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The results of an experimental study of a high-energy spark ignition system with self-stabilization of the discharge current are presented. A description of the physical principle that provides self-stabilization is given. The effect of a high-speed gas flow on such parameters of a spark discharge as discharge current, resistance of the discharge gap, voltage across the spark gap, the energy input into the spark discharge, the duration and efficiency of the input is studied.

Abstract A model is developed to investigate the effect of energy investment on economic growth under a set of simplifying assumptions. The economy is treated as a two sector aggregate; the energy sector and the rest of the economy, whereas the model describing the energy-economy interaction is linear to the differential changes of the variables, adaptable to structural evolution and requires a modest amount of data for initialization. It can be used in a single stage or an iterative mode to produce outcomes for the short and medium run. The analysis reveals that energy productive investment has had an impact on the rate of formation of the non-energy capital stock and subsequently on economic growth. These effects appear amplified under a regime of increasing energy price.

Abstract The economic giant China, enjoying miraculously high economic performance since the 1980s, is currently facing an economic performance slowdown, along with environmental sustainability challenges. Energy-industry investments might serve as a potential driver of economic performance, indirectly inducing environmental sustainability through investments in the energy-industry transition from old technology to a renewable one. This research provides an empirical assessment of the causal bond between energy-industry investment and economic performance across the regional development levels, employing a dynamic longitudinal data modeling on China’s 27 provincial and municipality units from 1997 through 2017. It developed an economic performance model to incorporate energy-industry investment as an aggregate production growth input. The core empirical findings are as follows. Firstly, the energy-industry investment and economic performance induced a positive and statistically significant mutual influence, manifested from their parameter estimates. Secondly, a bilateral causal bond is unveiled between energy-industry investment and economic performance based on the Dumitrescu-Hurlin technique, confirming the feedback hypothesis of a causal bond between the two variables. The results are consistent across the under-analysis panels in terms of the nature of the influence; however, the induced degrees of their influence significantly differed across the regional development levels. The intensity of the direct influence of energy-industry investment (0.049) on economic performance lags behind the feedback influence of economic performance (1.069) on energy-industry investment. Additionally, considerable heterogeneities are detected in influence intensities across the regional panels. Eastern China (region of high development) displayed the most substantial direct (0.058) and feedback influence (1.193), while western China manifested the least substantial intensity of direct (0.030) and feedback influence (0.836). After that, the central China (region of medium development) demonstrated a medium intensity of direct (0.037) and feedback influence (0.996). Finally, among other regressors, human capital, physical capital, inflation rate, and trade presented a positive and significant influence on economic performance. In contrast, the foreign direct investment significantly influenced the economic performance only in the eastern China. The empirical findings implied that energy-industry investment might serve as a vital driver of economic performance, with the most significant role in the highly developed regions and the least significant in the low developed regions, given the important explanatory variables. Based on empirical findings, policies are suggested.

Abstract The electricity sector in the Galapagos Islands is heavily dependent on fossil fuels for electricity generation but only a few renewable sources are used for such a purpose in this archipelago. Therefore, this work aims to present the current status of its electricity sector and show estimates for the upcoming years, discuss exploited and unexploited renewable resources, and put forward a proposal for a hybrid system to generate renewable power. Currently, thermoelectric power plants run on diesel are the main source of electricity generation in the archipelago due to supplying 85% of the total power installed in the islands (27.6 MW), and the remaining 15% (7.3 MW) is from renewable sources, such as the wind (10.8%), sun (4.1%), and vegetable oils (0.1%). In the upcoming years, there will be a growth in the use of these renewable resources if an additional capacity of 28.5 MW is installed. The gross electric output generated by this sector in the last twelve months (March 2017 - February 2018) was 53.80 GWh, which has allowed a return on revenues of over five million dollars at an average cost of US $0.10/kWh. Based on the existing renewable resources in the Galapagos Islands, the implementation of a hybrid solar/biogas power generation system is an attractive alternative to support the zero-fossil fuel initiative, diversify the energy matrix, and promote local development. However, sustainable development policies, energy efficiency programs and foreign investment funds to carry out new projects are required to ensure a bright future for the electricity sector in the Galapagos.

Abstract The objective of this research is to examine the relationship between real per capita output and carbon dioxide emissions, both globally and by groups of countries. We used panel data from 151 countries for the period 1980–2016. The countries are classified according to income levels using the World Bank Atlas Method. The argument behind this classification is that the strength of the relationship between the two variables differs according to the income levels of countries. Based on the theoretical framework of the Kuznets environmental curve, we found that there is a strong U-shaped relationship between the two variables in middle-high and low income countries. The hypothesis of the Kuznets environmental curve holds true in high-income and middle-high income countries. The inclusion of additional covariants shows that urbanization has a positive and significant relationship with carbon dioxide emissions middle-high and middle-low income countries. Energy consumption and manufacturing have a positive and statistically significant relationship with carbon dioxide emissions in all the groups of countries. A possible implication of economic policy derived from our research is that incentives to production should focus on activities that use environmentally friendly technologies to limit the irreversible damage caused by contamination.

The microgrid (MG) has emerged as part of the technological transition to smart grids. The MG can operate in two modes: connected to a distribution network or in an isolated stand-alone way. When the transition to island mode occurs, the M G must operate in a stable, reliable, and resilient way. In this context, the distributed energy resources (DERs) that are part of the M G must respond optimally to guarantee dynamic voltage stability (DVS) and to improve operational resilience. Under resilient contingency conditions, the voltage stability and reactive power control of the MG is severely compromised. Therefore, even though DERs based on smart inverters operate according to the low-voltage ride-through (L VRT) requirements stated at the IEEE Standard 1547–2018, it is not enough to supply the reactive power deficit. Thus, this paper aims to include FACTS (flexible ac transmission systems) type compensation devices, particularly a static var compensator (SVC) that operates in coordination with DERs of the MG. The results obtained are satisfactory, and it is shown that the smart inverters used for the DERs and the SVC device operating with a coordinated control strategy improved the DVS, allowing the control of the reactive power supply and granting an adequate level of operational resilience in the isolated MG.

Effects of climate change on water resources availability have been studied extensively; however, few studies have explored the sensitivity of water to several factors of change. This study aimed to explore the sensitive of water balance in water resources systems due to future changes of climate, land use and water use. Dynamical and statistical downscaling were applied to four global climate models for the projections of precipitation and temperature of two climate scenarios RCP 4.5 and RCP 8.5. Land use projections were carried out through a combination of Markov chains and cellular automata methods. These projections were introduced in a hydrologic model for future water supply evaluation, and its interactions with water use projections derived from a statistical analysis which served to assessment deficits and surplus in water to 2050. This approach was applied in the Machangara river basin located in the Ecuadorian southern Andes. Results showed that the water supply exceeds the water demand in most scenarios; however, taking into account the seasonality, there were months like August and January that would have significant water deficit in joint scenarios in the future. These results could be useful for planners formulating actions to achieve water security for future generations.

Abstract This study analyses the measures used to promote renewable energy for electricity generation in the 18 Latin American countries that signed the Paris Agreement, in an electricity demand growth context. The Latin American countries have had a remarkable growth in the use of renewable energy for electricity generation. Biomass, wind and solar energy have experienced strong growth, however, their participation in the energy mix remains small. All the studied countries have established renewable energy targets, 16 having adopted at least one promotion measure. The most used measures are tax incentives, mainly through exemptions in income tax, value added or sales tax and on tariffs. Also, most countries are using auction systems, which are replacing the Feed-In Tariff system. The net metering system adoption is also growing in the region. The results of the study show a positive relationship between the most active countries in renewable energy promotion and the performance achieved in the studied years. Therefore active policies are considered necessary for the future development of renewable energies.

Abstract In this work, we used solar energy converted via photosynthesis into chemical energy of the biomass of the fast-growing perennial herb Miscanthus × giganteus for the manufacture of nanocellulose (NC) films, which are biodegradable alternative to common petroleum-based polymer substrates used in flexible electronics. To create the NC substrates, we applied an environmentally friendly method of organosolv delignification of plant raw materials carried out at a low temperature and in a relatively short time. Then by means of the low-temperature cheap and scalable method Successive Ionic Layer Adsorption and Reaction (SILAR) we deposited copper iodide (CuI) film of 0.72 µm thickness on both sides of the 12 µm thick NC substrate, and thus obtained light-weight and flexible biodegradable nontoxic thermoelectric material CuI/NC. Crystal structure, morphology, chemical composition, and optical, electrical and thermoelectric properties of the CuI/NC have been researched. Studies have shown that nanostructured p-type semiconductor CuI film in the CuI/NC TE material is quite dense and completely covers the NC surface. It has typical optical direct band gap ≈ 3.0 eV, is single-phase γ-CuI with crystallite sizes in the 19–25 nm range, with moderate dislocation density of (1.6–2.8) × 1015 lines/m2, and tolerable microstrains e of (4–9) × 10−3 a.u. The determined value of the Seebeck coefficient S is ~228 μV K−1, at that, S is constant in the temperature range 290–335 K. Together with the thermoelectric power factor ≈ 36 μW·m−1·K−2it is favorable for the use of CuI/NC as new thermoelectric material for an in-plane design of biodegradable flexible thin film thermoelectric generator (TEG). At temperature gradient of 50 K, the single p-CuI thermoelectric leg made from CuI/NC strip of 3 cm long and 0.5 cm wide generates open circuit voltage 8.4 mV, short circuit current 0.7 µA and maximum output power 1.5 nW. It corresponds to the output power density 10 µW/m2, and thus confirms the suitability of CuI/NC to obtain electricity by the harvesting the waste environmental heat.