegradable substrates (k > 0.2 d(-1)) have testing times lower than 7 days. (C) 2017 Elsevier Ltd. All rights reserved.

Abstract: The different oxygen affinities of ammonia-oxidizing (AOB) and nitrite-oxidizing bacteria (NOB) are often used to define the operational strategy to achieve partial nitritation (PN) required before the anammox (AMX) process. For this purpose, apparent kinetic parameters are mainly used in the case of granular sludge, which can lead to errors when defining the operational conditions to obtain only nitritation (avoiding nitratation). In the present study, a mathematical methodology is proposed to determine the intrinsic kinetic parameters of AOB and NOB in granular sludge based on data obtained by respirometric assays. Additionally, the oxygen affinity constant (K-O2) and maximum specific rate (r(max)) of flocculent and granular sludge sample, produced under mainstream and sidestream conditions were determined at various temperatures (15, 20 and 30 degrees C). The results show that for granules, the intrinsic K-O2 and r(max) values were lower and higher, respectively, than the apparent values. Furthermore, the K-O2 values for flocs and granules at all of the tested temperatures were lower for NOB than for AOB. The values obtained for the kinetic parameters indicated that it is impossible to maintain partial nitritation by only controlling the dissolved oxygen concentration.

Abstract: Following the trend observed in developed economies, various Latin American governments are committed to reducing greenhouse gas emissions, particularly in the power sector. In countries such as Chile, Peru, Colombia, Brazil, and Mexico, various regulatory policies have been issued to meet renewable-generation integration targets and satisfy the increasing demand from consumers for supply quality. Meanwhile, the integration of distributed generation (DG) in rural and urban areas as well as the increasing need to integrate electric vehicles (EVs) in urban areas are driving important reforms in the distribution sector.

Abstract: In recent years, the development of renewable energies in the electricity market in Chile has gained significant attention as a key alternative for energy sources diversification and meeting three key policy objectives: energy availability, environmental protection, and social-economic development. This study aims to assess various renewable energy sources in order to select suitable sources to accomplish the different policy goals in a country like Chile. For this purpose, a Multi-Criteria Decision Analysis (MCDA) method is employed to evaluate the relative importance of policy objectives. In addition, a sensitivity analysis is conducted to build various different policy scenarios measuring the impact of variations on the current weights of the decision criteria. The results show that solar, wind, and small hydro are the preferred sources in the Chilean renewable energy portfolio, maximizing the objective of meeting the three policy goals at the same time.

Abstract: Chile has become one of the first few countries where renewable sources compete directly with conventional generation in price-based auctions. Moreover, the results of energy auctions during the last few years show a remarkable transition from conventional fossil fuels to renewable energies. In fact, the energy auction in 2017, to provide energy to customers from distribution companies, achieved a massive expansion in renewable technology at one of the lowest prices in the world. These positive results prompted the question if such results were permanent or temporal due to factors with limited effects. In this regard, this paper studies the key factors that drove the significant rise of renewable technologies in Chilean energy auctions, obtaining valuable lessons for regulators, not only in Chile, but also in the region and the world. For this purpose, we considered a well-proven method based on a hybrid multicriteria decision-making model to examine and prioritize the main drivers of the expansion of renewables in auctions. The results showed that some specific characteristics of the auction design, particularly the hourly supply blocks, the lead time for project construction, and contract duration, were the most significant drivers for the expansion of renewables in energy auctions. Moreover, the results showed that, provided that the auction design accommodates for such drivers, solar energy ends up as the most attractive technology in the Chilean auctions. The research also shows the main findings are robust by the application of a probabilistic sensitivity analysis.

Abstract: In the last decade, the importance of exploiting Chile's Renewable Energy Sources (RESs) has increased significantly, as fossil fuel prices have risen and concerns regarding climate change issues grown, posing an important threat to its economy. However, to date, the advancement of Renewable Energy Technologies (RETs) in the country has been very limited due to various barriers. For this reason, identifying and mitigating the main barriers that hamper the advancement of RETs is necessary to allow the successful deployment of these technologies. Based on data collected from a questionnaire survey and interviews conducted among the major renewable project developers, the authors identify and rank the major barriers to the adoption of renewable energy technologies in Chile. Our findings show that the most significant barriers include grid connection constraints and lack of grid capacity, longer processing times for a large number of permits, land and/or water lease securement and limited access to financing. Furthermore, we discuss the most critical barriers in detail together with policy recommendations to overcome them.

Abstract: The emergence of high penetration rates of renewable energies in power systems presents a serious challenge in energy generation and load balance maintenance to ensure power network stability and reliability. Energy Storage Systems (ESSs) could play a relevant role in facing these challenges, as the technologies have passed the demo and prototype phases to a wide market implementation phase. The only remaining barrier for their implementation is their cost, but even this barrier is quickly disappearing. In this paper, we address the financial feasibility of storage technologies in electricity systems. In particular, we evaluate whether such technologies are economically sustainable and how far they are from becoming viable. For this purpose, we consider the Chilean electricity system and evaluate the maximum possible arbitrage revenues that could be achieved under ESS through benefiting from energy time shift, diminishing of transmission losses, and transmission upgrade deferral. The results show that the arbitrage revenues are still below the cost of storage systems. Further improvement in storage efficiency or a decrease in the cost of storage systems is still needed to make this type of investment financially viable in the near future.